Aggressive angiomyxoma: an ultrastructural study of four cases.

The histogenesis of the aggressive angiomyxoma of the vulvo-vaginal region was studied. Four cases of aggressive angiomyxoma were examined by using light microscopy, electron microscopy, and immunohistochemistry. Myofibroblastic from smooth muscle cell differentiation was distinguished by paying close attention to the structures of the neoplastic cell membrane. Aggressive angiomyxomas exhibit subtle features of smooth muscle differentiation, suggesting that the neoplastic cells differentiate from a multipotent perivascular cell.