Perivascular epithelioid cell tumor of abdominal origin.

Perivascular epithelioid tumor is not a common disease; therefore, large series are not available in the literature, and most are case reports. Histologic characteristics of these neoplasms are positivity to melanogenic (HMB-45) and muscle stains. All these neoplasms have the characteristic perivascular epithelioid cell or "PEC," but the term myomelanocyte tumor has been proposed because of the immunohistochemistry expression. Females are affected more commonly than males. The uterus seems to be one of the most common organs affected. Its clinical behavior is uncertain, and standard treatment has not been established as well as criteria for malignancy. We report 3 cases of abdominal PEComa, 1 of them with benign clinical outcome and 2 with an aggressive behavior.