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Skin - Nonmelanocytic tumors

Reviewer: Christopher Hale, M.D. (see Reviewers page)
Revised: 18 September 2012, last major update September 2012, UPDATE IN PROGRESS
Copyright: (c) 2001-2012, PathologyOutlines.com, Inc.

Table of contents

Primary references

Benign (nonmelanotic) epidermal tumors or tumor-like lesions: acquired digital fibrokeratoma† †clear cell papulosis† †cutaneous horn† †fibroepithelial polyp† †hair follicle nevus† †large cell acanthoma† †melanoacanthoma† †pseudoepitheliomatous hyperplasia† †seborrheic keratosis† †verruca vulgaris† †verrucous hyperplasia

Cysts: apocrine cystadenoma† †apocrine hidrocystoma† †bronchogenic cyst† †cystadenoma† †dermoid cyst† †keratinous cyst† †pigmented follicular cyst† †steatocystoma† †vellous hair cyst

Adnexal tumors: general

• apocrine glands: general† †apocrine mixed tumor† †apocrine tubular adenoma† †hidradenoma papilliferum

• eccrine sweat glands: acrosyringeal adenomatosis† †aggressive digital papillary adenoma† †chondroid syringoma† †clear cell acanthoma† †cutaneous lymphadenoma† †eccrine acrospiroma† †eccrine cylindroma† †eccrine poroma† †eccrine spiradenoma† †intraepidermal epithelioma† †microcystic adnexal carcinoma† †mucinous carcinoma† †myoepithelioma† †myoepithelial carcinoma† †papillary eccrine adenoma† †sweat gland carcinoma† †syringocystadenoma papilliferum† †syringoma / syringomatous carcinoma

• hair follicles: folliculofibroma† †inverted follicular keratosis† †keratinous cyst† †keratoacanthoma† †pilar tumor† †pilomatrixoma† †trichilemmoma† †trichoepithelioma† †trichofolliculoma† †warty dyskeratoma

• sebaceous glands: senile sebaceous hyperplasia† †nevus sebaceus of Jadassohn† †sebaceous adenoma† †sebaceous carcinoma

Premalignant / in situ: carcinoma in situ-general† †actinic keratosis† †bowenoid papulosis† †Bowenís disease† †Pagetís disease

Carcinoma (non adnexal): adenoid cystic carcinoma† †adenoid squamous cell† †adenosquamous† †basal cell† †lymphoepithelioma-like† †Merkel cell† †Merkel-staging† †metastatic† †mucoepidermoid† †small cell† †spindle squamous cell† †squamous cell† †verrucous carcinoma† †staging

Lymphoma and related disorders: general† †acute lymphoblastic† †anaplastic large cell† †angiocentric† †blastic plasmacytoid† †diffuse large B cell† †follicular† †Hodgkin† †HTLV-1† †intravascular† †Jessnerís lymphocytic infiltration of skin† †leukemia† †lymphoid hyperplasia† †lymphomatoid papulosis† †MALT† †mantle zone† †mast cell disorders† †mycosis fungoides† †NK/T cell† †peripheral T cell† †primary cutaneous (general)† †Woringer-Kolopp disease

Vascular tumors: acquired angioma† †angiokeratoma† †angiosarcoma† †bacillary angiomatosis† †benign lymphangioendothelioma† †glomus† †hemangioma† †hemangioendothelioma† †infantile (benign) hemangioendothelioma† †intravascular papillary endothelial hyperplasia† †Kaposiís sarcoma† †Kimuraís disease† †lymphangioma† †pyogenic granuloma† †reactive angioendotheliomatosis† †vascular leiomyoma† †verruga peruana

Other tumors of skin: angiofibroma† †atypical fibrous histiocytoma† †atypical fibroxanthoma† †benign cystic teratoma† †benign fibrous histiocytoma (superficial)† †collagenous fibroma† †connective tissue nevus† †deep benign fibrous histiocytoma† †dermatofibrosarcoma protuberans† †dermatomyofibroma† †endometriosis† †epithelial sheath neuroma† †granular cell tumor† †hamartoma of scalp† †histiocytoma† †inclusion body fibromatosis† †inflammatory pseudotumor† †keloid† †Langerhans cell histiocytosis† †leiomyoma† †leiomyosarcoma† †malignant fibrous histiocytoma† †malignant peripheral nerve sheath tumor (MPNST)† †meningioma† †meningioma-like tumor of skin† †multicentric reticulohistiocytosis† †neurofibroma† †neurothekeoma† †palisaded encapsulated neuroma† †perineurioma† †pleomorphic fibroma† †schwannoma† †sclerosing fibroma† †sinus histiocytosis with massive lymphadenopathy† †striated muscle hamartoma† †supernumerary digit† †xanthoma† †xanthogranuloma

Go to Skin-Nontumor chapter
Go to Skin Tumor - Melanocytic chapter

Primary references


AJCC Cancer Staging Manual (7th ed)
American Journal of Clinical Pathology
American Journal of Surgical Pathology
Archives of Pathology and Laboratory Medicine
Human Pathology
Modern Pathology

Please refer to these primary references for more detailed discussions and photographs

Other tumors of skin

Atypical fibroxanthoma [AFX]


Definition: dermal variant of MFH-pleomorphic with low grade behavior

Also called intermediate fibrous histiocytoma

See also Ear chapter

Rapidly growing dome-shaped or polypoid nodule on sun-damaged areas of head and neck of elderly

Rarely presents as large mass in limb or trunk of younger individuals, or post radiation therapy

May clinically resemble carcinoma

Must exclude tumors with AFX like patterns, other lines of differentiation, significant involvement of subcutis, necrosis, vascular invasion or infiltrative margins

Poor prognostic indicators: history of immunosuppression, recurrence

Case reports: 81 year old woman with lower leg lesion (Dermatology Online Journal 14(1)), 63 year old man with metastatic tumor from eyebrow area to face (Archives 2006;130:735), 81 year old man with widespread peritoneal metastases (AJSP 2006;30:1041)

Treatment: local excision; rarely recurs or metastasizes

Gross: polypoid, ulcerated, usually small

Gross images: irregular polypoid tumor

Micro: bizarre tumor cells in hypercellular, spindly stroma with frequent mitotic figures, many atypical; also smaller fibroblastic, myofibroblastic and histiocyte-like cells with pleomorphism and angulated nuclei; histologically identical to MFH-pleomorphic but centered in dermis; background stroma appears inflammatory or reactive; pushes aside surrounding pilosebaceous units and eccrine glands; typically does not involve epidermis or subcutaneous tissue; no grenz zone; lacks classic features of fibrous histiocytoma (entrapped hyalinized collagen bundles and epidermal hyperplasia); no necrosis, no vascular invasion, no infiltrative margins

variants: clear cell (J Cutan Pathol 2006;33:343), granular cell (Am J Dermatopathol 2007;29:84)

Micro images: exophytic cellular nodule with ulcerationfascicles of atypical spindle cellstumor is limited to dermis but otherwise resembles MFH-pleomorphic with marked cellularity, prominent pleomorphism, mitotic figures and clumped chromatinmarked cellularity and pleomorphismcharacteristic bizarre cellsspindle variant has less pleomorphismspindle and epithelioid cells with atypiaulcerated tumor #1#2#3#4#5nodular spindle cell tumor #1;  #281 year old woman with lower leg lesionfig A: edge of lesion shows hyperchromatic cells next to elastotic dermis (arrow), fig B/C: atypical spindle cells and histiocytes, atypical mitotic figure (arrow), fig D: alpha-1-antichymotrypsin positivefigure 1: eyebrow primary, figures 2-4: facial metastasis (fig 4 is CD68)Factor XIIIap53

contributed by Dr. Angel Fernandez-Florez, Hospital El Bierzo, Spain - #1#2#3CD68CD117CD10AE1-AE3

Positive stains: vimentin, CD68, alpha-1-antitrypsin, alpha-1-antichymotrypsin, Factor XIIIa (focal), CD117 (Am J Dermatopathol 2008;30:34), CD99 (73%, AJCP 2002;117:126), CD10 (Australas J Dermatol 2005;46:235), calponin (30%, Virchows Arch 2002;440:404), desmin (30%), smooth muscle actin (30%)

Negative stains: keratin, EMA, S100 (although S100+ Langerhans cells may be present), HMB45 (rarely positive, J Cutan Pathol 2004;31:284), caldesmon

EM: myofibroblasts, fibroblasts and primitive mesenchymal cells

Molecular: diploid

DD: squamous cell carcinoma-spindle cell type; desmoplastic melanoma (may have focal AFX-type features and stain negative for melanocytic markers, Am J Dermatopathol 2007;29:551), atypical fibrous histiocytoma

References: eMedicine

Collagenous fibroma


Also called desmoblastic fibroblastoma

Subcutaneous lesion, often with fascial involvement

Micro: bland stellate and spindled fibroblasts with collagenous or myxoid matrix

Deep benign fibrous histiocytoma


Definition: benign fibrous histiocytoma of subcutaneous tissue, deep soft tissue or parenchymal organs, with no dermal involvement

Rare, <1% of fibrohistiocytic tumors

Usually adult males > 25 years

Head and neck and lower limb

Treatment: excision; may recur if incompletely excised, rare metastases

Gross: well circumscribed with pseudo-capsule, typically 4 cm, variable hemorrhage

Micro: prominent storiform pattern of uniform spindle cells with ill defined eosinophilic cytoplasm and bland, elongated or plump vesicular nuclei with no atypia; often hemangiopericytoma-like vasculature; scattered lymphocytes, either multinucleated giant cells, osteoclastic giant cells or foam cells in 59%; usually less than 5 mitotic figures/10 HPF; stroma is myxoid or hyaline; borders are non-infiltrative, with no trapping of fat cells; necrosis or angiolymphatic invasion are rare

Micro images: circumscribed tumor with no trapped fatcellular tumortumor with more fibrous stromafoam cells help distinguish from DFSPfocal storiform pattern and cellular uniformityhemangiopericytoma-like vascular pattern #1#2 

Positive stains: CD34 (40%), smooth muscle actin (38%)

Negative stains: keratin, EMA, desmin, S100

DD: solitary fibrous tumor, dermatofibrosarcoma protuberans (DFSP) (not circumscribed, usually infiltrative borders, little cellular heterogeneity, usually no foam cells, CD34+, Factor XIIIa negative, Semin Cutan Med Surg 1999;18:91)

References: AJSP 2008;32:354, AJSP 1994;18:677, AJSP 1990;14:801

End of Skin - Nonmelanocytic tumors chapter