A case of HMB45-negative perivascular epithelioid cell tumor (PEComa) of the uterine corpus: a possible diagnostic application of molecular-cytogenetic analysis.

We report a case of uterine angiomyolipoma confirmed with molecular-genetic analysis by fluorescence in situ hybridization (FISH). A 25-year-old nulliparous woman visited Yamaguchi University Hospital with a complaint of lower abdominal pain. Magnetic resonance imaging demonstrated an ill-bordered uterine tumor and exploratory laparotomy revealed a myometrial elastic-soft tumor at the anterior wall of the uterine corpus. Histopathologically, the tumor consisted of fascicles of smooth muscle cells with intermingled adipocytes and small to medium-sized arterial blood vessels surrounded by epithelioid cells of clear cytoplasm. FISH examination revealed chromosome X trisomy, which was comparable to a previously reported molecular-genetic finding of PEComa family tumors including angiomyolipoma. Although the tumor was immunohistochemically negative for HMB-45 antigen, the histological and FISH findings were compatible with angiomyolipoma.