BACKGROUND: Perivascular epithelioid cell tumors (PEComas) are a rare group of neoplasms composed of epithelioid cells that express both melanocytic and myoid markers. When considering PEComas of the female genital tract, the uterus is the most common location. Involvement of the ovary in the context of a primary uterine PEComa, in the absence of systemic disease associated with tuberous sclerosis, however, has only been reported in 1 previous case.

CASE REPORT: We report a case of a PEComa of the uterus with metastasis to the left ovary in a 61-year-old Caucasian woman. Gross examination of the uterus revealed a 10.7×10.5×10.2 cm tan-brown, mostly solid, partially cystic mass. Microscopic examination showed epithelioid cells with clear to eosinophilic cytoplasm, arranged in fascicles. Intranuclear pseudoinclusions were also noted. The tumor cells were smooth muscle actin, caldesmon, and desmin positive (diffuse); HMB-45 positive (focal); and Melan-A, AE1/AE3, CD10, and S100 negative by immunohistochemistry.

CONCLUSIONS: Distinguishing among mesenchymal neoplasms, including PEComas, endometrial stromal sarcomas, and leiomyosarcomas, can be difficult. Careful analysis of morphologic and immunohistochemical features is of the utmost importance. Differential diagnosis, including morphologic features and immunohistochemical patterns, is also discussed.

Keywords: Ovarian Neoplasms - secondary, Perivascular Epithelioid Cell Neoplasms - secondary, Uterine Neoplasms - pathology