ANGIOMYOFIBROBLASTOMA OF THE VULVA WITH SARCOMATOUS TRANSFORMATION (ANGIOMYOFIBROSARCOMA)

We report on a locally recurrent vulvar tamer in an 80-year-old woman that we believe represents the first example of malignant transformati on of an angiomyofibroblastoma. The tumor was predominantly a typical angiomyofibroblastoma, composed of epithelioid or oval cells with eosi nophilic cytoplasm that tended to cluster in small groups and around b lood vessels. These areas merged imperceptibly with a high-grade sarco ma that resembled a myxoid malignant fibrous histiocytoma. The tumor c ells in the benign areas were diffusely immunoreactive for vimentin; m any cells were positive for smooth muscle actin, and focal positivity for muscle actin and desmin was observed. The tumor cells in the sarco matous areas were diffusely positive for vimentin, but negative for sm ooth muscle actin, muscle actin, and desmin, No staining for keratin, S-100 protein, or CD34 was noted. Ultrastructural examination of the s arcomatous area showed that the cells had the features of fibroblasts. All previously reported cases of angiomyofibroblastoma have exhibited banal histologic features and have behaved in a benign fashion. This case shows that these tumors may rarely be associated with a malignant component, and the designation ''angiomyofibrosarcoma'' may be approp riate in such cases.