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Soft Tissue

Superpage 2

Revised: 19 October 2013
Copyright: (c) 2001-2013, PathologyOutlines.com, Inc.

Fibroblastic / myofibroblastic tumors

General


Reviewer: Komal Arora, M.D. (see Reviewers page)
Revised: 6 July 2012, last major update July 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.

General
=========================================================================

● Large subset of mesenchymal tumors
● Cells / tumors may have both fibroblastic and myofibroblastic features



Fibroblastic / myofibroblastic tumors of soft tissue

Normal histology of soft tissue


Reviewer: Komal Arora, M.D. (see Reviewers page)
Revised: 19 July 2012, last major update July 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.

General
=========================================================================

● Fibrous tissue consists of fibroblasts and extracellular matrix
● Extracellular matrix consists of collagen, elastin and ground substance

Fibrous tissue:
● Loose or dense
● Dense fibrous tissue includes tendons (connect muscle to bone), ligaments (connect bones or cartilage to each other), aponeuroses (ribbon like tendinous expansion)

Fibroblasts:
● Spindled (along collagen fibers) to stellate (star shaped-in myxoid areas)
● Produce various collagens
● Positive for vimentin, actin

Fibrocytes:
● Quiescent stage of fibroblasts

Myofibroblasts:
● Modified fibroblasts with multiple possible origins (see diagram below), including transition from fibroblasts during tissue repair (J Invest Dermatol 2007;127:526)
● Features are intermediate between fibroblasts and smooth muscle cells

Diagrams
=========================================================================



Myofibroblast progenitors

Micro images
=========================================================================



Extracellular matrix compliance controls development of the myofibroblast phenotype in three-dimensional collagen gels


NIH/3T3 Mouse fibroblasts in cell culture


Myofibroma: interface of myofibroblastic tumor with normal collagen

Additional references
=========================================================================

Wikipedia-fibroblasts, Wikipedia-myofibroblasts, Am J Pathol 2007;170:1807



Fibroblastic / myofibroblastic tumors

Angiomyofibroblastoma


Reviewer: Komal Arora, M.D. (see Reviewers page)
Revised: 19 July 2012, last major update July 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.

General
=========================================================================

● Benign, well-circumscribed myofibroblastic tumor, usually in vulva
● May overlap with cellular angiofibroma
● First described in 1992 (Am J Surg Pathol 1992;16:373)

Clinical description
=========================================================================

● Uncommon slow growing painless mass, usually females of reproductive age

Sites
=========================================================================

● Usually vulvar, 10-15% in vagina
● Also scrotum or paratesticular soft tissue in men (median age 57 years)

Treatment
=========================================================================

● Excision, only rarely recurs, does not metastasize

Case reports
=========================================================================

● 27 year old man with inguinal tumor (Arch Pathol Lab Med 2000;124:1679)
● 48 year old woman with pedunculated vulvar mass (Acta Med Okayama 2006;60:237)
● 49 year old man with scrotal mass (Univ Oklahoma)
● 80 year old woman with sarcomatous transformation in vulva (Am J Surg Pathol 1997;21:1104)
● Recurrence in vagina (Eur J Gynaecol Oncol 2007;28:324)

Gross description
=========================================================================

● Well circumscribed but not encapsulated, usually 5-7 cm or less, tan-pink soft cut surface, no necrosis

Gross images
=========================================================================



Scrotal mass

Micro description
=========================================================================

● Thin fibrous pseudocapsule, alternating hyper- and hypocellular areas with prominent thin walled and ectatic vessel in edematous stroma (Mod Pathol 1996;9:284)
● Round to spindled tumor cells have eosinophilic cytoplasm and often bi- or multi-nucleation
● May have plasmacytoid or epithelioid morphology, or rarely show degenerative changes
● Tumor cells are concentrated around vessels
● Mast cells common
● 10% have mature adipose tissue
● No/rare mitotic figures, no/rare red blood cell extravasation, no atypia
● Most menopausal patients have less cellularity, less edema but more fibrosis and vessel wall hyalinization

Micro images
=========================================================================



Numerous capillary-like vascular channels; spindle cells with occasional multinucleated cells

               
Scrotal mass-various images


Arising from posterior perivesical space

Positive stains
=========================================================================

● Vimentin, desmin (strong and diffuse, may be reduced in post-menopausal patients), ER, PR, smooth muscle actin or pan-muscle actin (focal, Hum Pathol 1997;28:1046), occasional CD34

Negative stains
=========================================================================

● S100, keratin

Electron microscopy description
=========================================================================

● Myofibroblastic and fibroblastic features

Differential diagnosis
=========================================================================

Aggressive angiomyxoma: not circumscribed, > 5 cm, less cellular, less vascular but vessels are large and thick walled, stromal mucin and RBC extravasation are present, infrequent plump stromal cells, usually actin negative
Cellular angiofibroma: more cellular uniformly, perivascular hyalinization and large, thick walled vessels, usually actin/desmin negative
Epithelioid leiomyoma: more cellular, no biphasic pattern, usually no binucleation, no/rare mast cells

Additional references
=========================================================================

Ultrastruct Pathol 2006;30:193, Stanford School of Medicine



Fibroblastic / myofibroblastic tumors

Calcifying aponeurotic fibroma


Reviewer: Komal Arora, M.D. (see Reviewers page)
Revised: 19 July 2012, last major update July 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.

Definition
=========================================================================

● Rare, slow growing, painless tumor with fibroblasts palisading around chondroid or calcified nodules, usually in hands and feet of children or young adults; rarely at other sites (Hum Pathol 1998;29:1504)
● Also called juvenile aponeurotic fibroma

Clinical description
=========================================================================

● 50% recur, especially in children
● Does not metastasize
● May be cartilaginous analog of fibromatosis

Treatment
=========================================================================

● Conservative excision with reexcision as necessary for recurrences

Case reports
=========================================================================

● 2 year old child with giant intramuscular calcifying aponeurotic fibroma of gluteus maximus (Ann Trop Paediatr 2010;30:259)
● 10 year old girl with elbow tumor (J Med Invest 2011;58:159)
● 16 year old girl with foot tumor (Case of the Week #47)
● 36 year old woman with distal phalangeal bone involvement (Korean J Radiol 2008;9:91)
● Recurrent tumor of the thumb (J Hand Surg Am 2011;36:110)

Clinical images
=========================================================================



46 year old woman

   
36 year old woman with distal phalangeal bone involvement

Gross description
=========================================================================

● Nodular or infiltrative gray-white, gritty mass in subcutaneous tissue or tendon, may be calcified, usually 3 cm or less in hands or feet, may be larger elsewhere

Micro description
=========================================================================

● Nodules of plump or epithelioid fibroblasts palisading around cartilage and spotty calcification
● Cells have indistinct and variable cytoplasm, plump oval nuclei with vesicular chromatin that may be condensed below nuclear membrane
● Fibrocytes in stroma between nodules have dense, evenly dispersed chromatin
● May infiltrate fat or striated muscle at periphery
● Frequent osteoclast-like giant cells
● Rare mitotic figures, no atypia
● More cellular in very young

Micro images
=========================================================================



Poorly circumscribed fibroproliferative process with scattered, linear and calcified zones


Amorphous calcification surrounded by palisading cells suggestive of rheumatoid nodule or crystals


Typical zonation pattern has cellular, plump fibroblastic cells palisading
around a hyalinized collagenous zone, which in turn surrounds the calcification



Cells adjacent to hyalinized layer are commonly more rounded


Chondroid area is adjacent to calcification

               
16 year old girl with foot tumor


36 year old woman with distal phalangeal bone involvement

Cytology description
=========================================================================

● Benign appearing spindle cells, chondroid cells, multinucleated giant cells and calcified debris (Diagn Cytopathol 2001;24:336)

Positive stains
=========================================================================

● Vimentin, CD68, CD99, S100, muscle specific actin (50%), smooth muscle actin (50%)

Negative stains
=========================================================================

● (Usually) CD34, CD57, PR

Electron microscopy description
=========================================================================

● Chondrocytes, fibroblasts and occasional myofibroblasts

Molecular
=========================================================================

● Benign, but may be aneuploid (Cancer 1994;73:1200)

Differential diagnosis
=========================================================================

Infantile fibromatosis: usually involves head, neck and proximal extremities in infants, not hands and feet of children/young adults, background is more myxoid than chondroid, calcification is rare
Superficial [palmar and plantar] and desmoid fibromatosis: usually no calcification or chondroid differentiation
Chondroma of soft parts: may involve hands, but usually well circumscribed with more well developed chondroid differentiation, no infiltration of adjacent tissue, no surrounding epithelioid cells
Fibrous hamartoma of infancy: immature mesenchyme, fibroblasts are arranged in trabeculae but no palisading, no cartilage or calcification, not hands and feet

Additional references
=========================================================================

Acta Orthop Belg 2001;67:412, Stanford University



Fibroblastic / myofibroblastic tumors

Calcifying fibrous tumor


Reviewer: Komal Arora, M.D. (see Reviewers page)
Revised: 5 September 2012, last major update July 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.

General
=========================================================================

● Benign fibrous lesion with abundant hyalinized collagen, psammomatous or dystrophic calcifications and lymphocytic infiltration
● Also called calcifying fibrous pseudotumor
● First described in 1993 (Am J Surg Pathol 1993;17:502)

Clinical description
=========================================================================

● Adolescents/young adults, all sites
● Not related to inflammatory myofibroblastic tumor (Mod Pathol 2001;14:784, Int J Surg Pathol 2002;10:189)

Treatment
=========================================================================

● Excision, rarely recurs

Case reports
=========================================================================

● 24 year old woman with neck mass (Arch Pathol Lab Med 2000;124:435)
● 32 year old woman with omental tumor (Case of Week #249)
● Tumors of small intestine (Ann Diagn Pathol 2008;12:138)
● Multiple peritoneal tumors (Ann Diagn Pathol 2007;11:460, Am J Clin Pathol 2003;119:811)
● Multiple pleural tumors (Virchows Arch 2005;446:78, J Thorac Oncol 2008;3:1356)
● Mesentry tumors (J Cancer Res Ther 2011;7:500, Int J Surg Pathol 2001;9:249)
● Stomach tumor (Am J Surg Pathol 2010;34:271)

Gross description
=========================================================================

● Well circumscribed but unencapsulated, variable size, may infiltrate into surrounding tissue, may have gritty cut surface

Gross images
=========================================================================



Gray-white tumor with whorled cut surface


Well circumscribed tumor (adrenal gland)

Micro description
=========================================================================

● Paucicellular fibroblastic proliferation with lymphocytes (possibly lymphoid follicles), plasma cells, eosinophils, mast cells, dense collagenous tissue, varying degrees of calcification
● Border is often at least partially infiltrative

Micro images
=========================================================================



Psammoma body and adjacent lymphoplasmacytic infiltrate; hypocellular stroma with psammomatous calcifications


Adrenal gland tumor has paucicellular fibrous proliferation with focal microcalcifications


Microcalcifications vary in size


Lymphoplasmacytic inflammation is characteristic


Figures A, B, E, F (comparison with inflammatory myofibroblastic tumor)


Hyalinized collagen with psammoma body

           
Omental tumor


Various images (adrenal gland)

Positive stains
=========================================================================

● Factor XIIIa, vimentin
● Also CD34

Negative stains
=========================================================================

● Smooth muscle actin, muscle specific actin, ALK, desmin, S100, keratin

Electron microscopy description
=========================================================================

● Immature fibroblastic cells, collagen fibrils, dystrophic and psammomatous calcifications

Electron microscopy images
=========================================================================



Spindle cells with intermediate filaments and collagen fibrils showing the fibroblastic nature of the cells

Differential diagnosis
=========================================================================

● Inflammatory myofibroblastic tumor: more cellular, no calcifications, ALK+, actin+, CD34+ and focally Factor XIIIa+ (Mod Pathol 2001;14:784, Int J Surg Pathol 2002;10:189)
● Idiopathic retroperitoneal fibrosis and related sclerosing fibroinflammatory lesions: more inflammation, especially plasma cells and eosinophils
● Desmoplastic fibroblastoma: older patients, low cellularity, larger prominent fibroblasts, no microcalcifications, no prominent inflammatory infiltrate
● Calcifying aponeurotic fibroma: more cellular, usually distal location, usually smaller lesion

Additional references
=========================================================================

Stanford University



Fibroblastic / myofibroblastic tumors

Cellular angiofibroma


Reviewer: Komal Arora, M.D. (see Reviewers page)
Revised: 19 July 2012, last major update July 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.

General
=========================================================================

● Benign, highly cellular tumor of vulva and scrotum/inguinal region with prominent blood vessels
● Also called angiomyofibroblastoma-like lesion
● First described in 1997 (Am J Surg Pathol 1997;21:636)
● Related to spindle cell lipoma and mammary-type myofibroblastoma, with morphological variations dependent on anatomic location (Mod Pathol 2011;24:82)
● In women, may arise from hormone receptor positive mesenchymal cells in lower female genital tract (Histopathology 2004;45:360)

Clinical features
=========================================================================

● Rare; usually ages 40+ years
● Extragenital cases have similar features (APMIS 2007;115:254)

Treatment
=========================================================================

● Excision with negative margins
● Usually does not recur (Am J Surg Pathol 2004;28:1426)

Case reports
=========================================================================

● 44 year old woman with leiomyomatous nodules (Virchows Arch 2009;454:595)
● 51 year old woman with coexisting Bartholin’s cyst (Sao Paulo Med J 2005;123:250)
● Recurrent tumor (J Clin Pathol 2002;55:477)

Gross description
=========================================================================

● Vulvar lesions are usually up to 3 cm, male lesions may reach 14 cm
● Well circumscribed nodules with soft to rubbery, gray-pink-brown cut surface

Micro description
=========================================================================

● Well circumscribed, variable pseudocapsule
● Cellular tumor with fascicles or haphazard pattern
● Bland spindle cells with scant, lightly eosinophilic cytoplasm with ill defined borders, oval to fusiform nucleus
● May be epithelioid
● Prominent small to medium-sized vessels with hyaline fibrosis in walls
● Vessels may have degenerative changes of fibrin thrombi, intramural inflammation, hemosiderin
● Some (usually 5% or less) adipose tissue present in 50%
● Stroma is usually fine collagenous fibers
● Scattered mast cells are common
● Female lesions may have brisk mitotic activity, usually absent/rare in males
● Occasional atypia or sarcomatous transformation (Am J Surg Pathol 2010;34:707)
● No necrosis, no atypical mitotic figures

Micro images
=========================================================================


       
Various images


Fusiform cells, thick walled blood vessels and adipose tissue


Fusiform cells with clear cytoplasm and bland nuclei;

       
Occasional features


Recurrent tumor

       
Malignant cases


ER+

Virtual slides
=========================================================================



63 year old man with scrotal mass

Positive stains
=========================================================================

● ER, PR, vimentin
● Smooth muscle actin (21%), CD34 (30-60%)

Negative stains
=========================================================================

● S100, desmin, EMA

Cytogenetics / Molecular
=========================================================================

● May have 13q14 involvement (Histopathology 2007;51:410)
● Similar changes as spindle cell lipoma (Cancer Genet Cytogenet 2007;177:131)
● FISH: monoallelic deletion of RB1

Differential diagnosis
=========================================================================

Aggressive angiomyxoma: usually large and deep, hypocellular, infiltrative margin, desmin+
Angiomyofibroblastoma: less uniform cellularity, smaller vessels, usually desmin+
Leiomyoma: spindled cytoplasm, actin+, desmin+
● Perineurioma
● PHAT
Solitary fibrous tumor: hyper- and hypocellular areas, prominent staghorn vessels, hyalinized collagen CD34+

Additional references
=========================================================================

Stanford School of Medicine, Histopathology 2009;54:156



Other tumors of skin

Dermatofibrosarcoma protuberans (DFSP)


Reviewer: Christopher Hale, M.D. (see Reviewers page)
Revised: 14 September 2012, last major update September 2012
Copyright: (c) 2001-2012, PathologyOutlines.com, Inc.

General
=========================================================================

● Part of WHO classification for skin tumors, not soft tissue tumors
● Low to intermediate grade malignancy, usually of dermis, with prominent storiform pattern of monomorphic fibroblast-like cells that invade into subcutis (Dermatofibrosarcoma Protuberans, eMedicine)
● Also called intermediate (borderline) fibrous histiocytoma
● Slow growing, low-grade malignant neoplasm of trunk and various sites but not hands and feet
● Rare, usually adults 20-40 years, more common in blacks in US (J Am Acad Dermatol 2007;56:968)
● Can occur in infants (Arch Dermatol 2007;143:203) and children (J Plast Reconstr Aesthet Surg 2009;62:819)
● May be a peculiar type of nerve sheath tumor since CD34 positive, or may derive from a subset of CD34 positive dermal dendritic cells
● Locally aggressive, low rate of metastasis (only after repeated failures at local control)
● May progress to fibrosarcoma or MFH
● Giant cell fibroblastoma is considered the juvenile variant of DFSP as it has the same translocation (Am J Surg Pathol 2003;27:27)

Bednar’s tumor:
● 5-10% of cases
● Pigmented variant due to dendritic cells with melanin, S100+ only in pigmented cells, HMB45 negative
● Associated with black patients

Case reports
=========================================================================

● Atrophic variant (J Dermatol 2006;33:486)
● Granular cell variant (Am J Surg Pathol 2002;26:932)
● Myoid differentiation in fibrosarcomatous DFSP (Acta Dermatovenerol Alp Panonica Adriat 2006;15:39)
● Sclerosing variant (Int J Dermatol 2006;45:59)

Treatment
=========================================================================

● Imatinib therapy (tyrosine kinase inhibitor) is gold standard for treatment of inoperable or recurrent DFSP (Sarcoma 2011;2011:959132)
● Must excise subcutaneous fat (wide local excision with 2-3 cm margins) to prevent recurrence (Plast Reconstr Surg 2007;119:1779)
● Three dimensional histologic evaluation of margins recommended (Ann Surg Oncol 2004;11:438)
● Imatinib may be effective in CD117 negative tumors (J Clin Oncol 2005;23:866)

Clinical images
=========================================================================



Papulonodular thigh lesions


Before and after Imatinib treatment

Gross description
=========================================================================

● Nodular, polypoid or plaque-like, centered in dermis, can occur in deep soft tissue
● Mean 5 cm, gray-white (brown/black if melanocytes present), may appear circumscribed
● Hemorrhage and necrosis are rare

Micro description
=========================================================================

● Non circumscribed, highly cellular, “tight” storiform pattern (cells radiating in spokes at right angles around a central point that often contains a vessel) that infiltrates deeply into subcutaneous tissue and entraps fat cells to form characteristic honeycomb pattern
● Some tumors show areas of fascicular growth
● Storiform pattern may be absent in early plaque stage
● Cells are monomorphic, thin and spindly with scant eosinophilic cytoplasm and hyperchromatic nuclei resembling neurofibroma
● May have numerous mitotic figures, but not atypical ones
● Collagen usually non-polarizable and thin
● Only mild pleomorphism and focal atypia
● May coexist with giant cell fibroblastoma
● Usually no significant pleomorphism, no/rare histiocytes, no histiocyte-like cells, no foam cells, no giant cells or other inflammatory cells

Variants:
● Atrophic (depressed lesion), collagenous (with central thick collagen bundles), granular cell (S100 negative), myxoid (see below), palisading, pigmented, sclerosing

Micro images
=========================================================================



Small uniform cells radiating like pinwheels from central area that often has a blood vessel is characteristic


Uniform cells with no significant pleomorphism, minimal intercellular collagen,
no/rare foam cells or giant cells, which are characteristic of benign fibrous histiocytoma



Fine strands of collagen are present

       
Infiltration of fat causes tumor cells to surround fat cells


Residual fat cells are in linear arrangement resembling a string of pearls,
which is characteristic of DFSP but not benign fibrous histiocytoma



DFSP with diminished storiform pattern but CD34+ (not shown)


Pigmented cells are not common


Variants: with fibrosarcomatous component, myxoid, pigmented

Cytology
=========================================================================

● Homogeneous with isolated spindle cells, often tissue fragments with storiform pattern, fibrillary stromal fragments, naked nuclei
● Occasional slight to moderate atypia (Diagn Cytopathol 2004;30:261)

Positive stains
=========================================================================

● CD34 (strong in 95%), vimentin
● Also actin (focal), ApoD (Am J Surg Pathol 2004;28:1063)
● bcl2, NKI-C3 (Am J Clin Pathol 1992;97:478)
● CD99 (J Cutan Pathol 2008;35:647)

Negative stains
=========================================================================

● Factor XIIIa (usually), keratin, EMA, S100, HMB45, desmin, CD117 (J Cutan Pathol 2007;34:857)

Electron microscopy description
=========================================================================

● Stellate or spindle cells with long, slender, ramified cell processes joined by primitive junctions, often with subplasmalemmal densities
● Commonly multivesicular buds (Ultrastruct Pathol 2006;30:283)

Molecular/cytogenetics
=========================================================================

● t(17,22)(q21;q13) [collagen type 1 alpha 1 gene and platelet derived growth factor beta chain gene, OMIM #607907] found in almost all cases using multiplex RT-PCR (Hum Path 2008;39:184)
● Also supernumerary ring chromosomes derived from t(17;22) (Oncogene 2001;20:2965)
● Rarely other translocations (Virchows Arch 2008;452:689)

Differential diagnosis
=========================================================================

● Dermatofibroma: also storiform but non-infiltrative, less cellular than DFSP, Factor XIIIa positive, CD34 negative
● Thymoma: storiform but different location, CD34 negative
● MFH-pleomorphic or atypical fibroxanthoma: storiform pattern but also moderate/marked pleomorphism and nuclear atypia


Indeterminate lesions between DFSP and dermatofibroma

General
=========================================================================

● Report of 10 tumors with features of both tumors, all Factor XIIIa+, CD34+, although in different cells (Am J Surg Pathol 2000;24:996)
● Clinically, one recurrence at mean 22 months follow-up
● Recommend complete excision
● Cytogenetics may help distinguish


Myxoid variant of DFSP

General
=========================================================================

● DFSP with 50%+ myxoid stroma
● Uncommon
● Median age 40 years, male and female
● Extremities, head and neck, trunk, anogenital region
● Associated with recurrent tumor
● Similar prognosis as classic DFSP (Am J Surg Pathol 2007;31:1371)
● Should distinguish from post-traumatic CD34+ myxoid dermatofibrohistiocytoma (J Cutan Pathol 2009;36:84)

Case reports
=========================================================================

● 54 year old woman with supraclavicular mass (Case of the Week #132)

Treatment
=========================================================================

● Complete excision
● Occasional recurrences (Am J Dermatopathol 2007;29:443)

Gross description
=========================================================================

● Median 3 cm, white-tan-gray-yellow, firm to gelatinous

Micro description
=========================================================================

● Infiltrative, often hypocellular, sheet-like, bland spindle cells with pale eosinophilic cytoplasm, spindled nuclei, no pleomorphism
● Stroma is myxoid with prominent thin walled vessels
● Diffuse infiltration of fat
● Also cellular areas typical of DFSP

Micro images
=========================================================================


               
Case of the week

Virtual slides
=========================================================================



Myxoid DFSP

Positive stains
=========================================================================

● CD34

Negative stains
=========================================================================

● S100, muscle markers, CD99

Differential diagnosis
=========================================================================

● Myxoid neurofibroma: wavy nuclei, often intratumoral axons, strong S100+
● Superficial angiomyxoma: myxoid stroma with numerous small vessels, may be CD34+, but does not infiltrate fat, tends to be less cellular
● Myxoid liposarcoma: vessels are more abundant, delicate and branching, lipoblasts are prominent


Sarcomas arising in DFSP

General
=========================================================================

● Usually resembles fibrosarcoma, rarely MFH-pleomorphic
● Good prognosis (Clin Sarcoma Res 2012;2:4); in cases with wide local excision and negative margins, 20% recur, metastatic rate varies from 0% (Am J Surg Pathol 2000;24:1125), to 10% (Am J Surg Pathol 2006;30:436)
● Report as “DFSP with areas of fibrosarcoma”, indicate extent of fibrosarcomatous change, nuclear grade, level of mitotic activity

Case reports
=========================================================================

● 28 year old woman with rapidly growing facial lesion (Head Neck Oncol 2011 Feb 4;3:5)
● 42 year old woman with abdominal mass (Arch Pathol Lab Med 2006;130:882)

Treatment
=========================================================================

● Wide local excision

Micro description
=========================================================================

● In fibrosarcomatous areas, spindle cells intersect at acute angles, chromatin is coarser than usual, increased mitotic activity

Micro images
=========================================================================


Fibrosarcoma arising in DFSP:
       
DFSP cells trap fat cells, fibrosarcoma cells are more uniform

   
Fibrosarcoma cells are spindled, uniform and hyperchromatic and arranged in herringbone pattern


Uncommon finding is myoid nodules containing cells with eosinophilic cytoplasm, present in DFSP
or fibrosarcomatous areas, cells are actin+, CD34-, desmin-



H&E and FISH


Mitotic activity

Pleomorphic sarcoma arising in DFSP:

Tumor cells are pleomorphic and have granular chromatin



Fibroblastic / myofibroblastic tumors

Desmoplastic fibroblastoma


Reviewer: Komal Arora, M.D. (see Reviewers page)
Revised: 19 July 2012, last major update July 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.

General
=========================================================================

● Fibroblastic lesion centered in subcutaneous tissue with reactive fibroblasts, low cellularity and abundant collagen (Hum Pathol 1998;29:676)
● Also called collagenous fibroma

Sites:
● Usually upper extremities, back, feet

Epidemiology
=========================================================================

● Rare benign lesion of adult men (70% between ages 40 and 69 years)

Case reports
=========================================================================

● 41 year old woman with thigh mass (J Cutan Pathol 2008;35 Suppl 1:70)

Treatment
=========================================================================

● Conservative excision, does not recur or metastasize

Gross description
=========================================================================

● Usually 1-4 cm, well circumscribed, may be lobulated, has firm and homogeneous gray cut surface resembling cartilage

Gross images
=========================================================================


Well circumscribed tumor

Micro description
=========================================================================

● Paucicellular, bland spindled (stellate) and reactive appearing fibroblasts and myofibroblasts separated by abundant collagen with variable myxoid stroma
● Fibroblasts have amphophilic cytoplasm, vesicular nuclei and distinct nucleoli
● 70% of cases involve subcutis, 25% extend into skeletal muscle

Micro images
=========================================================================



Large, reactive appearing spindled fibroblasts in fibrous matrix


Focus of low cellularity and dense collagen


More cellular area with reactive type fibroblasts


Scattered stellate cells in hypovascular collagenous matrix;


Hypocellular lesion with pseudocapsule and sparse cells separated by abundant collagen


Spindle cells with long nuclei in dense collagenous stroma;


Vimentin+


Most cells are negative for smooth muscle actin

Positive stains
=========================================================================

● Vimentin, variable alpha smooth muscle actin

Negative stains
=========================================================================

● Desmin, EMA, S100, CD34

Electron microscopy description
=========================================================================

● May have fibronexus junctions-markers of myofibroblastic differentiation (Ultrastruct Pathol 2004;28:149)

Molecular
=========================================================================

● t(2;11)(q31;q12) or 11q12 abnormalities observed rarely (Cancer Genet Cytogenet 2004;149:161, Cancer Genet 2011;204:569, Histopathology 2007;51:859, Cancer Genet Cytogenet 2009;192:73)

Differential diagnosis
=========================================================================

Fibromatosis: not circumscribed, more cellular, fascicular pattern, prominent vasculature (Adv Anat Pathol 1999;6:275)

Additional references
=========================================================================

Am J Surg Pathol 1995;19:1077, APMIS 2002;110:283, Stanford University



Fibroblastic / myofibroblastic tumors

Elastofibroma


Reviewer: Komal Arora, M.D. (see Reviewers page)
Revised: 19 July 2012, last major update July 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.

General
=========================================================================

● Benign, poorly circumscribed pseudotumor of subscapular region, composed of collagen and coarse enlarged elastic fibers
● Reactive hyperplasia involving abnormal elastogenesis
● Also called elastofibroma dorsi
● First described in 1961 by Jarvi and Saxen (Acta Pathol Microbiol Scand 1961;51:83)

Sites:
● More common on apex of scapula, usually right sided
● Occasionally in deltoid muscle, infraolecranon area, hip, thigh, stomach
● May be multiple, bilateral or familial
● May be periosteal in origin
● Slightly different amino acids from elastin
● Has collagen types I-III (type II normally restricted to articular cartilage and ocular structures)

Epidemiology
=========================================================================

● Usually age 55+ years
● Associated with hard manual labor
● Related changes found at autopsy in 13-17% of elderly
● More common in women

Case reports
=========================================================================

● 55 year old woman (Case of the Week # 46)
● 69 year old man with tumor of hand (J Bone Joint Surg Br 1987;69:468)
● 69 year old woman with bilateral subscapular tumors and tumor surrounding a stomach ulcer (Am J Surg Pathol 1985;9:233)
● 78 year old man with multiple subcutaneous nodules (J Am Acad Dermatol 2004;50:126)

Treatment
=========================================================================

● Excise if symptomatic, does not recur

Clinical images
=========================================================================



Shoulder based tumors


Typical location (arrow)

Gross description
=========================================================================

● Ill defined, rubbery, gray-white fibrous tissue mixed with yellow streaks of elastin
● Up to 15 cm

Gross images
=========================================================================



Fibrocollagenous areas blend with fat (AFIP)

   
Poorly defined fibroelastic tumor entrapping fat


Gray-white fibrous tissue mixed with fat

Micro description
=========================================================================

● Collagen bundles alternate with large, thick eosinophilic elastic cylinders with a dense central core, elastic fibers may be fragmented into linear globules (beads on a string)
● Often has irregular interdigitation into adipose tissue

Micro images
=========================================================================



Paucicellular fibrous tissue mixed with fat


Thick, densely eosinophilic elastin bands are mixed with collagen


Elastin bands have serrated edges and are associated with detached globular elastin arranged like beads on a string


Thick bands of fibrous tissue (long arrows) intermixed with multiple regions of mature adipose tissue


Fibrous tissue mixed with elastin bands


Branched (arrow) and unbranched coarse elastin fibers mixed with collagen and adipose


H&E and elastic stain

           
Verhoeff elastin stain highlights elastin fibers and the bead-like arrangement of the elastin globules


Orcein (elastin) stain

           

       
Case of the Week #46

Cytology
=========================================================================

● Hypocellular smear with diagnostic aggregates of globules within a collagenous matrix (Diagn Cytopathol 2011 May 31 [Epub ahead of print], Acta Cytol. 2007;51:497, Anticancer Res 2002;22:3561)
● Altered elastic fibers have green-yellow autofluorescence with ultraviolet light (Diagn Cytopathol 2002;26:310)

Positive stains
=========================================================================

● Vimentin, elastic stains (fibers have dense core and irregular margins), CD34 in spindle cells (Virchows Arch 2006;448:195)

Negative stains
=========================================================================

● S100, desmin, smooth muscle actin, p53 (Ann Diagn Path 2002;6:94)

Electron microscopy description
=========================================================================

● Cylinders composed of immature amorphous elastic tissue, central core contains mature fibers, removed by elastase digestion (J Electron Microsc (Tokyo) 2006;55:89, Med Mol Morphol 2008;41:179)

Molecular
=========================================================================

● Xq12-q22 or #19 gains in 30% (Int J Mol Med 2002;10:277)

Differential diagnosis
=========================================================================

Nuchal fibroma: younger than 55 years, between scapula and vertebrae, dense collagen but no elastic fibers
Fibrolipoma: no elastic fibers
Desmoid fibromatosis: more cellular, infiltrates skeletal muscle, no elastic fibers

Additional references
=========================================================================

World J Surg Oncol 2007;5:15, Sarcoma 2008;2008:756565, APMIS 2007;115:115, Ann Thorac Surg 2007;83:1894
eMedicine, Stanford University



Fibroblastic / myofibroblastic tumors

Eosinophilic fasciitis


Reviewer: Komal Arora, M.D. (see Reviewers page)
Revised: 20 July 2012, last major update July 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.

General
=========================================================================

● Rare fibrosing disorder with scleroderma-like induration of distal extremities
● Diffuse fasciitis with fibrosis, eosinophilia and inflammation of skin, subcutaneous tissue and fascia
● Not a WHO diagnosis
● First described by Shulman (Trans Assoc Am Physicians 1975;88:70) [also called Shulman’s syndrome]

Epidemiology
=========================================================================

● Mean age 50 years, 75% women
● Eosinophilic-myalgia syndrome is different, and is associated with contaminated L-tryptophan, myalgia and neuritis (Hum Pathol 1992;23:429)
● Shulman's syndrome tends to involve the subcutis alone and the eosinophilia-myalgia syndrome tends to be a pancutaneous-subcutaneous process (eMedicine, J Am Acad Dermatol 1992;26:95)
● Presence of morphea-like skin lesions is associated with residual fibrosis (Clin Rheumatol 2007;26:1445)

Case reports
=========================================================================

● 76 year old woman (Dermatol Online J 2003;9:33)
● Paraneoplastic phenomenon associated with metastatic colorectal carcinoma (Australas J Dermatol 2008;49:27)

Treatment
=========================================================================

● High dose corticosteroids (Int J Dermatol 2008;47:29)

Clinical images
=========================================================================



Symmetric, thick, sclerotic skin with subtle yellow-orange hue on forearms and upper arms

Gross description
=========================================================================

● Woody, firm subcutaneous mass

Micro description
=========================================================================

● Eosinophils, lymphocytes, mast cells and histiocytes in fibrotic or fibromyxoid stroma of subcutis and fascia

Micro images
=========================================================================


           
Thickening of fascia with chronic inflammatory infiltrate


Inflammatory infiltrate in deep subcutis

Additional references
=========================================================================

eMedicine #1, #2



Fibroblastic / myofibroblastic tumors

Fibroma of tendon sheath


Reviewer: Komal Arora, M.D. (see Reviewers page)
Revised: 20 July 2012, last major update July 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.

General
=========================================================================

● Well circumscribed, lobulated fibrous tumor attached to tendon or tendon sheath
● Also called tenosynovial fibroma
● Benign, uncommon
● May overlap with nodular fasciitis (Am J Surg Pathol 1989;13:472) or giant cell tumor of tendon sheath (Mod Pathol 1995;8:155, Histopathology 1992;20:213)

Epidemiology
=========================================================================

● 60% men, ages 30-50 years old with nodule on fingers, hands or wrist

Case reports
=========================================================================

● Tumors of palmar flexor sheath (Internet Journal of Hand Surgery 2008;2(1))
● Medial canthus of eye (Ophthal Plast Reconstr Surg 2007;23:341)
● Multiple fibromas of tendon sheath (Ann Dermatol 2011;23:S45)

Treatment
=========================================================================

● Excise to relieve symptoms but preserve function, may be difficult to remove from adherent tendons
● Benign, but up to 24% recur; does not metastasize

Clinical images
=========================================================================



Multiple non-movable deep seated nodules on palm

Gross description
=========================================================================

● Well circumscribed, small fibrous multinodular mass < 3 cm, cut surface is pale, solid and homogeneous

Micro description
=========================================================================

● Well circumscribed nodules of dense fibrous tissue with occasional spindle or stellate mesenchymal cells in S or C shaped patterns
● Cells have scant cytoplasm and elongate nuclei with evenly distributed fine chromatin
● Often dilated or slit-like channels / clefts resembling tenosynovial spaces
● Varies from cellular to paucicellular
● May have bizarre tumor cells, extravasated red blood cells, but no atypical mitotic figures, no necrosis, no hyperchromasia

Micro images
=========================================================================



Multinodular proliferation


Extensive collagenization of nodules produces this typical, eosinophilic, paucicellular
appearance, incomplete separation of the nodules produces cleft-like spaces



Most cases are paucicellular with scattered spindled fibroblasts in a densely collagenized matrix and scattered small vessels


Transition from collagenous to cellular area


Cellular area resembles leiomyosarcoma or fibrosarcoma, but these tumors are rare in hands and feet


Fibroblasts are bland (ruling out sarcoma) and separated by collagen


Predominately acellular fibrous tissue with areas of hyalinization and characteristic slit-like vascular channels

   
Spindle shaped fibroblasts in collagenous stroma with slit like vascular channels

Cytology images
=========================================================================


   
Loose cohesive clusters of bland appearing spindle shaped cells with variable cytoplasm and oval/elongated nuclei and hyalinized collagenous fragments

Electron microscopy description
=========================================================================

● Resembles myofibroblasts and fibroblasts

Electron microscopy images
=========================================================================



Spindle cells in collagenous matrix (M) have oval and convoluted nuclei (N),
clefts (C) are present between cells and nuclei



Spindle cell has a convoluted nucleus (N), rough endoplasmic reticulum (RER),
vacuoles (V) and thin band of myofilaments just beneath the plasma membrane (arrows)



Myofilament bundles (M) show periodic densities (arrows)


Spindle cell has rough endoplasmic reticulum (RER), myofilaments (M) and pinocytotic vesicles (arrows)

Positive stains
=========================================================================

● Smooth muscle actin, vimentin

Molecular
=========================================================================

● May have t(2;11)(q31-32;q12) (Histopathology 1998;32:433)

Differential diagnosis
=========================================================================

Sarcoma: rare in hands and feet, usually large masses with cellularity, marked chromatin abnormalities and abnormal mitotic figures
Benign fibrous histiocytoma: usually not hands or feet, prominent histiocyte-like cells, foam cells, giant cells and hemosiderin, CD68+
Giant cell tumor of tendon sheath: more cellular, cells have histiocyte-like nuclei, also prominent giant cells, foam cells, hemosiderin; no slit-like vascular spaces, no extensive hyalinized stroma

Additional references
=========================================================================

Stanford University



Fibroblastic / myofibroblastic tumors

Fibromatosis of soft tissue - general


Reviewer: Komal Arora, M.D. (see Reviewers page)
Revised: 20 July 2012, last major update July 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.

General
=========================================================================

● Proliferation of histologically benign appearing myofibroblasts and fibroblasts or primitive mesenchymal cells (pediatric fibromatoses) with infiltrative growth, collagenous stroma, low to moderate mitotic activity, aggressive behavior with local recurrence, but no metastases
● Divided into adult and pediatric types

Adult types:
● Includes deep (or desmoid) fibromatoses and superficial fibromatoses (described separately)
● Those that arise within and deep to fascia are called desmoid fibromatoses (also desmoid tumor or aggressive aponeurotic fibromatoses)
● Those limited to fascia and superficial soft tissue plane (palmar, plantar, penile fibromatoses and knuckle pads) are less aggressive but recur frequently

Pediatric fibromatoses:
● Includes numerous entities described separately including infantile desmoid, inclusion body (or infantile digital), myofibroma/myofibromatosis, Gardner fibroma, fibromatosis coli and others
● Often characterized by primitive mesenchymal cells in addition to myofibroblasts and fibroblasts



Fibroblastic / myofibroblastic tumors

Fibromatosis – superficial


Reviewer: Komal Arora, M.D. (see Reviewers page)
Revised: 20 July 2012, last major update July 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.

Palmar fibromatosis (Dupuytren’s contracture)

General
=========================================================================

● Nodular proliferative process of palmar aponeurosis, surrounding adipose and occasionally dermis, due to fibroblasts, myofibroblasts and fibrocytes
● Most common type of fibromatosis (1-2% of population), prevalence increases with age (24% at age 65+)

Epidemiology
=========================================================================

● 75% are men
● 50% are bilateral, 10% also have plantar disease, 1-4% have penile fibromatosis

Clinical description
=========================================================================

● Puckers overlying skin as it ages
● Causes flexion contracture of digits 4 and 5 due to cord-like expansion of digital aponeurotic slips
● Does not involve deep structures such as tendons or skeletal muscle
● May be caused by fibrogenic cytokines (J Hand Surg Br 2005;30:557)

Treatment
=========================================================================

● Observation, excision or incision of contracture band
● Often recurs

Clinical images
=========================================================================

   
Flexion contracture

Gross description
=========================================================================

● Small nodules or nodular masses associated with aponeurosis and subcutaneous fat, with gray-yellow-white cut surface (color depends on collagen content)

Micro description
=========================================================================

Proliferative phase:
● Uniform, plump, immature spindle cells (myofibroblasts and fibroblasts) with bland nuclei and indistinct nucleoli
● Moderate collagen and elongated vessels

Older lesions:
● More dense collagen, less cellularity
● Variable mitotic figures
● Occasional attachment to dermis or cartilaginous metaplasia
● Usually no infiltration of surrounding tissue beyond subcutis

Micro images
=========================================================================



Nodule of variably cellular fibroblastic tissue infiltrates an aponeurosis, with bland, uniform spindled cells in a dense hyalinized collagen stroma


Mitotic figures may be present in cellular regions but are never atypical


Various images

#1, #2, #3

Positive stains
=========================================================================

● Vimentin, variable muscle specific and smooth muscle actin (in proliferative phase)

Negative stains
=========================================================================

● Keratin, CD34

Electron microscopy description
=========================================================================

● Fibroblasts and myofibroblasts

Molecular
=========================================================================

● Near diploid, often +7 or +8, no gene amplifications or deletions (Cancer Genet Cytogenet 2008;183:6)
● Usually considered reactive not neoplastic (J Transl Med 2006;4:21)
● Aberrations in Wnt signaling pathway (N Engl J Med 2011;365:307, Plast Reconstr Surg 2012;129:921, Joint Bone Spine 2012;79:7), but no somatic mutations of beta-catenin genes unlike desmoid fibromatosis (Mod Pathol 2001;14:695)

Differential diagnosis
=========================================================================

Fibrosarcoma: single large mass of deep soft tissue with intersecting bundles of cells whose nuclei have abnormal chromatin
● Epithelioid sarcoma: common in hands, but some cells have distinctive epithelioid appearance with abundant bright eosinophilic cytoplasm, also necrosis, keratin+, CD34+
Desmoid tumors: rare in hand, dominant mass infiltrates skeletal muscle

Additional references
=========================================================================

eMedicine, Stanford University, Wikipedia
J Am Acad Orthop Surg 2011;19:746


Plantar fibromatosis (Ledderhose’s disease)

General
=========================================================================

● Nodular proliferative process of plantar aponeurosis and surrounding adipose due to fibroblasts, myofibroblasts and fibrocytes
● Heterogeneous group of conditions with plantar location, mature collagen and fibroblasts, but no malignant features (eMedicine)

Epidemiology
=========================================================================

● Common in boys < 10 years old and teenagers
● Associated with palmar and penile fibromatosis, also continuous phenobarbital treatment for epilepsy (Epilepsia 2008;49:1965)
● Usually NOT associated with contractures

Clinical description
=========================================================================

● Only 10-25% bilateral
● May be nodular
● Often presents with firm subcutaneous nodule or thickening associated with pain after standing or walking typically on the medial aspect of the sole
● Clinically resembles melanoma, synovial sarcoma, Kaposi’s sarcoma

Treatment
=========================================================================

● Observation, surgery if symptomatic, fasciectomy has fewer recurrences (25%) than local excision (100%, Plast Reconstr Surg 2008;122:486)

Clinical images
=========================================================================



Mass along medial plantar surface

   
Various images

Gross description
=========================================================================

● 2-3 cm nodules associated with aponeurosis and subcutis, with gray-yellow-white cut surface (color depends on collagen content)

Gross images
=========================================================================



Plantar nodules

Micro description
=========================================================================

Proliferative phase:
● Hypercellular collection of uniform, plump, immature spindle cells with bland nuclei and indistinct nucleoli
● Moderate collagen and elongated vessels
● Variable multinucleated giant cells (Am J Surg Pathol 2002;26:244)

Older lesions:
● Denser collagen, less cellularity
● Often prominent chronic inflammation, variable mitotic figures and hemosiderin

Positive stains
=========================================================================

● Vimentin, variable muscle specific and smooth muscle actin

Electron microscopy description
=========================================================================

● Fibroblasts and myofibroblasts

Molecular
=========================================================================

● Near diploid, often +7 or +8, no somatic mutations of beta-catenin genes unlike desmoid fibromatosis (Mod Pathol 2001;14:695)
● Reciprocal t(2;7)(p13;p13) (Cancer Genet Cytogenet 2005;158:67)

Differential diagnosis
=========================================================================

Calcifying aponeurotic fibroma: plump or epithelioid fibroblasts palisading around cartilage and spotty calcification
Desmoid fibromatosis: rare in feet, infiltrates skeletal muscle, > 3 cm, often beta-catenin+
Fibrosarcoma: single large mass of deep soft tissue with intersecting bundles of cells with abnormal chromatin, herringbone pattern
● Monophasic synovial sarcoma: uniformly hypercellular, often staghorn vascular pattern or ropy collagen


Penile fibromatosis (Peyronie’s)

General
=========================================================================

● Fibrous thickening of dermis and Buck’s fascia between corpora cavernosa and tunica albuginea, causing curvature towards side of lesion and restricting movement of these structures during erection
● Etiology may be related to Parc protein (BJU Int 2010;106:1706) or Wnt2 (J Sex Med 2012;9:1430)

Epidemiology
=========================================================================

● Typically age 40+ years, rarely age 40 or less (J Androl 2003;24:27)
● Various etiologies (microvascular trauma - Int J Impot Res 2002;14:406, urethritis, sclerosing inflammatory process, idiopathic), appears to differ from other superficial fibromatoses (Curr Urol Rep 2004;5:478) although associated with them
● Prevalence 3-9% (Int J Impot Res 2002;14:379), associated with plaques, pain, induration, deviation, palmar fibromatosis (Int J Impot Res 2011;23:142)
● Usually dorsolateral penis, 30% have inflammatory component

Case reports
=========================================================================

● With ossification (Sao Paulo Med J 2007;125:124)

Treatment
=========================================================================

● May spontaneously regress, responds to small amounts of irradiation, steroids, other intralesional injections (J Androl 2009;30:397)
● Also plaque excision and grafting, other surgery (Eur Urol 2009;55:1469, Curr Urol Rep 2011;12:444)

Micro description
=========================================================================

● Disorganization of collagen of tunica albuginea with formation of nodules, often hyalinizing fibrosis, perivascular lymphocytic infiltrate in 1/3, linear band of calcification in 1/4 (J Urol 1997;157:282)

Micro images
=========================================================================



Metaplasia of bone in corpus spongiosum

Electron microscopy description
=========================================================================

● Penile plaques are composed of collagen fibrils, amorphous particulate material and fibroblasts (Int J Urol 1997;4:274)

Differential Diagnosis
=========================================================================

● Epithelioid hemangioma: J Med Case Rep 2011;5:260
● Epithelioid sarcoma: may clinically appear similar (Int J Impot Res 2003;15:378)

Additional references
=========================================================================

Wikipedia



Fibroblastic / myofibroblastic tumors

Fibromatosis - deep (desmoid type)


Reviewer: Komal Arora, M.D. (see Reviewers page)
Revised: 20 July 2012, last major update July 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.

General
=========================================================================

● Clonal fibroblastic proliferation of deep soft tissue with infiltrative growth
● "Desmos" (Greek) means tendon-like
● Locally aggressive (local recurrence, but no metastases)
● See also description at other sites, including breast, colon, small bowel

Epidemiology
=========================================================================

● Incidence of 2-4 per million population, less common than superficial fibromatosis
● May be familial (associated with Gardner’s syndrome/FAP syndrome, Clin Gastroenterol Hepatol 2008;6:215 or familial desmoid syndrome, Am J Hum Genet 1996;59:1193) or related to trauma

Clinical features
=========================================================================

● Usually ages 15-39 years, may be painful
● Common sites in children are head and neck
● May be fatal due to local effects, particularly in head and neck
● Can be “staged” based on size, symptoms and complications (Dis Colon Rectum 2008;51:897)
● Prognostic factors: age, tumor size, tumor site (J Clin Oncol 2011;29:3553)

Abdominal fibromatosis:
● Arises within abdominal wall of women during or after pregnancy
● May see with cesarean section scar

Extraabdominal fibromatosis:
● Arises outside abdomen and abdominal wall, usually in muscles of shoulder, chest wall, back and thigh, equal gender frequencies

Intraabdominal fibromatosis:
● Mesenteric, pelvic or retroperitoneal locations, associated with Gardner’s syndrome (familial adenomatous polyposis, multiple osteomas)
● Often post-surgical

Case reports
=========================================================================

● 27 year old woman with post-traumatic paraspinal mass (World J Surg Oncol 2008;6:28)
● 29 year old women with tumor of abdominal wall (Radiology 2005;236:81, Internet J of Surg 2007;10:2)
● 30 year old man with aggressive mesenteric tumor that responded to chemotherapy (Jpn J Clin Oncol 2008;38:222)
● 43 year old woman with tumor of retroperitoneal space (World J Surg Oncol 2004;2:33)

Treatment
=========================================================================

● Excision with wide margins and possibly frozen section evaluation of margins (Ann Surg Oncol 2009;16:1642)
● Inadequate excision may cause recurrence, less recurrence in abdominal wall than elsewhere but may recur 5-6 times
● May stop growing if stop excising, some recommend watchful waiting if asymptomatic or not growing (Expert Rev Anticancer Ther 2009;9:525)
● May respond to chemotherapy (J Clin Oncol 2007;25:501), COX2 inhibitors (Urology 2007;70:591.e3), imatinib (J Cancer Res Clin Oncol 2007;133:533), NSAIDs (World J Surg Oncol 2008;6:17), radiation (Am J Clin Oncol 2005;28:211), tamoxifen or watchful waiting (Eur J Surg Oncol 2008;34:462)

Clinical images
=========================================================================


   
Swollen calf


Paraspinous subcutaneous mass


Site distribution in one study of 46 extra-abdominal desmoid tumors

Gross description
=========================================================================

● Large, firm, white cut surface, infiltrative borders
● Often in muscular fascia, cuts with gritty sensation, 5-10 cm

Gross images
=========================================================================



Extra-abdominal fibromatosis: dense white, trabeculated fibrous tissue that invades skeletal muscle and produces cross section of alternating white and red patches


Extraabdominal fibromastosis: thoracic tumor


Extraabdominal fibromastosis: firm white fusiform mass of calf

   
Abdominal fibromatosis: large tumor of anterior abdominal wall


Intraabdominal fibromatosis: retroperitoneal tumor has gray-glossy cut surface


Intraabdominal fibromatosis: mesentery of small bowel


Intraabdominal fibromatosis: retroperitoneal tumor has gray-glossy cut surface

   
Well defined margin (left-uncommon) versus infiltrative margin (right)


Desmoid fibromatosis (left) contrasted with high-grade fibrosarcoma (right);
fibromatosis has gristle-like consistency, but fibrosarcoma tends to be white, fleshy
and necrotic with an overlying tendon


Tumor infiltrates thoracic wall

Trunk tumor #1, #2

Thigh tumor

Gray-white tumor of Gardner syndrome

Micro description
=========================================================================

● Poorly circumscribed with infiltration of adjacent tissue
● Uniform cellularity between exuberant fibrous proliferation and low grade fibrosarcoma
● Cells are bipolar fibroblasts and myofibroblasts (reduced amphophilic cytoplasm that merges with surrounding collagen, open chromatin, well defined nuclear membrane, one distinct nucleolus)
● Usually more collagenous and less cellular than nodular fasciitis
● Mucopolysaccharide matrix with thin walled, curvilinear, non-branching or ectatic vessels
● Stroma varies from collagenous, keloid-like to myxoid
● Regenerative muscle cells within lesions may resemble giant cells
● Perivascular lymphocytes at edge of lesion
● Few mitotic figures, no atypia
● Post radiation: histologic changes are minimal (Hum Pathol 2012 Mar 7 [Epub ahead of print])

Micro images
=========================================================================


Extra-abdominal fibromatosis - AFIP:

Low power shows paucicellular fibrous proliferation in long fascicles, with numerous slit-like vessels characteristic of desmoid fibromatosis


Fibroblasts have spindled, dense, wavy nuclei and minimal cytoplasm


Margin shows infiltration of skeletal muscle, a common feature


Atrophic and regenerating muscle fibers at the edge of the lesion may resemble rhabdomyoblasts


Some tumors are myxoid


Cells in myxoid tumors are uniformly bland, unlike those in malignant myxoid tumors


Cellular tumor has scattered mitotic figures, none atypical


Keloid-type pattern may be observed focally in deep tumors

Extra-abdominal fibromatosis - other sources:
   
Paraspinal tumor


Thigh mass has spindle cells, dense collagenous stroma, slit-like vessels and chronic inflammation


Pre-radiation therapy


Post-radiation therapy shows reduced cellularity


Breast tumor is smooth muscle actin+

Intra-abdominal (mesenteric) fibromatosis - AFIP:

Tumor appears to be extrinsic to bowel muscularis propria, which distinguishes it from GIST


Fibromatosis is paucicellular and composed of relatively uniform, bland spindle cells


Bland, mitotically active, uniform cells in myxoid stroma


Less commonly bland spindle cells are within collagen bundles


Pelvic tumor


Trichrome stain highlights collagen in the fibromatosis and distinguishes it from overlying normal muscularis propria

Intra-abdominal fibromatosis - other sources:
   
Uniform spindle cells with moderate collagen

Abdominal fibromatosis:

Extension into adjacent muscle


Fascicles of fibroblastic spindle cells with abundant intercellular collagen


Immunostains

Cytology
=========================================================================

● Bland spindle cells with long, fusiform nuclei and metachromatic matrix material
● Tumor cells are individual or as fragments within matrix (Cancer 2007;111:166)
● FNA is fairly reliable for diagnosis but core needle biopsy is better (Acta Orthop 2006;77:926)
● May have long fascicular arrangement of spindle cells (Diagn Cytopathol 2012;40:45)

Cytology images
=========================================================================



Low power shows paucicellular fibrous proliferation in long fascicles, with numerous slit-like vessels characteristic of desmoid fibromatosis

Positive stains
=========================================================================

● Vimentin, variable smooth muscle actin and muscle specific actin, variable CD117 (Am J Surg Pathol 2002;26:1296, but depends on antibody used, Am J Surg Pathol 2001;25:549)
● Also nuclear beta-catenin (sensitive but not specific, Am J Surg Pathol 2005;29:653, Am J Surg Pathol 2002;26:1296), ER-beta (Cancer 2006;106:208, Biosci Trends 2010;4:25)

Negative stains
=========================================================================

● Keratin, S100, CD34 (J Clin Pathol 2004;57:1119)
● ALK, desmin, ER-alpha, c-Kit, PR (J Clin Pathol 2005;58:1152)

Electron microscopy description
=========================================================================

● Fibroblastic and myofibroblastic features, including intrareticular collagen fibers, thin filament bundles, cytoplasmic dense bodies

Molecular
=========================================================================

● Clonal; associated with Wnt/beta-catenin (APC-beta-catenin-Tcf) pathways
● Somatic beta-catenin point mutations in exon 3, codon 41 or codon 45 in 87% (Am J Surg Pathol 2007;31:1299)
● Also associated with trisomy 20 and 8 (Am J Path 1999;154:729, Cancer Genet Cytogenet 1995;79:139) and loss of 5q (APC gene)

Molecular images
=========================================================================


       
Trisomy 20 and 8

Differential diagnosis
=========================================================================

● Fibrosarcoma: atypia or mitotic figures present
● GIST: strong CD117+, CD34+, Am J Clin Pathol 2004;121:93)
● Idiopathic retroperitoneal fibrosis (Orman’s disease): inflammatory, strangles the ureters
● Leiomyoma: bright pink cytoplasm of smooth muscle, desmin+
● Low grade fibromyxoid sarcoma: heavily collagenized stroma with abrupt transition to myxoid areas, often epithelioid areas or poorly formed but large collagen rosettes; beta catenin negative
● Neurofibroma: no myofibroblasts, S100+
● Schwannoma: palisading Schwann cells, usually minimal collagen, S100+
● Sclerosing omentitis: grows like panniculitis, beta catenin negative



Fibroblastic / myofibroblastic

Fibromatosis colli


Reviewer: Komal Arora, M.D. (see Reviewers page)
Revised: 20 July 2012, last major update July 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.

General
=========================================================================

● Fibromatosis that appears at birth, often bilateral, affecting lower 1/3 of sternocleidomastoid muscle, causing thickened muscle
● Also called congenital torticollis (torticollis: twisting of neck causing unnatural position of head, usually caused by spasm of neck muscles, Am Fam Physician 1996;54:1965)

Epidemiology
=========================================================================

● Associated with congenital anomalies (14% have congenital dislocations of hip, also breech deliveries)
● May be due to birth injury (breech presentation, forceps)
● Uncommon (0.4% of live births), usually diagnosed by age 6 months
● Recommended to diagnose by FNA since excision usually is not required

Treatment
=========================================================================

Early - stretching and physiotherapy, resolves in 70%
● Some cases require resection of affected muscle
● Does not recur

Gross description
=========================================================================

● Tan gritty mass of muscle up to 3 cm, no hemorrhage or necrosis

Micro description
=========================================================================

● Diffuse proliferation of uniform plump fibroblasts and myofibroblasts and scar like collagen in muscle, with entrapped reactive and degenerating skeletal muscle fibers (loss of cross striations, nuclear enlargement and hypercellularity, multinucleation, atrophy)
● Surgical specimens are usually less cellular than FNA specimens because they are obtained later in time course of disease

Micro images
=========================================================================



Multinodular proliferation of acellular collagenized tissue replaces part of sternocleidomastoid muscle


Skeletal muscle fibers are trapped at advancing edge of lesion


Scattered, bland fibrocytes are widely separated by dense collagen

Cytology
=========================================================================

Early - cellular specimen with clusters or parallel arrays of bland appearing spindle cells in fibromyxoid matrix
● Also atrophic skeletal muscle in clean background, frequent muscle giant cells, bland bare nuclei and collagen (Acta Cytol 2003;47:359)
● Usually no significant inflammation (Diagn Cytopathol 2000;23:338)

Positive stains
=========================================================================

● Vimentin, actins

Differential diagnosis
=========================================================================

● Fibromatosis: no muscle fibers which are replaced by fibrous tissue except at periphery, does not typically affect sternocleidomastoid muscle
● Proliferative myositis: doesn’t affect this site, stroma resembles granulation tissue and is not collagenous
● Fibrodysplasia ossificans progressiva: doesn’t affect this site, hand malformations are present, bone is present



Fibroblastic / myofibroblastic tumors

Fibrosarcoma of soft tissue - adult


Reviewer: Komal Arora, M.D. (see Reviewers page)
Revised: 20 July 2012, last major update July 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.

General
=========================================================================

● Malignant tumor of fibroblasts with herringbone architecture and variable collagen
● Rare (up to 3% of adult sarcomas)
● Some limit diagnosis to those age 10+ years, most patients are ages 40-55 years
● Many cases formerly called fibrosarcoma are actually dedifferentiated liposarcoma, fibromatosis, fibrosarcomatous DFSP, low-grade fibromyxoid sarcoma, MPNST, synovial sarcoma or MFH-pleomorphic
● Usually deep soft tissue of lower extremities or trunk, only rarely in retroperitoneum or mediastinum
● 50% recur, 25% metastasize (lung, bone)
● More metastases if more cellular and higher mitotic activity

Survival:
● 5 year-41%, 10 year-29%
● Better if tumor is superficial and better differentiated, low mitotic rate, no necrosis

● See also peripheral ameloblastic fibrosarcoma, sclerosing epithelioid fibrosarcoma

Treatment
=========================================================================

● Radical excision, radiation if residual tumor or positive margins
● Possibly chemotherapy if high grade

Gross description
=========================================================================

● May appear well circumscribed but nonencapsulated
● Fleshy, hemorrhagic, necrotic, white-tan

Gross images
=========================================================================



Desmoid fibromatosis (left) is contrasted with high-grade fibrosarcoma (right), fibromatosis has gristle-like consistency, but fibrosarcoma tends to be white, fleshy and necrotic with an overlying tendon

Micro description
=========================================================================

● Highly cellular fibroblastic proliferation in herringbone pattern (cells in columns of short parallel lines with all the lines in one column sloping one way and lines in adjacent columns sloping the other way)
● Cells have scant cytoplasm, tapering elongated dark nuclei with increased granular chromatin, variable nucleoli
● Mitotic activity present, often with abnormal forms
● Variable collagen
● Usually no giant cells
● No pleomorphism (or call pleomorphic MFH), no other distinct cell types

Patterns:
● Keloid-like (thick hyalinized collagen fibers), loose fascicular, focally myxoid

Micro images
=========================================================================



Herringbone pattern


Atypical uniform cells in herringbone pattern


Cells are clearly malignant, with coarse chromatin but minimal pleomorphism

   
Grade I tumor has minimal pleomorphism and low mitotic index, but is more cellular than fibromatosis

   
Grade II tumor has intermediate features

   
Grade III tumor has high grade atypia and high mitotic index

Virtual slides
=========================================================================



Fibrosarcoma

Positive stains
=========================================================================

● Reticulin stain demonstrates fibers surrounding each cell
● Phosphotungstic acid-hematoxylin demonstrates abundant cytoplasmic fibrils
● Also vimentin, type 1 collagen, p53
● High Ki-67
● May be CD34+ if arises from DFSP or solitary fibrous tumor

Negative stains
=========================================================================

● S100, keratin
● Smooth muscle markers, histiocytic markers, basal lamina

Electron microscopy description
=========================================================================

● Fibroblasts with prominent rough endoplasmic reticulum but no myofilaments, no external lamina, no intercellular junction
● No distinct myofibroblasts (if present, call myofibrosarcoma)

Molecular
=========================================================================

● Aneuploid

Differential diagnosis
=========================================================================

Other tumors with fibrosarcomatous areas:
● Dedifferentiated liposarcoma
● Fibromatosis: less cellular, less hyperchromasia, no atypia, < 1 mitotic figure/HPF
● Low grade fibromyxoid sarcoma
● MFH-pleomorphic
● MPNST
● Synovial sarcoma

Additional references
=========================================================================

eMedicine



Fibroblastic / myofibroblastic tumors

Fibrosarcoma of soft tissue - infantile


Reviewer: Komal Arora, M.D. (see Reviewers page)
Revised: 20 July 2012, last major update July 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.

General
=========================================================================

● Resembles adult fibrosarcoma morphologically, but better prognosis
● Age cutoff between infantile and adult forms usually varies between 5 and 10 years

Epidemiology
=========================================================================

● Usually presents before age 2 years in axial regions or extremities with vary rapid growth
● Related to congenital mesoblastic nephroma, which has same translocation

Clinical description
=========================================================================

● 40-50% recur, but only rarely metastasizes
● Survival is 90%+

Case reports
=========================================================================

● Premature newborn with large facial mass (Arch Pathol Lab Med 2003;127:e281)
● Patient with shoulder mass clinically diagnosed as benign vascular lesion (Cutis 2012;89:61)

Treatment
=========================================================================

● Surgery and chemotherapy (J Pediatr Hematol Oncol 2002;24:722, Pediatr Blood Cancer 2009;53:23)

Gross description
=========================================================================

● May exceed 30 cm (grotesquely large compared to size of child) with tense erythematous and ulcerated overlying skin
● Firm to soft cut surface is fleshy, gray-tan with myxoid change, cystic degeneration, hemorrhage and necrosis

Gross images
=========================================================================



Fleshy white mass similar to adult fibrosarcoma

Micro description
=========================================================================

● Poorly circumscribed, lobulated mass of small to large spindled cells in fascicles or herringbone pattern with high cellularity, nuclear atypia and pleomorphism
● Increased mitotic figures, hemorrhage and necrosis
● Resembles adult fibrosarcoma
● May have prominent hemangiopericytoma-like areas, dystrophic calcification, extramedullary hematopoiesis
● Infiltrates adjacent soft tissue with irregular margins

Micro images
=========================================================================



Biphasic pattern with fibroblastic and cellular myxoid areas


High power of myxoid area


Infiltration of fat


Infiltration of muscle


Spindle cells


Plump cells have granular chromatin

   
Less cellular tumor which overlaps with infantile fibromatosis, although it almost never metastasizes


Areas of variable cellularity

   
Tumor with features of infantile fibrosarcoma and congenital mesoblastic nephroma

Leg tumor #1, #2, #3

Positive stains
=========================================================================

● Vimentin
● Variable focal smooth muscle actin, desmin, S100 and CD34

Electron microscopy description
=========================================================================

● Fibroblastic and myofibroblastic features

Molecular
=========================================================================

● 70% have t(12;15)(p13;q26), causes ETV6-NTRK3 gene fusion transcript (ETS variant gene 6 and neurotrophic tyrosine receptor kinase type 3) detectable by FISH (Mod Pathol 2001;14:1246) or RT-PCR (Am J Surg Pathol 2000;24:937, Am J Clin Pathol 2001;115:348)
● Similar translocation also present in secretory breast carcinoma (Mod Pathol 2009;22:291)
● Also trisomy 8, 11, 17 and 20

Molecular images
=========================================================================



Ideogram of fusion transcript and FISH

Differential diagnosis
=========================================================================

Adult type fibrosarcoma: usually age 10+, no t(12;15)
● Infantile fibromatosis: no pleomorphism, no mitotic figures, no t(12;15)
● Myofibromatosis: myofibroblastic features, no t(12;15) (Pediatr Dev Pathol 2008;11:355)

Additional references
=========================================================================

Stanford University



Fibroblastic / myofibroblastic tumors

Fibrous hamartoma of infancy


Reviewers: Komal Arora, M.D., Vijay Shankar, M.D. (see Reviewers page)
Revised: 15 March 2013, last major update July 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.

General
=========================================================================

● Tumor-like condition in newborns to 2 year olds
● Poorly circumscribed proliferation of immature spindle cells in organoid pattern with fat and dense fibrocollagenous tissue

Epidemiology
=========================================================================

● Rare; usually age 2 years or less (25% discovered at birth), does not occur after puberty, 2/3 male
● Usually boys

Sites
=========================================================================

● Axilla, shoulder and inguinal region (J Urol 1994;152:990)
● Not hands and feet
● Solitary, rapidly growing, freely movable mass of subcutis or dermis

Case reports
=========================================================================

● 6 month old girl with arm mass (Univ Oklahoma)
● 6 month old girl with multiple nodules with overlying hypertrichosis (J Dermatol 2006;33:427)
● 6 month old boy with recurrent tumor (Pediatr Surg Int 2005;21:119)
● 11 month old boy with thigh mass (Internet J of Dermatol 2001;1(2)
● 4 year old boy with gluteal tumor (Gulf J Oncolog 2010;1:52)
● 10 year old boy with progressively enlarging tumor on face (Acta Derm Venereol 2005;85:276)
● Giant tumors (J Am Acad Dermatol 2011;64:579)

Treatment
=========================================================================

● Benign, although may recur locally
● Excision, need not be aggressive as recurrence is uncommon (J Am Acad Dermatol 2006;54:800, J Korean Surg Soc 2011;81:61)

Clinical images
=========================================================================



Axillary tumor in 6 month old Nigerian boy


Scapular tumor in 7 year old Nigerian girl


Scapular tumor in 7 year old Nigerian girl, at surgery showing well developed capsule

Gross description
=========================================================================

● Poorly circumscribed, gray-white with yellow fat, usually 5 cm or less

Micro description
=========================================================================

● Poorly circumscribed, organoid with 3 components:
(1) trabecular or stellate immature mesenchymal cells with scant cytoplasm and bland straight or wavy nuclei in myxoid matrix
(2) fibrocollagenous tissue composed of bland fibroblasts or myofibroblasts
(3) mature fat; overlying epidermis usually has eccrine changes, including hyperplasia, duct dilation, intraluminal papillary formations and squamous syringometaplasia (J Cutan Pathol 2007;34:39)
● No/scant mitotic figures

Micro images
=========================================================================



Triphasic pattern of fibrous spindle cells delimiting islands of mature fat and primitive spindle cells


Primitive spindle cells may infiltrate fat


Primitive spindle cells and fibrous spindle cells are bland and uniform with no/rare mitotic figures

   
Three cell types

           

           
Various images

Cytology
=========================================================================

● Moderate cellularity, adipose tissue fragments, clusters of fibroblastic cells, myxoid and collagenous matrix
● No mitotic figures, no atypia (Diagn Cytopathol 2003;28:272, Acta Cytol 2008;52:201)

Positive stains
=========================================================================

● Vimentin (fibrous and mesenchyme areas)
● Spindle cells in fibrous trabeculae may be actin+, desmin+

Negative stains
=========================================================================

● Beta-catenin (Pediatr Dev Pathol 2009;12:292)

Electron microscopy description
=========================================================================

● Fibrous trabeculae are composed of fibroblasts and myofibroblasts, primitive mesenchymal cells have slender cytoplasmic processes with few organelles

Cytogenetics
=========================================================================

● Rarely complex translocations (Cancer Genet Cytogenet 2006;171:115, Cancer Genet Cytogenet 2010;201:66)
● Rarely t(2;3) (Arch Pathol Lab Med 2005;129:520)

Differential diagnosis
=========================================================================

Calcifying aponeurotic fibroma: almost always hands or feet, prominent calcification, no primitive cells within myxoid stroma
● Myofibroma: prominent hemangiopericytoma-like pattern, usually no fat

Additional references
=========================================================================

Stanford University



Fibroblastic / myofibroblastic tumors

Focal myositis


Reviewer: Komal Arora, M.D. (see Reviewers page)
Revised: 20 July 2012, last major update July 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.

General
=========================================================================

● Inflammatory condition of skeletal muscle with degeneration and regeneration, inflammatory cells and fibrosis
● Not a WHO diagnosis

Epidemiology
=========================================================================

● Mean age 41 years, range 7-94 years

Clinical description
=========================================================================

● Usually healthy patients with no history of trauma
● Evolves over weeks to a localized, painful soft tissue swelling, usually of lower extremity
● Solitary, self-limited, may be related to denervation
● May be due to statins (Int J Cardiol 2009;133:e33, Cleve Clin J Med 2011;78:393)

Case reports
=========================================================================

● 16 year old girl (J R Coll Surg Edinb 2000;45:339)
● 27 year old man post bCG vaccination (Rheumatology (Oxford) 2002;41:1074)
● 32 year old pregnant woman (Rheumatology (Oxford) 2000;39:211)
● 36 year old man with recurrent disease of peroneal muscles (Rheumatology (Oxford) 2002;41:1318)
● 43 year old man with Lyme disease (Arthritis Rheum 2006;54:2697)

Treatment
=========================================================================

● Usually none; spontaneously regresses

Gross description
=========================================================================

● Pale, ill-defined
● Mean 4 cm, range 1 to 20 cm

Micro description
=========================================================================

● Degeneration and regeneration of muscle fibers associated with interstitial inflammation and fibrosis
● Also focal neurogenic changes
● Occasionally prominent eosinophils
● Markedly inflamed cases have B cells or CD123+ dendritic plasma cells

Micro images
=========================================================================



Focal perivascular chronic inflammatory infiltrate

   
Post BCG vaccination

           
Various images

Cytology
=========================================================================

● Inflammatory cells, skeletal muscle fibers with degenerative and regenerative changes, fibrous tissue (Acta Cytol 2005;49:653)

Positive stains
=========================================================================

● CD163+ macrophages
● Lymphocytes are CD3+ and CD4+

Negative stains
=========================================================================

● Macrophages are S100- and CD1a-
● Lymphocytes are negative for TIA1, granzymeB, EBV and ALK1 (Am J Surg Pathol 2009;33:1016)

Molecular
=========================================================================

● No B or T cell rearrangement

Differential diagnosis
=========================================================================

● Poliomyelitis



Fibroblastic / myofibroblastic tumors

Gardner type fibroma


Reviewer: Komal Arora, M.D. (see Reviewers page)
Revised: 20 July 2012, last major update July 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.

General
=========================================================================

● Benign soft tissue lesion with thick, haphazard collagen and bland fibroblasts that entrap adjacent tissue
● 90% associated with FAP / Gardner’s syndrome / APC germline mutation
● Uncommon
● Affects infants, children and teenagers
● May be initial diagnostic clue to Gardner’s syndrome and APC mutations (Am J Surg Pathol 2001;25:645)
● 45% develop desmoid-type fibromatosis
● Similar histology to nuchal-type fibroma (Pathol Int 2004;54:523, Am J Surg Pathol 2000;24:1563)

Sites:
● Superficial or deep soft tissue
● Various sites

Case reports
=========================================================================

● Post-surgical desmoid tumor in Gardner’s syndrome patient (J Neurooncol 2009;91:107)

Gross description
=========================================================================

● 1-10 cm, poorly circumscribed, firm, rubbery, plaque-like, white to tan-pink cut surface with trapped fat in yellow areas

Micro description
=========================================================================

● Thick, haphazardly arranged collagen bundles, hypocellular bland fibroblasts, small blood vessels, plaque-like growth pattern with infiltration of adjacent structures

Micro images
=========================================================================



Gardner's Fibroma / Nuchal fibroma


Gardner associated fibromas and severe polyposis in 4 year old with FAP

Positive stains
=========================================================================

● CD34, cyclin D1, vimentin, nuclear beta-catenin (64%)

Negative stains
=========================================================================

● Muscle specific actin, smooth muscle actin, desmin, ER, PR

Additional references
=========================================================================

Am J Surg Pathol 2007;31:410, Pathologe 2010;31:97, Stanford University



Fibroblastic / myofibroblastic tumors

Giant cell angiofibroma


Reviewer: Komal Arora, M.D. (see Reviewers page)
Revised: 20 July 2012, last major update July 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.

General
=========================================================================

● Uncommon benign neoplasm of multinucleated giant cells and ectatic vascular spaces
● May be related to solitary fibrous tumor (Am J Surg Pathol 2000;24:971, Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009;107:685, Ophthal Plast Reconstr Surg 2008;24:325)

Epidemiology
=========================================================================

● Median age 45 years
● More common in men in eyelid/orbital sites, more common in women elsewhere
● Often slow growing painful mass

Case reports
=========================================================================

● 25 year old woman with giant cell angiofibroma of parapharyngeal space (Int J Oral Maxillofac Surg 2010;39:1024)
● 44 year old man with buccal mucosa tumor (Med Oral Patol Oral Cir Bucal 2008;13:E540)
● 50 year old woman with inguinal tumor (Ann Diagn Pathol 2000;4:240)
● 57 year old woman with eyelid tumor extending into orbit (Can J Ophthalmol 2006;41:216)

Treatment
=========================================================================

● Excision, does not recur

Sites
=========================================================================

● Eyelid, nasolacrimal duct (Ophthal Plast Reconstr Surg 2001;17:202)
● Lacrimal sac or orbit (Am J Surg Pathol 1995;19:1286, Hum Pathol 2011;42:120)

Gross description
=========================================================================

● Well-circumscribed with variable capsule, median 3 cm (larger in extra-orbital regions), may have hemorrhagic or cystic cut surface

Micro description
=========================================================================

● Cellular areas with bland round to spindle cells in myxocollagenous stroma with small-medium thick walled vessels and multinucleated giant stromal cells that line ectatic vascular spaces

Micro images
=========================================================================


   
Various images

Oral cavity tumor

Positive stains
=========================================================================

● CD34, CD99, vimentin, variable bcl2

Negative stains
=========================================================================

● CD31, CD68, c-kit/CD117, muscle specific actin, S100, desmin

Cytogenetics
=========================================================================

● Rarely t(12;17)(q15;q23) (Cancer Genet Cytogenet 2006;165:157)
● Rarely 6q13 abnormalities (Cancer Genet Cytogenet 2000;116:47)



Fibroblastic / myofibroblastic tumors

Giant cell fibroblastoma


Reviewer: Komal Arora, M.D. (see Reviewers page)
Revised: 21 July 2012, last major update July 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.

General
=========================================================================

● Rare childhood fibroblastic tumor of intermediate malignancy with floret-like giant cells and ectatic pseudovascular spaces lined by stromal cells and giant cells
● Part of WHO classification for skin tumors, not soft tissue tumors
● Appears to evolve into DFSP by genomic gains of COL1A1-PDGFB (Genes Chromosomes Cancer 2008;47:260)
● Considered the juvenile form of DFSP, as both have the same translocation (Am J Surg Pathol 2003;27:27, Arch Pathol Lab Med 1996;120:1052, Ann Diagn Pathol 2007;11:81)

Epidemiology
=========================================================================

● Usually children less than 10 years old, 2/3 male
● Painless nodule of subcutis, usually in trunk, extremities, head and neck
● 50% recur but recurrences are controllable, no metastases

Case reports
=========================================================================

● 3 year old boy with recurrent knee lesion (Pathol Oncol Res 2003;9:249)
● 28 year old woman with vulvar tumor (J Low Genit Tract Dis 2007;11:112)

Gross description
=========================================================================

● Poorly circumscribed, gray to yellow mucoid mass that is difficult to completely excise, usually in subcutis

Micro description
=========================================================================

● Dermis and subcutis contains hyperchromatic spindle or stellate shaped cells in a collagenous or myxoid matrix with scattered hyperchromatic, multinucleated, floret-like giant cells with prominent nucleoli, similar to those in pleomorphic lipomas
● Ectatic pseudovascular spaces are lined by a discontinuous row of floret-like cells and tumor cells
● Honeycomb or parallel pattern of infiltration
● Also hyalinized area, perivascular lymphocytes in onionskin pattern, intralesional hemorrhage
● Often foci of DFSP
● No histiocyte-like cells, no mitotic figures

Micro images
=========================================================================


       
Ectatic pseudovascular spaces are lined by giant cells


Stroma has giant cells and myxoid stroma


Stroma is fibrotic with giant cells but sparse angiectoid spaces in this case


Multinucleated stromal giant cells have vesicular nuclei and prominent nucleoli, but smaller spindle cells have indistinct nucleoli

Trunk tumor #1, #2, #3

Cytology
=========================================================================

● Moderately cellular smears with mononuclear cells, usually single but occasionally in clusters
● Most cells have no/scanty cytoplasm, bland nuclei with small nucleoli
● Nuclear membranes often have notches, creases or folds
● Rare multinucleated giant cells with bland oval nuclei
● No necrosis, no mitotic figures (Diagn Cytopathol 2002;26:398, Arch Pathol Lab Med 2001;125:1091)

Cytology images
=========================================================================



Various images

Positive stains
=========================================================================

● Vimentin, CD34, CD99 (40%, J Cutan Pathol 2008;35:647)
● Variable actin

Negative stains
=========================================================================

● S100, CD31, Factor VIII, keratin, desmin, HMB45

Molecular
=========================================================================

● t(17,22)(q22;q13) - creates fusion of collagen type 1 alpha 1 gene and platelet derived growth factor B chain gene
● Also supernumerary ring chromosomes derived from t(17;22)

Electron microscopy description
=========================================================================

● Myofibroblasts or fibroblasts

Differential diagnosis
=========================================================================

● Angiosarcoma: older adults in head and neck, vascular tumor, cells have enlarged atypical nuclei, mitotic figures present
● Hemangioma: vascular tumor, no giant cells, CD31+
● Neurofibroma with ancient change: no ectatic vascular spaces, S100+
● Pleomorphic liposarcoma: pleomorphic cells are similar, but remaining lesion has lipoblasts and lacks collagenous matrix

Additional references
=========================================================================

Stanford University



Fibroblastic / myofibroblastic tumors

Hemangiopericytoma


Reviewers: Komal Arora, M.D., Vijay Shankar, M.D. (see Reviewers page)
Revised: 21 February 2013, last major update November 2012
Copyright: (c) 2003-2013, PathologyOutlines.com, Inc.

See variants below: infantile / congenital lipomatous phosphaturic mesenchymal tumor

General
=========================================================================

● Rare, controversial entity
● In soft tissue, most lesions are actually solitary fibrous tumor, monophasic synovial sarcoma or myofibromatosis (Am J Surg Pathol 2010;34:777)
● Diagnosis of exclusion (Histopathology 2006;48:63)
● Historically defined as lesions with thin walled, branching vascular pattern, although this pattern is common in many lesions
● Probably not a lesion of pericytes (cells arranged around capillaries and venules), except at sinonasal location
● See also discussions in these chapters: Bone, Breast, CNS, Heart, Nasal cavity, Thyroid gland

Clinical features
=========================================================================

● Slowly enlarging painless mass of middle aged adults, more common in women
● Most common in deep soft tissue, particularly pelvic retroperitoneum, also limb or limb girdles and head and neck
● Occasionally associated with hypoglycemia (J Clin Endocrinol Metab 1996;81:919)
● 20-50% metastasize to lungs, liver, bone
● 5 year survival was 86% in 2002 (Cancer 2002;95:1746)
● 70% have benign behavior
● Poor prognostic factors may be 4+ mitotic figures/10 HPF, necrosis, nuclear pleomorphism with size > 5 cm

Case reports
=========================================================================

● 4 year old boy with painless jaw mass (J Dent Child (Chic) 2010;77:180)
● 34 year old man with tongue lesion (Braz J Otorhinolaryngol 2012;78:136)
● 37 year old woman with rectal mass (J Med Case Rep 2011;5:352)
● 54 year old woman (Acta Otorhinolaryngol Ital 2011;31:194)
● 61 year old man with omental tumor with metastases (World J Surg Oncol 2007;5:63)
● 70 year old man with spontaneous rupture of cystic splenic tumor (Int J Emerg Med 2011;4:13)

Clinical images
=========================================================================

Jaw mass
Tongue lesion

Gross description
=========================================================================

● Well circumscribed, gray/white to red/brown cut surface, fleshy or spongy with hemorrhage, cystic degeneration, variable necrosis, up to 15 cm

Gross images
=========================================================================

Patient with 3 tumors:

(a) Greater omentum tumor (under forceps)
(b) Small jejunal tumor
(c) Retroperitoneal tumor with portions of diaphragm and liver
Encapsulated omental tumor

Micro description
=========================================================================

● Uniformly cellular (similar to cellular areas of solitary fibrous tumor) with numerous, variably ectatic or compressed, thin walled branching vessels with gaping sinusoidal spaces (staghorn configuration)
● Tumor cells are spindled to round with small amounts of pale or eosinophilic cytoplasm, indistinct margins, bland vesicular nuclei
● May have extensive fibrosis, hyalinization, myxoid change
● Variable mitotic activity
● No atypia

Micro images
=========================================================================

Staghorn vessels and spindle cells
Various images (many from CNS)
Staghorn vessels are prominent
Reticulin stain
Jaw mass
Various images
Rectal mass
Reticulin
Gomori methinamine silver

Cytology
=========================================================================

● Cellular; single and tightly packed clusters of oval to spindle cells aggregated around branched capillaries
● Often basement membrane material present
● Nuclei are uniform, oval, with finely granular chromatin and indistinct nucleoli
● No mitotic figures, no necrosis (Cancer 1999;87:190)

Virtual slides
=========================================================================



Hemangiopericytoma

Positive stains
=========================================================================

● CD99, vimentin, variable CD34 (Hum Pathol 1998;29:636)
● Reticulin surrounds individual cells
● If pericytic differentiation, with silver stain, spindle cells are outside the endothelial basement membrane

Negative stains
=========================================================================

● Factor VIII, CD31, trichrome, usually actin and desmin (except in sinonasal hemangiopericytoma)

Electron microscopy description
=========================================================================

● Has fibroblastic or undifferentiated spindle cell features
● No true pericytic differentiation (pericytic features are cytoplasmic filaments and processes, pinocytotic vesicles, basal lamina, poorly formed intercellular junctions)

Molecular description
=========================================================================

● 12q13-15 alterations in some cases

Differential diagnosis
=========================================================================

● Deep fibrous histiocytoma: storiform pattern, fibrohistiocytic lesion
● Endometrial stromal sarcoma: CD10+, ER+ (Mod Pathol 2005;18:40)
Infantile fibrosarcoma
Mesenchymal chondrosarcoma: islands of mature cartilage; malignant chondrocytes present
MPNST
● Myopericytoma: predominant growth pattern is concentric perivascular arrangement of plump spindle cells (J Clin Pathol 2006;59:67)
Solitary fibrous tumor: more prominent collagen, less prominent vessels
Synovial sarcoma-monophasic:: similar vascular pattern, characteristic translocation
● Thymoma: has epithelial foci

Additional references
=========================================================================

eMedicine, Orphanet, J Pediatr Hematol Oncol 2011;33:356 (childhood tumors)


Infantile / congenital hemangiopericytoma
General
=========================================================================


Micro description
=========================================================================

● Immature cytology, frequent mitotic figures, necrosis, possibly neoplastic endothelial cells

Micro images
=========================================================================

Various images


Lipomatous hemangiopericytoma

General
=========================================================================

● Variant with mature adipose tissue, myxoid and sclerotic areas
● Also called adipocytic variant of solitary fibrous tumor (Hum Pathol 2000;31:1108)
● First described in 1995 (Am J Surg Pathol 1995;19:748)
● May have malignant histologic features (Am J Surg Pathol 2011;35:1177)

Epidemiology
=========================================================================

● Uncommon
● 2/3 males, usually thigh, lower extremity and retroperitoneum
● Only rarely recurs, does not metastasize

Case reports
=========================================================================

● 26 year old man with paratesticular mass (Can Urol Assoc J 2012;6:E131)
● 36 year old woman with tumor of skull base and parapharyngeal space (Otol Neurotol 2006;27:560)
● 39 year old man with mediastinal tumor (J Postgrad Med 2006;52:71)
● 41 year old woman with thigh tumor (Arch Pathol Lab Med 1999;123:941)
● 56 year old man with retroperitoneal mass (Case of the Week # 16)
● 56 year old woman with epigastric pain (World J Gastroenterol 2011;17:4835)

Gross description
=========================================================================

● Solid, tan-yellow

Gross images
=========================================================================



Thigh tumor

Micro description
=========================================================================

● Well circumscribed, patternless cellular areas, prominent hemangiopericytoma-like vessels, mature adipose tissue, variable collagen

Micro images
=========================================================================

Thigh tumor
Mediastinal tumor
Paratesticular
Stomach

Case of the Week #16:
Retroperitoneal mass

Cytology
=========================================================================

● May resemble myxoid liposarcoma (Diagn Cytopathol 2003;29:287)

Positive stains
=========================================================================

● Vimentin, CD99, CD34 (75%), bcl2 (60%)

Negative stains
=========================================================================

● CD31, desmin, keratin, actins, S100, GFAP MDM2 and CDK4

Electron microscopy description
=========================================================================

● Features of pericytes, no lipoblasts

Differential diagnosis
=========================================================================

● Various lipomas
● Liposarcoma (Am J Surg Pathol 1999;23:1201)



Fibroblastic / myofibroblastic tumors

Inclusion body fibromatosis


Reviewer: Komal Arora, M.D. (see Reviewers page)
Revised: 21 July 2012, last major update July 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.

General
=========================================================================

● Dermal fibroblastic and myofibroblastic lesion with cytoplasmic eosinophilic inclusions, usually in digits of infants
● Also called infantile digital fibromatosis, infantile digital fibroma (J Hand Surg Am 1995;20:1014)
● Distinct lesion from classic fibromatosis (Am J Surg Pathol 2009;33:1)

Clinical description
=========================================================================

● Rare; lesions usually present at birth or in first 2 years
● Similar lesions in adults
● Often are multiple

Sites
=========================================================================

● Usually exterior surface of distal phalanges of fingers and toes, but not thumb or great toe, also oral cavity and breast
● 50% recur, do not metastasize
● Similar inclusions reported in breast fibroadenoma (Arch Pathol Lab Med 2007;131:1126), breast phyllodes tumor (Am J Surg Pathol 1994;18:506, Breast J 2008;14:198), cervical polyp (Pathology 1998;30:215), GI leiomyomas (Cesk Patol 2006;42:139)

Case reports
=========================================================================

● 6 month old girl (Indian J Pathol Microbiol 2010;53:827)
● 1 year old boy with spontaneous regression (J Dermatol 1998;25:523)
● 2 year old with post-surgical involvement of all 4 extremities (Ann Plast Surg 2008;61:472)

Treatment
=========================================================================

● Conservative excision (preserve function because recurrences are not destructive and tumors do not metastasize) or watchful waiting (Am J Surg Pathol 2009;33:1, Pediatr Dermatol 2008;25:72)

Clinical images
=========================================================================


   
Various images

Gross description
=========================================================================

● Nodules with stretched overlying skin, lesions are ill defined, white-tan, usually 2 cm or less
● No hemorrhage or necrosis

Micro description
=========================================================================

● Nonencapsulated, dermal proliferation of hypocellular sheets or fascicles of fibroblasts and myofibroblasts with variable collagen
● Some spindle cells have peculiar eosinophilic (hyaline) cytoplasmic inclusions the size of a lymphocyte nucleus
● Usually mitotic figures
● May infiltrate into adjacent tissue
● No atypia

Micro images
=========================================================================



Proliferation extends from epidermis to deep dermis or subcutis


Fibroblastic cells swirl around and engulf an eccrine duct


Cells are bland and monomorphic


Inclusions resemble red blood cells


Various images

Cytology
=========================================================================

Acta Cytol 2011;55:481

Positive stains
=========================================================================

Inclusions - trichrome (stain red), PTAH, variable staining for actins
Spindle cells - vimentin, muscle actins (tram track pattern), calponin, desmin, CD99; often CD117

Negative stains
=========================================================================

Inclusions - PAS
Spindle cells - keratin, ER, PR, beta-catenin

Electron microscopic description
=========================================================================

● Spindle cells are myofibroblasts with rough endoplasmic reticulum and free lying inclusions composed of compact masses of actin granules and filaments without a limiting membrane (Am J Pathol 1979;94:19)

Differential diagnosis
=========================================================================

● Infantile fibrosarcoma: not digits, usually > 2 cm, more cellular, chromatin is denser and more irregular, more mitotic figures, no inclusions
● Infantile desmoid fibromatosis: rare on hand, usually > 2 cm, more cellular, no inclusions

Additional references
=========================================================================

Stanford University



Fibroblastic / myofibroblastic

Inflammatory myofibroblastic tumor of soft tissue


Reviewer: Komal Arora, M.D. (see Reviewers page)
Revised: 18 July 2012, last major update July 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.

General
=========================================================================

● Tumor of myofibroblasts with plasma cells, lymphocytes and eosinophils
● Also called inflammatory fibrosarcoma, inflammatory pseudotumor, plasma cell granuloma
● See also discussions in these chapters: Bladder, Bone, Breast nonmalignant, CNS tumor, Colon tumor, Eye (orbit), Heart tumor, Kidney tumor, Liver tumor, Lung tumor, Lymph node-not lymphoma, Mediastinum, Pancreas, Salivary glands, Small bowel, Spleen, Thyroid gland
● Retroperitoneum (omentum) and mesentery in children and young adults (mean age 10 years)
● Also lung, GI, GU, other sites

Poor prognostic factors:
● Abdominal or pelvic sites, ALK negative (Am J Surg Pathol 2007;31:509)

Clinical description
=========================================================================

● 1/3 have associated fever, growth failure, malaise, weight loss, anemia, thrombocytosis, polyclonal hyperglobulinemia and elevated sedimentation rate
● Symptoms disappear after excision of mass (J Korean Med Sci 2002;17:699)

Case reports
=========================================================================

● 6 year old boy with abdominal wall tumor (Surg Today 2007;37:352)
● 7 year old girl whose abdominopelvic tumor has t(1;2)(q21;p23) (Arch Pathol Lab Med 2006;130:1042)
● 18 year old man with omental tumor and bone marrow involvement (Arch Pathol Lab Med 2003 Jul;127:865)
● 46 year old woman with retroperitoneal tumor (World J Surg Oncol 2005;3:66)
● 63 year old man with mesenteric tumor (World J Gastroenterol 2007;13:3645)

Treatment
=========================================================================

● Excision (J Pediatr Surg 2005;40:1581)
● 25-35% recur, rare metastases (or may be evidence of multifocality)

Gross description
=========================================================================

● Circumscribed, not encapsulated
● White tan mass with whorled fleshy or myxoid cut surface
● May have focal hemorrhage, necrosis or calcification, mean 6 cm

Gross images
=========================================================================


19 cm mesenteric tumor (fig 2-4)

Micro description
=========================================================================

● Myofibroblastic and fibroblastic spindle cells with inflammatory infiltrate of lymphocytes, plasma cells, eosinophils, histiocytes
● Background of abundant blood vessels
● Mixture of three patterns:
  (1) resembling nodular fasciitis with elongated myofibroblasts containing abundant eosinophilic cytoplasm and vesicular nuclei, loose myxoid stroma with neutrophils, lymphocytes and eosinophils, but few plasma cells;
  (2) cellular with spindled myofibroblasts and fibroblasts in more compact stroma, arranged as islands surrounded by fibromyxoid stroma with prominent plasma cells and mitotic figures;
  (3) densely hyalinized stroma with few spindle cells, few plasma cells or lymphocytes
● May have ganglion-cell like myofibroblasts
● All 3 patterns have no nuclear pleomorphism, no atypical mitotic figures
Malignant behavior - associated with highly atypical polygonal cells with oval nuclei, prominent nucleoli, Reed-Sternberg like cells, atypical mitotic figures

Micro images
=========================================================================


   
Typical appearance of spindled myofibroblastic cells and inflammatory infiltrate


Inflammation obscures the underlying myofibroblastic proliferation


Spindle cells are evident at high power


Tumor with more fibrous stroma

           
Myofibroblasts and inflammatory cells

           
Various images

Retroperitoneal tumor #1, #2, #3, #4

       
H&E, ALK1 and p80

Virtual slides
=========================================================================



Inflammatory myofibroblastic tumor

Electron microscopy description
=========================================================================

● Myofibroblastic cells and activated fibroblasts

Electron microscopy images
=========================================================================



Figure b: filamentous bundles, attachment densities, pinocytotic vesicles and basal lamina

Positive stains
=========================================================================

● Vimentin (diffuse, strong), usually alpha smooth muscle actin, muscle specific actin and calponin (Hum Pathol 2008;39:846)
● ALK1 / p80 in 40%, but not specific (Mod Pathol 2002;15:931)
● Keratin and desmin in 1/3

Negative stains
=========================================================================

● S100, CD117, HHV8 (Mod Pathol 2007;20:995)
● CD34, h-caldesmon

Molecular
=========================================================================

● Clonal abnormalities of 2p23 (Cancer Res 1999;59:2776) including t(2;5)(p23;q35) involving ALK and NPM
● Also t(2;17)(p23;q23) involving ALK and CLTC (Am J Pathol 2001;159:411) and t(2;19)(p23;p13.1) involving ALK and TPM4 (Am J Pathol 2000;157:377)
● Associated with ALK deregulation and younger patients
● See Atlas of Genetics

Molecular images
=========================================================================



t(2;5) karyotype


ALK translocation is indicated by separation of green and orange probes of ALK gene in inflammatory myofibroblastic tumor (a), but not leiomyosarcoma (b)


ALK staining, FISH and karyotype


FISH for ALK

Differential diagnosis
=========================================================================

● Calcifying fibrous pseudotumor: calcification, no myofibroblastic proliferation, actin negative (Mod Pathol 2001;14:784)
● Nodular fasciitis: smaller size, older patients, less inflammation
● Low grade myofibroblastic sarcoma: more uniform appearance with higher cellularity, more prominent hyperchromasia, more infiltrative, ALK (Hum Pathol 2008;39:846)
● IgG4 related sclerosing lesion: IgG4+ plasma cells and the ratio of IgG4+/IgG+ plasma cells is lower in IMT
● The presence of obstructive phlebitis
● Absence of ALK (Mod Pathol 2011;24:606, Am J Surg Pathol 2009;33:1330)



Fibroblastic / myofibroblastic tumors
Intranodal palisaded myofibroblastoma

Reviewer: Lauren N. Stuart M.D., M.B.A. (see Reviewers page)
Editor: Jerad M. Gardner, M.D.
Revised: 15 April 2013, last major update April 2013
Copyright: (c) 2002-2013, PathologyOutlines.com, Inc.

Definition
=========================================================================
Terminology
=========================================================================
Epidemiology
=========================================================================
Sites
=========================================================================
Pathophysiology
=========================================================================
Clinical features
=========================================================================
Prognostic factors
=========================================================================
Case reports
=========================================================================
Treatment
=========================================================================
Gross description
=========================================================================
Gross images
=========================================================================
Lymph node with areas of hemorrhage

Micro description
=========================================================================

5 key features:
  1. Spindle cell proliferation surrounded by hemorrhage and collagenous pseudocapsule; growing nodule compresses remaining nodal tissue
  2. Bland spindle cells with areas of nuclear palisading
  3. Intraparenchymal hemorrhage and red blood cell extravasation
  4. So-called amianthoid fibers
  5. Extra- and intracellular fuchsinophilic bodies (best seen with SMA stain, Arch Pathol Lab Med 2007;131:306)
Micro images
=========================================================================
Figure 1
Various images
Various images
Fig 1: Amianthoid fibers composed of a central vessel surrounded by a core of collagen with peripheral spokes, strongly stained by Van Gieson (elastin)

Various images
Various images

Cytology description
=========================================================================
Positive stains
=========================================================================
Negative stains
=========================================================================
Electron microscopy description
=========================================================================
Differential diagnosis
=========================================================================


Fibroblastic / myofibroblastic tumors
Ischemic fasciitis

Reviewer: Ali Chaudhri, M.D. (see Reviewers page)
Editor: Jerad M. Gardner, M.D.
Revised: 20 June 2013, last major update June 2013
Copyright: (c) 2002-2013, PathologyOutlines.com, Inc.

Definition
=========================================================================
Epidemiology
=========================================================================
Sites
=========================================================================
Etiology
=========================================================================
Case reports
=========================================================================
Treatment
=========================================================================
Gross description
=========================================================================
Micro description
=========================================================================
Micro images
=========================================================================

AFIP images:
Figure 1
Figure 2
Figure 3
Fig 1: cellular, fibrin-rich proliferation centered on subcutaneous fibrous septum and extending into adjacent fat
Fig 2: hyalinized focus with large ganglion-like cells, suggestive of proliferative fasciitis
Fig 3: fibrin is adjacent to foci of ganglion-like cells in collagenous stroma


Other:
Fibrinoid necrosis with few viable cells
Spindle cells with large nuclei with prominent nucleoli
Post-mastectomy axillary mass-various images

Case of the week #64 - Hip mass in 55 year old bedridden man:
Cytology description
=========================================================================
Positive stains
=========================================================================
Negative stains
=========================================================================
Differential diagnosis
=========================================================================
Additional references
=========================================================================


Fibroblastic / myofibroblastic tumors
Juvenile hyaline fibromatosis

Reviewer: Lauren N. Stuart, M.D., M.B.A. (see Reviewers page)
Editor: Jerad M. Gardner, M.D.
Revised: 15 April 2013, last major update April 2013
Copyright: (c) 2002-2013, PathologyOutlines.com, Inc.

Definition
=========================================================================
Terminology
=========================================================================
Epidemiology
=========================================================================
Sites
=========================================================================
Etiology
=========================================================================
Clinical features
=========================================================================
Laboratory
=========================================================================
Radiology
=========================================================================
Case reports
=========================================================================
Treatment
=========================================================================
Clinical images
=========================================================================
Multiple subcutaneous nodules
Nodules on pinna of ear
Large ulcerated nodules on back
Gingival hyperplasia
Multiple skin papules
Recurrent lesions

Gross description
=========================================================================
Gross images
=========================================================================
Nodules with gelatinous surface

Micro description
=========================================================================
Micro images
=========================================================================
Sparse, uniform spindle cells
PAS+ matrix

Amorphous hyaline matrix in dermis with fibroblasts

Dermal oval/polygonal cells with retraction artifact

Cytology description
=========================================================================
Cytology images
=========================================================================
Scant spindle cells

Positive stains
=========================================================================
Negative stains
=========================================================================
Electron microscopy description
=========================================================================
Differential diagnosis
=========================================================================
Additional references
=========================================================================


Fibroblastic / myofibroblastic tumors
Lipofibromatosis

Reviewer: Ali Chaudhri, M.D. (see Reviewers page)
Editor: Jerad M. Gardner, M.D.
Revised: 20 June 2013, last major update June 2013
Copyright: (c) 2002-2013, PathologyOutlines.com, Inc.

Definition
=========================================================================
Epidemiology
=========================================================================
Clinical features
=========================================================================
Case reports
=========================================================================
Gross description
=========================================================================
Micro description
=========================================================================
Positive stains
=========================================================================
Negative stains
=========================================================================
Molecular / cytogenetics description
=========================================================================
Differential diagnosis
=========================================================================


Fibroblastic / myofibroblastic tumors
Low-grade fibromyxoid sarcoma

Reviewer: Raul Gonzalez, M.D. (see Reviewers page)
Editor: Jerad M. Gardner, M.D.
Revised: 25 April 2013, last major update April 2013
Copyright: (c) 2002-2013, PathologyOutlines.com, Inc.

Definition
=========================================================================
Epidemiology
=========================================================================
Clinical features
=========================================================================
Prognostic factors
=========================================================================
Radiology
=========================================================================
Case reports
=========================================================================
Treatment
=========================================================================
Gross description
=========================================================================
Gross images
=========================================================================
Tumor of falciform ligament
Well- circumscribed tumor of leg
Well- circumscribed tumor with giant rosettes
Low-grade fibromyxoid sarcoma
Figure 5
Micro description
=========================================================================
Micro images
=========================================================================

AFIP:
Figure 1
Figure 2
Figure 3
Fig 1: characteristic features include fibrous and myxoid areas, a swirling whorled growth pattern, low to moderate cellularity and bland cells with minimal nuclear pleomorphism
Fig 2: the swirling growth pattern is storiform
Fig 3: there is a relatively linear cell arrangement in this area, but other areas have the characteristic swirling and whorled pattern


Other:
Figure 6
Figure 7
Figure 8
Myxoid area showing arcades of blood vessels
Storiform pattern
Bland spindle cells in fibromyxoid stroma
Rosettes in spindled stroma
Covered by pelvic urothelium
Alternating fibrous and myxoid areas
Cells forming rosettes are PGP 9.5+, Factor XIII negative
Staining of vessels but not tumor by CD34, smooth muscle actin
Vimentin+

Contributed by Mark Rodacker:
Various images
Cytology description
=========================================================================
Cytology images
=========================================================================
Figure 1
Figure 2
Figure 3
Figure 4
Virtual slides
=========================================================================
Low grade fibromyxoid sarcoma

LGFMS from Jerad M. Gardner, MD,
Virtual Soft Tissue Pathology Study Set
Positive stains
=========================================================================
Negative stains
=========================================================================
Electron microscopy description
=========================================================================
Electron microscopy images
=========================================================================
Rosette-forming cells have dense core granules
Figure 9
Molecular / cytogenetics description
=========================================================================
Molecular / cytogenetics images
=========================================================================
Complex karyotype includes t(7;16)
Differential diagnosis
=========================================================================
Additional references
=========================================================================


Fibroblastic / myofibroblastic tumors
Low-grade myofibroblastic sarcoma

Reviewer: Raul Gonzalez, M.D. (see Reviewers page)
Editor: Jerad M. Gardner, M.D.
Revised: 25 April 2013, last major update April 2013
Copyright: (c) 2002-2013, PathologyOutlines.com, Inc.

Definition
=========================================================================
Epidemiology
=========================================================================
Treatment
=========================================================================
Gross description
=========================================================================
Micro description
=========================================================================
Micro images
=========================================================================
Breast: H&E shows fascicular growth (fig 1A), alpha smooth muscle actin+ (fig 1B) and vimentin+ (insert), fibronectin+ matrix (fig 1C), type IV collagen negative (fig 1D)
Femur: hypocellular area with a proliferation of spindle cells with abundant intercellular collagen (A); hypercellular area with a proliferation of spindle cells with hyperchromatic enlarged nuclei and abundant intercellular collagen
Femur: additional images, including staining for smooth muscle actin
Positive stains
=========================================================================
Negative stains
=========================================================================
Electron microscopy description
=========================================================================
Molecular / cytogenetics description
=========================================================================
Differential diagnosis
=========================================================================
Additional references
=========================================================================


Fibroblastic / myofibroblastic tumors
Mammary-type myofibroblastoma

Reviewer: Deepti Reddi, M.D. (see Reviewers page)
Editor: Jerad M. Gardner, M.D.
Revised: 26 April 2013, last major update April 2013
Copyright: (c) 2002-2013, PathologyOutlines.com, Inc.

Definition
=========================================================================
Epidemiology
=========================================================================
Sites
=========================================================================
Etiology
=========================================================================
Clinical features
=========================================================================
Case reports
=========================================================================
Treatment
=========================================================================
Gross description
=========================================================================
Gross images (breast)
=========================================================================
Well circumscribed lesion with white whorled cut surface
Micro description
=========================================================================
Micro images (breast)
=========================================================================
AFIP: circumscribed border
AFIP: fascicles of spindle cells separated by dense collagen bundles
Scattered mast cells
Fascicles of spindled and oval cells separated by bands of thick collagen
Classic type
Cellular, epithelioid, and deciduoid-like variants
Lipomatous, collagenized/fibrous, myxoid, and epitheliod variants
CD34+
Cytology description (breast)
=========================================================================
Cytology images (breast)
=========================================================================
Loose groups of cells with abundant eosinophilic granular cytoplasm and bland nuclei
Positive stains
=========================================================================
Molecular / cytogenetics description
=========================================================================
Molecular / cytogenetics images
=========================================================================
FISH for cellular angiofibroma-13q
Differential diagnosis
=========================================================================
Additional references
=========================================================================


Fibroblastic / myofibroblastic tumors
Myofibroma / myofibromatosis

Reviewer: Deepti Reddi, M.D. (see Reviewers page)
Editor: Jerad M. Gardner, M.D.
Revised: 26 April 2013, last major update April 2013
Copyright: (c) 2002-2013, PathologyOutlines.com, Inc.

Definition
=========================================================================
Terminology
=========================================================================
Epidemiology
=========================================================================
Sites
=========================================================================
Etiology
=========================================================================
Clinical features
=========================================================================
Radiology
=========================================================================
Prognostic factors
=========================================================================
Case reports
=========================================================================
Treatment
=========================================================================
Gross description
=========================================================================
Micro description
=========================================================================
Micro images
=========================================================================

AFIP:
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Fig 1: Solitary cutaneous lesion features zones of fibrous tissue with bundles of myofibroblasts and prominent thin-walled vessels
Fig 2: High power shows interface with normal collagen
Fig 3: Biphasic with immature cells in hemangiopericytoma pattern and bundles of myofibroblastic cells
Fig 4: Central hemangiopericytic area is rimmed by hyalinized myofibroblastic area
Fig 5: Junction between myofibroblastic cells and immature spindled cells
Fig 6: Myofibroblastic spindle cells and immature cells are arranged in hemangiopericytic pattern

Other:
Infant lesion, arm tumor
Poorly circumscribed nodular tumor
Well circumscribed tumor
Fascicles of spindle cells resemble leiomyoma
Cellular and keloid-like areas #1
Cellular and keloid-like areas #2
Cellular and keloid-like areas #3
Cellular and keloid-like areas #4
Intracranial tumor
Various images
Dermis is infiltrated by fascicles of smooth muscle-like cells

Trichrome stain (fig B) highlights prominent
collagen not seen on H&E (fig A)

48 year old woman with nodules on scalp:
Myofibroblasts around capillaries and sclerosing areas
Tumor infiltrates skeletal muscle
Hemangio-pericytoma-like vascular pattern
Fascicles of myofibroblastic cells with oval nuclei
Smooth muscle actin+
Tumor is CD34-, desmin-; vessels are CD34+ desmin+
Virtual slides
=========================================================================
Myofibroma (from Jerad M. Gardner, MD - Virtual Soft Tissue Pathology Study Set)
Positive stains
=========================================================================
Negative stains
=========================================================================
Electron microscopy description
=========================================================================
Differential diagnosis
=========================================================================


Fibroblastic / myofibroblastic tumors
Myositis ossificans

Reviewer: Daniel Wimmer, D.O. (see Reviewers page)
Editor: Jerad M. Gardner, M.D.
Revised: 8 June 2013, last major update June 2013
Copyright: (c) 2002-2013, PathologyOutlines.com, Inc.

Definition
=========================================================================
Terminology
=========================================================================
Epidemiology
=========================================================================
Sites
=========================================================================
Radiology
=========================================================================
Case reports
=========================================================================
Treatment
=========================================================================
Gross description
=========================================================================
Gross images
=========================================================================
Bone fragment from abdominal wall
Micro description
=========================================================================
Micro images
=========================================================================

Images from AFIP:
Mature bone at periphery, fibrous tissue resembling nodular fasciitis at center, osteoid in between
Fibroblastic and myofibroblastic cells in center of lesion resemble nodular fasciitis, with nuclear uniformity
Osteoid is broader than in osteosarcoma
Figure 1
Figure 2
Osteoid undergoing mineralization
Fig 1: Osteoblasts have large nuclei with prominent nucleoli, but clues to benign nature of lesion are reactive fibrous areas
Fig 2: Osteoid deposition is uniform, and nuclei are enlarged but not pleomorphic


Other images:
2x
10x
40x
Various images of thigh lesion
Cytology images
=========================================================================
Hip mass with FNA showing crystals consistent with calcium
Virtual slides
=========================================================================
Myositis ossificans
Positive stains
=========================================================================
Electron microscopy description
=========================================================================
Molecular / cytogenetics description
=========================================================================
Differential diagnosis
=========================================================================


Fibroblastic / myofibroblastic tumors
Myxofibrosarcoma

Reviewer: Annie S. Morrison, M.D. (see Reviewers page)
Editor: Jerad M. Gardner, M.D.
Revised: 15 April 2013, last major update April 2013
Copyright: (c) 2002-2013, PathologyOutlines.com, Inc.

Definition
=========================================================================
Epidemiology
=========================================================================
Clinical features
=========================================================================
Prognostic factors
=========================================================================
Case reports
=========================================================================
Treatment
=========================================================================
Gross description
=========================================================================
Gross images
=========================================================================
Thigh tumor
Lower extremity tumor
Subcutaneous tumor
Micro description
=========================================================================
Grading: Micro images
=========================================================================

AFIP:
Myxoid areas may have pleomorphic cells and variable cellularity
Moderate cellularity with pleomorphic cells
Typical cellular areas with occasional giant cells
Grade I tumor has the minimal pleomorphism required for diagnosis
Grade II tumor: myxoid areas alternate with solid area that is not as pleomorphic as usual undifferentiated pleomorphic sarcoma

Grade III tumor with markedly
pleomorphic areas (left) and
myxoid areas (right), myxoid
areas may lack pleomorphic cells

Resembling ischemic or proliferative fasciitis:     Not myxofibrosarcoma due to lack of pleomorphism:
Myxoid stroma with low density of ganglion-like cells
Bizarre cells are strongly suggestive of malignancy, not a reactive condition
             
These lesions are called juxta-articular myxoma, cellular intramuscular myxoma or myxoid lesion with recurrent potential, they may recur but do not metastasize (controversial lesions)
Typical histology
Spindle-shaped cells
Metastatic lesion of clavicle
Myxoid nodules and fibrous septa
Spindle-shaped cells
Lipoblast-like cells
Curvilinear capillaries

Cytology description
=========================================================================
Positive stains
=========================================================================
Negative stains
=========================================================================
Electron microscopy description
=========================================================================
Electron microscopy images
=========================================================================
Maxillary sinus tumor
Molecular / cytogenetics description
=========================================================================
Differential diagnosis
=========================================================================


Fibroblastic / myofibroblastic tumors
Myxoinflammatory fibroblastic sarcoma

Reviewer: Annie S. Morrison, M.D. (see Reviewers page)
Editor: Jerad M. Gardner, M.D.
Revised: 15 April 2013, last major update April 2013
Copyright: (c) 2002-2013, PathologyOutlines.com, Inc.

Definition
=========================================================================
Epidemiology
=========================================================================
Case reports
=========================================================================
Treatment
=========================================================================
Gross description
=========================================================================
Micro description
=========================================================================
Micro images
=========================================================================
Fibrous region with inflammatory cells
Myxoid region with inflammatory cells
Acute inflammatory cells

AFIP: myxoid nodule has
characteristic ganglion-type
cells with prominent nucleoli
Nodules of cells infiltrating ulnar nerve
Sheetlike proliferation of spindle cells
Spindle cells with prominent nucleoli
Various images
Figures 2, 3, 4
Cytology description
=========================================================================
Cytology images
=========================================================================
Figure 1

Positive stains
=========================================================================
Negative stains
=========================================================================
Electron microscopy description
=========================================================================
Molecular / cytogenetics description
=========================================================================
Differential diagnosis
=========================================================================


Fibroblastic / myofibroblastic tumors
Nodular fasciitis

Reviewer: Daniel Wimmer, D.O. (see Reviewers page)
Editor: Jerad M. Gardner, M.D.
Revised: 9 June 2013, last major update June 2013
Copyright: (c) 2002-2013, PathologyOutlines.com, Inc.

See subtypes below: cranial fasciitis, intravascular fasciitis, proliferative funiculitis

General
=========================================================================
Epidemiology
=========================================================================
Case reports
=========================================================================
Treatment
=========================================================================
Gross description
=========================================================================
Gross images
=========================================================================
Scapular lesion
Intraoperative mass within deltoid muscle
Micro description
=========================================================================
Micro images
=========================================================================

Images from AFIP:
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Fig 1: Subcutaneous tumor is partially circumscribed nodule infiltrating focally along fascial planes
Fig 2: Focal infiltration into fat, with evenly distributed granulation tissue-like vessels throughout the lesion
Fig 3: Gently curving C and S shaped fascicles of myofibroblastic cells exhibit a characteristic "torn Kleenex" pattern
Fig 4: Focal storiform pattern is suggestive of fibrous histiocytoma
Fig 5: Plump spindled myofibroblastic cells and extravasated red blood cells

Figure 6
Figure 7
Figure 8
Cystic degeneration
Fig 6: Mitotic figures but no abnormal forms
Fig 7: Focally more collagenous stroma with skeletal muscle involvement
Fig 8: Osteoclastic giant cells are present in less collagenous areas, suggesting a variant of MFH

Figure 9
Figure 10
Figure 11
Fig 9: Hyalinized variant resembles keloid or fibromatosis
Fig 10: Vague zonation pattern with bone formation in lower right
Fig 11: Island of new bone surrounded by myofibroblastic cells


Other images:
Leg lesion
Leg lesion-5 resembles fibroblast culture
Figure 1
Figure 2
Figure 3
Fig 1: Spindled fibroblasts and extravasated red blood cells in myxoid background, with giant cells (blue arrows) and mitotic figures (red arrows)
Fig 2: Myofibroblasts and staghorn blood vessels
Fig 3: "Tram track" pattern of actin expression in myofibroblasts

Case of the Week #65 / tumor of wrist:
Cytology description
=========================================================================
Positive stains
=========================================================================
Negative stains
=========================================================================
Electron microscopy description
=========================================================================
Molecular / cytogenetics description
=========================================================================
Differential diagnosis
=========================================================================


Cranial fasciitis

Reviewer: Ricardo M. Mendoza, M.D. (see Reviewers page)
Editor: Jerad M. Gardner, M.D.

Definition
=========================================================================
Epidemiology
=========================================================================
Sites
=========================================================================
Pathophysiology
=========================================================================
Etiology
=========================================================================
Clinical features
=========================================================================
Radiology
=========================================================================
Case reports
=========================================================================
Treatment
=========================================================================
Gross description
=========================================================================
Micro description
=========================================================================
Micro images
=========================================================================
Resembles usual nodular fasciitis
Spindle cells lack cytologic atypia
Increased mitotic activity
Positive stains
=========================================================================
Negative stains
=========================================================================
Differential diagnosis
=========================================================================


Intravascular fasciitis

Reviewer: Lauren N. Stuart, M.D., M.B.A. (see Reviewers page)
Editor: Jerad M. Gardner, M.D.

Definition
=========================================================================
Epidemiology
=========================================================================
Sites
=========================================================================
Etiology
=========================================================================
Case reports
=========================================================================
Treatment
=========================================================================
Gross description
=========================================================================
Micro description
=========================================================================
Micro images
=========================================================================

AFIP:
Large focus of nodular fasciitis protrudes into vascular space
Cellular proliferation has edematous background characteristic of nodular fasciitis

Other:
Intravascular proliferation of uniform spindle cells
Low power, H&E
High power, H&E
Initial biopsy
Re-excision
Positive stains
=========================================================================
Negative stains
=========================================================================
Differential diagnosis
=========================================================================


Proliferative funiculitis

Reviewer: Lauren N. Stuart, M.D., M.B.A. (see Reviewers page)
Editor: Jerad M. Gardner, M.D.

Definition
=========================================================================
Terminology
=========================================================================
Epidemiology
=========================================================================
Sites
=========================================================================
Etiology
=========================================================================
Clinical features
=========================================================================
Laboratory
=========================================================================
Radiology
=========================================================================
Prognostic factors
=========================================================================
Treatment
=========================================================================
Gross description
=========================================================================
Gross / clinical images
=========================================================================
Inguinal tumor
Tumor in undescended testis
Micro description
=========================================================================
Micro images
=========================================================================
Spindle cell proliferation
Positive stains
=========================================================================
Negative stains
=========================================================================
Differential diagnosis
=========================================================================


Fibroblastic / myofibroblastic tumors
Nuchal fibrocartilaginous pseudotumor

Reviewer: Ricardo M. Mendoza, M.D. (see Reviewers page)
Editor: Jerad M. Gardner, M.D.
Revised: 15 April 2013, last major update April 2013
Copyright: (c) 2002-2013, PathologyOutlines.com, Inc.

Definition
=========================================================================
Terminology
=========================================================================
Epidemiology
=========================================================================
Sites
=========================================================================
Pathophysiology
=========================================================================
Etiology
=========================================================================
Clinical features
=========================================================================
Radiology
=========================================================================
Case reports
=========================================================================
Treatment
=========================================================================
Gross description
=========================================================================
Micro description
=========================================================================
Micro images
=========================================================================
Fibrocartilage surrounded by disorganized collagen bundles

Positive stains
=========================================================================
Negative stains
=========================================================================
Electron microscopy description
=========================================================================
Differential diagnosis
=========================================================================


Fibroblastic / myofibroblastic tumors
Nuchal-type and Gardner-associated fibroma

Reviewer: Christine E. Jabcuga, M.D. (see Reviewers page)
Editor: Jerad M. Gardner, M.D.
Revised: 21 June 2013, last major update June 2013
Copyright: (c) 2002-2013, PathologyOutlines.com, Inc.

Definition
=========================================================================
Epidemiology
=========================================================================
Case reports
=========================================================================
Treatment
=========================================================================
Gross description
=========================================================================
Micro description
=========================================================================
Micro images
=========================================================================

AFIP images:             Other images:
Strands of acellular collagen mixed with fat
Lesion is very hypocellular, differentiating it from fibromatosis
Figures 2-7
Positive stains
=========================================================================
Negative stains
=========================================================================
Differential diagnosis
=========================================================================


Fibroblastic / myofibroblastic tumors
Ossifying fibromyxoid tumor

Reviewer: Ashley Gullett, M.D. (see Reviewers page)
Editor: Jerad M. Gardner, M.D.
Revised: 20 June 2013, last major update June 2013
Copyright: (c) 2002-2013, PathologyOutlines.com, Inc.

Definition
=========================================================================
Clinical features
=========================================================================
Prognostic factors
=========================================================================
Case reports
=========================================================================
Treatment
=========================================================================
Gross description
=========================================================================
Micro description
=========================================================================
Micro images
=========================================================================
Various images
Cytology description
=========================================================================
Positive stains
=========================================================================
Negative stains
=========================================================================
Electron microscopy description
=========================================================================
Molecular / cytogenetics description
=========================================================================


Fibroblastic / myofibroblastic tumors
Pleomorphic fibroma of skin

Reviewer: Christine E. Jabcuga, M.D. (see Reviewers page)
Editor: Jerad M. Gardner, M.D.
Revised: 21 June 2013, last major update June 2013
Copyright: (c) 2002-2013, PathologyOutlines.com, Inc.

Definition
=========================================================================
Clinical features
=========================================================================
Case reports
=========================================================================
Micro description
=========================================================================
Micro images
=========================================================================

AFIP images:
Large pleomorphic cells separated by collagen

Atypical cells have smudged chromatin,
mitoses are absent/rare, compare to sarcomas
with abnormal (but not degenerative) nuclei
and frequent mitotic figures, some atypical

Other images:
Anal skin
Various images
Stromal cells have atypical nuclei
Various images
Cytology description
=========================================================================
Cytology images
=========================================================================
Pleomorphic cells with very large nuclei
Pleomorphic cells scattered between collagen bundles
Vimentin+
Positive stains
=========================================================================
Negative stains
=========================================================================
Differential diagnosis
=========================================================================


Fibroblastic / myofibroblastic tumors
Proliferative fasciitis

Reviewer: Meggen Walsh, M.D. (see Reviewers page)
Editor: Jerad M. Gardner, M.D.
Revised: 13 June 2013, last major update June 2013
Copyright: (c) 2002-2013, PathologyOutlines.com, Inc.

See childhood variant below

Definition
=========================================================================
Clinical features
=========================================================================
Case reports
=========================================================================
Treatment
=========================================================================
Gross description
=========================================================================
Micro description
=========================================================================
Micro images
=========================================================================

Images from AFIP:
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Fig 1: Prominent hemorrhage and vague centering of cellular proliferation on interlobar septa of subcutaneous fat
Fig 2: Mixture of ganglion-like cells, myofibroblasts and inflammatory cells
Fig 3: Ganglion-like cells have abundant amphophilic cytoplasm and prominent nucleoli
Fig 4: Ganglion-like cells mixed with inflammatory cells within myxohyaline matrix
Fig 5: Condensed around thin walled vascular channel


Other images:
Myofibroblasts and fibroblasts
Ganglion-like cells

Stains:
van Gieson stain
Alcian blue-PAS
Cytology description
=========================================================================
Positive stains
=========================================================================
Negative stains
=========================================================================
Differential diagnosis
=========================================================================


Childhood variant
Gross description
=========================================================================
Micro description
=========================================================================
Micro images
=========================================================================
Ganglion-like cells
Ganglion-like cells with infiltrate
Lobulated growth pattern
Differential diagnosis
=========================================================================


Fibroblastic / myofibroblastic tumors
Proliferative myositis

Reviewer: Meggen Walsh, M.D. (see Reviewers page)
Editor: Jerad M. Gardner, M.D.
Revised: 9 June 2013, last major update June 2013
Copyright: (c) 2002-2013, PathologyOutlines.com, Inc.

Definition
=========================================================================
Epidemiology
=========================================================================
Sites
=========================================================================
Pathophysiology
=========================================================================
Etiology
=========================================================================
Treatment
=========================================================================
Gross description
=========================================================================
Micro description
=========================================================================
Micro images
=========================================================================

Images from AFIP:
Characteristic checkerboard pattern is produced by reactive proliferation expanding spaces between muscle bundles and individual muscle fibers
With metaplastic bone, resembling myositis ossificans
Large ganglion cells with crowding and molding resembling carcinoma
Cells have abundant amphophilic cytoplasm and prominent nucleoli
Other images:
Ganglion cells

Spindle cell sarcoma resembling proliferative fasciitis - AFIP:
Figure 1
Figure 2
Fig 1: Checkerboard pattern produced by infiltration of tumor cells between muscle bundles without myocyte necrosis
Fig 2: Cellular proliferation of atypical spindle cells differs from bland spindle cells of proliferative myositis

Cytology description
=========================================================================
Positive stains
=========================================================================
Negative stains
=========================================================================
Electron microscopy description
=========================================================================
Differential diagnosis
=========================================================================


Fibroblastic / myofibroblastic tumors
Proliferative peribursitis

Reviewer: Cliff Sullivan, M.D. (see Reviewers page)
Editor: Jerad M. Gardner, M.D.
Revised: 9 June 2013, last major update June 2013
Copyright: (c) 2002-2013, PathologyOutlines.com, Inc.

Definition
=========================================================================
Epidemiology
=========================================================================
Clinical features
=========================================================================
Micro description
=========================================================================
Micro images
=========================================================================
Angiomyxoid lesion with vessels thicker than capillaries
Positive stains
=========================================================================
Differential diagnosis
=========================================================================
Additional references
=========================================================================


Fibroblastic / myofibroblastic tumors
Sclerosing epithelioid fibrosarcoma (SEF)

Reviewer: Cliff Sullivan, M.D. (see Reviewers page)
Editor: Jerad M. Gardner, M.D.
Revised: 9 June 2013, last major update June 2013
Copyright: (c) 2002-2013, PathologyOutlines.com, Inc.

Definition
=========================================================================
Epidemiology
=========================================================================
Sites
=========================================================================
Clinical features
=========================================================================
Prognostic factors
=========================================================================
Case reports
=========================================================================
Treatment
=========================================================================
Gross description
=========================================================================
Gross images
=========================================================================
Lobulaulated, multinodular white mass
Micro description
=========================================================================
Micro images
=========================================================================
Figure 1
Figure 2
Figure 3
Figure 4
Fig 1: Nests of epithelioid cells with clear cytoplasm in a background of dense hyalinized stroma
Fig 2: Cords and strands of epithelioid cells with more eosinophilic cytoplasm within densely collagenized matrix
Fig 3: Cords of epithelioid cells within a eosinophilic hyalinized stroma
Fig 4: Epithelioid cells with angulated nuclei, arranged in cords (single-file pattern) with dense sclerotic background
Alveolar pattern
High power with more cellular appearance
Hemangiopericytoma-like vascular pattern
Cytology description
=========================================================================
Positive stains
=========================================================================
Negative stains
=========================================================================
Electron microscopy description
=========================================================================
Molecular / cytogenetics description
=========================================================================
Differential diagnosis
=========================================================================


Fibroblastic / myofibroblastic tumors
Solitary fibrous tumor (extrapleural)

Reviewer: Ashley Gullett, M.D. (see Reviewers page)
Editor: Jerad M. Gardner, M.D.
Revised: 21 June 2013, last major update June 2013
Copyright: (c) 2002-2013, PathologyOutlines.com, Inc.

Definition
=========================================================================
Clinical features
=========================================================================
Prognostic factors
=========================================================================
Case reports
=========================================================================
Treatment
=========================================================================
Gross description
=========================================================================
Gross images
=========================================================================
Well circumscribed tan-white tumor with focal necrosis
Tumor of omentum
Micro description
=========================================================================
Micro images
=========================================================================

AFIP images:
Figure 1
Figure 2
Figure 3
Fig 1: moderately cellular fibroblastic appearance
Fig 2: parallel arrays of collagen are separated by fibroblastic nuclei
Fig 3: cellular variant has cells with scant cytoplasm and uniform spindled nuclei, note the thin bands of intercellular collagen


Other images:
Patternless pattern and collagenous stroma
Patternless and myxoid patterns with hemangio-pericytoma-like vessels
Fibroblastic cells in fibrous, partly hyalinized matrix with hemangio-pericytoma-like blood vessels

Thigh images:
Epithelioid nodules near fusocellular / spindled areas
Epithelioid and fusocellular areas
With eosinophilic cytoplasm and scarce mitoses
CD34 and BCL2

Case of the week #29 (dermis images):
Virtual slides
=========================================================================
Malignant solitary fibrous tumor
Positive stains
=========================================================================
Negative stains
=========================================================================
Electron microscopy description
=========================================================================
Molecular / cytogenetics description
=========================================================================
Differential diagnosis
=========================================================================
Additional references
=========================================================================


Fibroblastic / myofibroblastic tumors
Superficial acral fibromyxoma

Reviewer: Lauren N. Stuart, M.D., M.B.A. (see Reviewers page)
Editor: Jerad M. Gardner, M.D.
Revised: 15 April 2013, last major update April 2013
Copyright: (c) 2002-2013, PathologyOutlines.com, Inc.

Definition
=========================================================================
Terminology
=========================================================================
Epidemiology
=========================================================================
Sites
=========================================================================
Clinical features
=========================================================================
Prognostic factors
=========================================================================
Case reports
=========================================================================
Treatment
=========================================================================
Gross description
=========================================================================
Micro description
=========================================================================
Micro images
=========================================================================
Tumor at tip of big toe
Spindle cells and mast cells in myxoid matrix
CD34+
CD99+
Spindle cell proliferation
Tumor (fig C/D) compared to myxoid DFSP (fig A/B)
H&E, CD10 and nestin

Positive stains
=========================================================================
Negative stains
=========================================================================
Differential diagnosis
=========================================================================

End of Soft Tissue > Superpage 2


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