ANGIOMYOFIBROBLASTOMA OF THE VULVA - A MITOTICALLY ACTIVE VARIANT

A case of angiomyofibroblastoma in a 48-year-old woman is reported. Th e tumor occurred as a left vulval mass and was treated by simple excis ion. It was located in the subcutaneous tissue of the left vulva and w as well circumscribed, measuring 2.8 x 2.7 x 2.5 cm. Microscopically, the tumor was composed of hypocellular and cellular areas with well-de veloped small vessels. Spindle or polygonal cells were arranged with p erivascular accentuation in an edematous or fibrocollagenous backgroun d. Some spindle-shaped or polygonal stromal cells were also arranged i n epithelioid nests, in some areas, mitoses were frequent (maximum 3/1 0 high-power field). Immunohistochemically, the stromal cells were pos itive for vimentin and desmin, but negative for a-smooth muscle actin, S-100, neurofilament, estrogen receptor, progesterone receptor, CD31 and CD34. The average labeling index of Ki-67 in stromal cells was 3.1 %. Ultrastructural analysis demonstrated that the stromal cells adhere d with primitive junctions and contained intermediate filaments with n o focal density in the cytoplasm. These findings were consistent with angiomyofibroblastoma, although previously reported cases did not show so many mitoses. Therefore, this case was suggested to be a mitotical ly active variant.