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
- MDM2 and CDK4 negative
- 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
Usually diffuse collagen |
Ropey collagen |
Wispy collagen with prominent round vessels |
Desmin positive |
Desmin negative |
Desmin variable |
Richard L Kempson MD
Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342
Original posting/last update: 5/27/07, 3/14/16