Angiomyofibroblastoma of the vulva: report of a case.

A case of solitary angiomyofibroblastoma of the vulva in a 16-year-old woman was examined by histology and immunohistochemistry. Microscopic examination of the tumor revealed typical features of a mesenchymal neoplasm, composed of bundle spindle cells with low cellular density, rich in collagen fibers and thin-walled blood vessels. Immunohistochemistry revealed immunoreactivity for progesterone receptor, CD34, desmin and vimentin, tumor cells expressing positivity, but not for estrogen receptors. The stains for the muscle-specific actin and S-100 were negative. These results were mostly consistent with those of previous reports and suggest that the tumors cells were derived from primitive mesenchymal cells which occur normally in this region and show the potential for diverse lines of myoid differentiation.