Cellular Angiofibroma
Definition
Circumscribed inguinal / perineal mass composed of bland spindled cells will prominent medium sized round vascular component
Alternate / historical names
Angiomyofibroblastoma-like tumor of male genital tract
Diagnostic Criteria
Well circumscribed subcutaneous nodule
May have thin fibrous capsule
Predominantly dermal in 10% of cases
2/51 cases reported with infiltration
Uniform distribution of bland spindle cells
Moderately cellular
Low mitotic rate, usually <1/10 hpf
Occasional findings
Mitotic rate up to 10/10 hpf in 10% of cases
Intranuclear inclusions and nuclear grooves
Vague nuclear palisading
Prominent hyalinized round vessels
Small to medium size
Generally evenly distributed
Staghorn vessels focal about 10% of cases
Fat admixed in 25% of cases
May make up 50% of lesion
Fine collagen bundles
Edematous to fibrous stroma
One series of 13 cases reported with atypia or sarcomatous transformation
(Chen)
Typical areas of cellular angiofibroma present
12/13 female
4 with atypia
Large hyperchromatic cells
3 cases with scattered foci, 1 with a discrete nodule
9 with sarcomatous transformation
2 with pleomorphic liposarcoma
3 resembling atypical liposarcoma
4 with abrupt transition to pleomorphic spindle cells
p16 multifocal or diffuse in atypical cells or sarcomatoid areas
Scattered weak to negative in ordinary cellular fibroma areas
Same behavior so far as usual cellular fibroma
No recurrences or metastases
May form a spectrum with spindle cell lipoma and Mammary Type Myofibroblastoma
All have deletion or rearrangement of 13q14 with loss of nuclear Rb
All are benign
All are CD34 positive with loss of Rb due to 13q14 abnormalities; all are benign
Richard L Kempson MD
Original posting/last update: 5/27/07, 3/14/16
Supplemental studies
Immunohistology
Vimentin
positive
CD34
29/48
Smooth muscle actin
10/48
Desmin
4/48
Estrogen receptor
35%
Progesterone receptor
55%
CD10
2/7
S100
negative
Rb
neg (lost)
(EMA one case reported positive)
p16 multifocal or diffuse in cases with atypical cells or sarcomatoid areas
Scattered weak to negative in ordinary cellular fibroma areas
Differential Diagnosis
The first four entities are predominantly perineal in location and may be confused with cellular angiofibroma
Angiomyofibroblastoma Cellular Angiofibroma
Alternating hypercellular and hypocellular areas
Uniformly moderately cellular
Numerous small vessels
Hyalinized round vessels
Clusters of rounded, epithelioid cells, often around vessels
Bland spindle cells
Desmin positive most cases
Desmin about 10% of cases
Numerous small vessels
Large thick walled vessels
Actin frequently positive
Actin infrequently positive
Both may have fat in lesion, both may be CD34+.
Aggressive Angiomyxoma Cellular Angiofibroma
Usually large, deep lesion
Subcutaneous, mean size 6 cm
Hypocellular
Moderately cellular
Infiltrative margin
Circumscribed
Usually desmin positive
Desmin 10% positive
May infiltrate fat
May have fat integral to lesion
Both have prominent medium sized vessels, both may be CD34+.
Both are superficial and may be CD34 postive. Cellular angofibroma may occur in males.
Mammary-type Myofibroblastoma
Cellular Angiofibroma
Bundles of hyalinized collagen
Wispy collagen
Vessels inconspicuous
Vessels prominent
Desmin and CD34 generally positive
Desmin and CD34 variable
Both may contain adipose tissue
Cellular fibroma is virtually restricted to perineal, genital, inguinal regions, while the entities considered below may occur in a wide variety of sites.
Solitary Fibrous Tumor Cellular Angiofibroma
Alternating cellular and hypocellular areas
Generally uniformly cellular
Staghorn vessels prominent
Hyalinized round vessels prominent
Hyalinized collagen bundles frequent
Wispy collagen frequent
CD34+ nearly all cases
CD34+ 60% of cases
Spindle Cell Lipoma Cellular Angiofibroma
CD34+ nearly all cases
CD34+ 60% of cases
Essentially restricted to neck, upper back
Nearly all inguinal or perineal
Ropy collagen
Wispy collagen
Inconspicuous vessels
Prominent vessels
Fibroepithelial Stromal Polyp
Cellular Angiofibroma
Exophytic
Sessile
May have scattered atypical stromal cells
Uniform cells in most cases
Clinical
Nearly all inguinal / perineal
In females, most vulvovaginal
In males, most inguinal or scrotal
Rare lesions in retroperitoneum, trunk, lumbar region
Even male : female incidence
Age 20-78 years
Female mean 46
Male mean 61
Size 0.6-25 cm, mean 5.7 cm
Subcutaneous 95% of cases
Predominantly dermal in 5%
Recurrences very rare
Metastases not reported
Same behavior reported for cases with atypical cells or sarcomatous transformation
Grading / Staging / Report
Grading and staging are not applicable
The surgical pathology report should contain or address the following:
Location
Type of resection or biopsy
Histologic diagnosis
Managerial category Ia (Local excision is almost always curative; metastasis never occurs)
Size
Depth (dermis, subcutis, below fascia, body cavity)
Margins
Results of supplementary studies if performed
Relationship to other specimens from the same patient
Lists
Vulvovaginal stromal and spindled tumors
Lesions that may demonstrate a prominent hemangiopericytoma-like vascular pattern
Bibliography
Kempson RL, Fletcher CDM, Evans HL, Henrickson MR, Sibley RS. Tumors of the Soft Tissues, Atlas of Tumor Pathology, AFIP Third Series, Fascicle 30, 2001
Fletcher CDM, Unni KK, Mertens F. Pathology and Genetics of Tumours of Soft Tissue and Bone, World Health Organization Classification of Tumours 2002
Weiss SW, Goldblum JR. Enzinger and Weiss's Soft Tissue Tumors, 4th edition, 2001
Iwasa Y, Fletcher CD. Cellular angiofibroma: clinicopathologic and immunohistochemical analysis of 51 cases. Am J Surg Pathol. 2004 Nov;28(11):1426-35.
McCluggage WG, Ganesan R, Hirschowitz L, Rollason TP. Cellular angiofibroma and related fibromatous lesions of the vulva: report of a series of cases with a morphological spectrum wider than previously described. Histopathology. 2004 Oct;45(4):360-8.
Nucci MR, Granter SR, Fletcher CD. Cellular angiofibroma: a benign neoplasm distinct from angiomyofibroblastoma and spindle cell lipoma. Am J Surg Pathol. 1997 Jun;21(6):636-44.
Laskin WB, Fetsch JF, Mostofi FK. Angiomyofibroblastomalike tumor of the male genital tract: analysis of 11 cases with comparison to female angiomyofibroblastoma and spindle cell lipoma. Am J Surg Pathol. 1998 Jan;22(1):6-16.
Chen E, Fletcher CD. Cellular angiofibroma with atypia or sarcomatous transformation: clinicopathologic analysis of 13 cases. Am J Surg Pathol. 2010 May;34(5):707-14.
