Angiofibroma-like perineurioma. Report of a case.

We report an unusual perineurioma with numerous vessels, showing a strong similarity with angiofibroma. A 2,5 x 2 x 2 cm subcutaneous/dermal tumor occurred in 58-ys-old male in the left brachial region. Histologically, it was composed of haphazardly arranged bland spindle cells and it contained prominent vasculature. In rare foci, the tumor cells showed thin bipolar processes and an onion-like perivascular whorling pattern. Immunohistochemically, expression of perineural cell markers EMA, claudin-1 and CD34 was limited to perivascular foci and to rare cells among the vessels. In addition, the tumor expressed CD10 diffusely. Our finding indicates that diagnosis of perineurioma should be considered also by tumors with an "angiofibromatous" morphology. Especially soft tissue angiofibroma, which often express EMA (perineural cell marker), shows a strong resemblance to angiofibroma-like perineurioma.