Perivascular Epithelioid Cell Tumor: A Case Presenting as a Paratubal Pelvic Mass

초록

Perivascular epithelioid cell tumor (PEComa) is a rare mesenchymal tumor histologically characterized by diffuse, nested and/or fascicular proliferation of spindled and epithelioid cells. Although PEComas can be confused with smooth muscle tumors, either spindled or epithelioid, PEComas more often exhibit pale eosinophilic to clear cytoplasm, round to oval nuclei, and a prominent capillary network. The tumor cells in Type A usually show a tongue-like growth pattern, with diffuse HMB-45 expression and focal smooth muscle reactivity. The tumor cells in Type B tumors show extensive muscle marker expression and a lesser degree of tongue-like growth pattern, with only a minor population of tumor cells being HMB-45 positive. The recognition of characteristic vascular pattern and peritheliomatous cells with myomelanocytic differentiation is prerequisite for correct pathologic diagnosis. We present a case of PEComa with presenting as a paratubal pelvic mass. The patient was a 54-year old premenopausal woman presenting with a slowing growing pelvic mass that displayed prominent stromal hyalinization. Key Words: Pelvic Neoplasms, Perivascular Epithelioid Cell, HMB45