Angiomyofibroblastoma
Differential Diagnosis
The first four entities are predominantly perineal in location and may be confused with angiomyofibroblastoma
Angiomyofibroblastoma |
Aggressive Angiomyxoma |
Most <5 cm |
Nearly always >5 cm |
Well circumscribed |
Not circumscribed |
Alternating hypercellular and hypocellular areas |
Hypocellular |
Clusters of rounded, epithelioid, frequently plasmacytoid cells |
Sparse spindled or stellate cells |
Numerous small vessels |
Large thick walled vessels |
Actin frequently positive |
Actin infrequently positive |
Cases with features of both occur raising the possibility that they form a spectrum.
Size may be a critical distinguishing feature.
Immunohistochemistry reports of actin staining are variable and thus it may not be reliable for separation; both are desmin positive.
Fibroepithelial stromal polyp |
Angiomyofibroblastoma |
Exophytic |
Sessile |
Submucosal |
Subcutaneous |
Poorly circumscribed |
Well circumscribed |
Frequent bizarre stromal cells |
Bland cells |
Both usually contain desmin positive stromal cells
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+.
Perivascular clustering of cells in angiomyofibroblastoma may suggest glomus tumor
Glomus tumor |
Angiomyofibroblastoma |
Very regular round cells |
Spindled and round cells |
Uniform cellularity |
Alternating cellularity |
Actin positive |
Actin variable |
Clusters of epithelioid cells in angiomyofibroblastoma may suggest epithelioid leiomyoma
Epithelioid leiomyoma |
Angiomyofibroblastoma |
Generally more cellular |
Alternating cellularity |
Generally actin positive |
Frequently actin negative |
Both are usually desmin positive