Vulval angiomyofibroblastoma. Clinicopathologic analysis of six cases.

Clinicopathologic, immunohistochemical, ultrastructural, and flow cytometric analyses were performed on vulvar angiomyofibroblastomas in six women (ages 32 to 46 years; average age, 41.3 years). The tumors were all well circumscribed, and measured 2 to 9 cm in greatest dimension. Five tumors were clinically diagnosed as Bartholin's gland cysts. At histologic analysis, the tumors were characterized by alternating hypercellular and hypocellular edematous areas with abundant blood vessels. The hypercellular areas showed a perivascular proliferation of spindle-shaped and round cells, which often formed small nests or epithelioid arrangements, and a short fascicular pattern of spindle cells. The proliferating vessels were thin-walled and capillary-sized. Cellular atypia and mitotic figures were absent. Two tumors contained an adipose element, and one showed a prominent vascular proliferation reminiscent of a capillary hemangioma. At immunohistochemical analysis, the tumor cells were strongly positive for vimentin and desmin. Some cells were weakly positive for HHF35 and alpha-smooth muscle actin. Ultrastructurally, one neoplasm showed fibroblastic differentiation. Flow cytometry revealed three tumors were DNA diploid and two were aneuploid. All tumors were excised, and none have recurred (average follow-up, 28.3 months). These results indicate that angiomyofibroblastomas contain heterogeneous components.