Soft tissue

Fibroblastic / myofibroblastic

Angiofibroma of soft tissue



Last author update: 17 October 2022
Last staff update: 17 October 2022

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PubMed Search: Angiofibroma of soft tissue

Rabia Ahmed, M.B.B.S.
Nasir Ud Din, M.B.B.S.
Page views in 2022: 6,894
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Cite this page: Ahmed R, Anjum S, Ud Din N. Angiofibroma of soft tissue. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/softtissueangiofibroma.html. Accessed February 3rd, 2023.
Definition / general
  • Benign fibroblastic neoplasm of uniform spindle cells
  • Variable myxoid and collagenous stroma with a network of thin walled, branching blood vessels
Essential features
  • Clinically well defined mass located in the soft tissues of the extremities, often in association with joints or fibrotendinous structures
  • Histologically uniform spindle cells, myxoid / collagenous stroma, network of thin walled, branching blood vessels
  • Cytogenetically NCOA2 gene rearrangements
ICD coding
  • ICD-O: 9160/0 - angiofibroma, NOS
  • ICD-11: EE6Y & XH1JJ2 - other specified fibromatous disorders of skin and soft tissue & angiofibroma, NOS
Epidemiology
Sites
Pathophysiology
Etiology
  • Unknown
Clinical features
Diagnosis
  • Requires interpretation of clinical, radiological and histopathological findings
Radiology description
  • MRI
    • Limited descriptions of the appearance of angiofibroma of soft tissue on imaging
    • A few reports have described it as a well circumscribed mass
    • Signal characteristics and enhancement are presumed to be variable, subject to the cellular, myxoid, collageneous and vascular content of the lesion
    • T1: roughly isointense to skeletal muscle; T2: heterogeneous high signal intensity; T1C+ (Gd): variable from homogeneous to a peripheral enhancement (Mol Clin Oncol 2017;7:229)
Radiology images

Contributed by Nasir Ud Din, M.B.B.S.
Angiofibroma of ankle Angiofibroma of ankle

Angiofibroma of ankle

Angiofibroma of distal leg

Angiofibroma of distal leg



Images hosted on other servers:
MRI vastus lateralis muscle

MRI vastus lateralis muscle

Prognostic factors
  • Angiofibroma of soft tissue pursues a benign clinical course
  • Rare local recurrence and no evident metastatic potential
Case reports
Treatment
Clinical images

Images hosted on other servers:
Arthroscopic view angiofibroma knee

Arthroscopic view of knee

Gross description
  • Well demarcated, nodular or multinodular solid tumor
  • Infiltration of the surrounding tissues does occur
  • Range in size from 1.2 to 10.0 cm (mean 5.1 cm)
  • White to yellow, often glistening cut surface
  • Cystic or hemorrhagic areas may be present (Genes Chromosomes Cancer 2017;56:750)
Microscopic (histologic) description
  • Well circumscribed
  • Vaguely lobulated architecture
  • Alternating myxoid and collagenous areas
  • Regional variation in cellularity (Genes Chromosomes Cancer 2017;56:750)
  • Uniform bland spindle cells
  • Prominent vascular network
  • Spindle cells have inconspicuous palely eosinophilic cytoplasm
  • Short ovoid or tapering nuclei, irregular nuclear contours, fine chromatin and indistinct nucleoli
  • Cytological atypia and nuclear hyperchromasia are generally absent
  • Vascular network is composed of innumerable small, thin walled blood vessels evenly distributed throughout the lesion
  • Less prominent medium or large sized blood vessels with variably thick walls are usually present (Am J Surg Pathol 2012;36:500)
  • Perivascular collagen deposition and marked hyalinization or fibrinoid necrosis of medium sized vessel walls
  • Occasional degenerative atypia (Am J Surg Pathol 2012;36:500)
  • Degenerative changes may be focally present, including chronic inflammation, hemorrhage and aggregates of foamy histiocytes (Histopathology 2016;69:459)
  • Variably dense infiltrate of lymphocytes, sometimes perivascular in distribution
Microscopic (histologic) images

Contributed by Nasir Ud Din, M.B.B.S.
Diffuse spindle cells and vascular network

Diffuse spindle cells and vascular network

Variable cellular areas of spindle cells

Variable cellular areas of spindle cells

Hypo and hypercellular area of the lesion

Hypocellular and hypercellular area of the lesion

Hypocellular area

Hypocellular area

Spindle cells with thin vascular network

Spindle cells with thin vascular network


Thin walled blood vessels

Thin walled blood vessels

Spindle cell neoplasm with occasional ectatic vessels

Spindle cell neoplasm with occasional ectatic vessels

Extracellular collagenous matrix

Extracellular collagenous matrix

Collagenous stroma Collagenous stroma

Collagenous stroma


Network of thin walled blood vessels

Network of thin walled blood vessels

Variable cellularity and edema

Variable cellularity and edema

Edematous area Edematous area

Edematous area

CD34

CD34



Contributed by Komal Arora, M.D. (Case #311)
Circumscribed spindle cell tumor Circumscribed spindle cell tumor

Circumscribed spindle cell tumor

Spindle cells in collagenous stroma Spindle cells in collagenous stroma

Spindle cells in collagenous stroma


Spindle cells with thin vasculature Spindle cells with thin vasculature

Spindle cells with thin vasculature

Spindle cells in myxoid stroma

Spindle cells in myxoid stroma

Positive stains
Molecular / cytogenetics description
Molecular / cytogenetics images

Images hosted on other servers:
FISH revealing NCOA2 rearrangement

FISH revealing NCOA2 rearrangement

Videos

Angiofibroma of soft tissue

Sample pathology report
  • Soft tissue, thigh, excision:
    • Angiofibroma of soft tissue (see comment)
    • Comment: The sections reveal a fibroblastic neoplasm composed of uniform spindle cells in a variable myxoid and collagenous stroma with a network of innumerable small, thin walled, branching blood vessels. No necrosis, marked cytologic atypia or significant mitotic activity is identified. It is positive for CD34 and EMA on immunohistochemistry. These support the above diagnosis.
Differential diagnosis
  • Cellular angiofibroma:
    • Usually occurs in the pelviperineal region
    • More uniformly cellular
    • Vessels are more rounded having hyalinized walls
    • Usually ER+, PR+; loss of RB1
  • Solitary fibrous tumor:
    • Fibroblast-like cells with patternless appearance
    • Thick bands of collagen and prominent branching, hyalinized vessels
    • CD34+, CD99+, STAT6+
    • STAT6 rearrangement
  • Low grade fibromyxoid sarcoma:
    • Alternating myxoid and collagenous areas and whorled growth pattern
    • Arcades of thin wall blood vessels
    • 33% of cases contain giant collagen rosettes
    • EMA+, MUC4+
    • FUS::CREB3L2 fusion in most
  • Low grade myxofibrosarcoma:
    • Lobulated growth pattern, myxoid background, infiltrative borders
    • Long curvilinear vessels with perivascular hypercellularity
    • Cells have pleomorphic hyperchromatic nuclei and mitoses
  • Myxoid liposarcoma:
    • Prominent chicken wire vasculature
    • Numerous signet ring lipoblasts particularly at periphery of lobules
    • Mucoid matrix rich in hyaluronidase sensitive acid mucopolysaccharides; may have large mucoid pools
    • DDIT3 rearrangement
Board review style question #1
A 40 year old woman presented with a slowly growing mass on left thigh. Grossly, the tumor was well circumscribed with yellow-white cut surface. Microscopically, the tumor showed numerous small, branching, thin walled blood vessels in a collagenous and myxoid stroma. On immunohistochemistry, the tumor cells showed positivity for CD34 and EMA. What is the most likely diagnosis?

  1. Angiofibroma of soft tissue
  2. Cellular angiofibroma
  3. Low grade fibromyxoid sarcoma
  4. Myxofibrosarcoma
  5. Myxoma
Board review style answer #1
A. Angiofibroma of soft tissue. It is a fibroblastic neoplasm that commonly arises in lower extremities, often in relation to joints or fibrotendinous structures of middle aged females. It is composed of uniform spindle cells in a variable myxoid and collagenous stroma with a network of innumerable small, thin walled, branching blood vessels. It is positive for CD34 and EMA on immunohistochemistry.

Comment Here

Reference: Angiofibroma of soft tissue
Board review style question #2

A 55 year old woman presented with a mass on lateral aspect of left ankle for last 5 years. MRI revealed a well demarcated, enhancing, round mass that measured 4 cm. Excision biopsy was performed and microscopic examination revealed a lesion in given photomicrograph. Which cytogenetic aberration is associated with this tumor?

  1. AHHR::NCOA2
  2. FUS::CREBB3L2
  3. FUS::DDIT3
  4. NAB2::STAT6
  5. RB1 / FOXO1 deletion
Board review style answer #2
A. AHHR::NCOA2. The photomicrograph shows a tumor composed of uniform spindle cells in a variable myxoid and collagenous stroma with a network of innumerable small, thin walled, branching blood vessels, characteristic of angiofibroma of soft tissue. It is associated with NCOA2 rearrangement or AHRR::NCOA2 fusion gene in most cases.

Comment Here

Reference: Angiofibroma of soft tissue
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