CASE-REPORT OF A MALIGNANT BRENNER TUMOR WITH HYPERESTROGENISM

A rare malignant Brenner tumor of the ovary presenting with hyperestro genism in a 79 year old woman was examined immunohistochemically and b y light and electron microscopy. High pre-operative serum and urinary estrogen concentrations, low serum luteinizing hormone (LH) and follic le-stimulating hormone (FSH) levels, and histologically confirmed atyp ical endometrial hyperplasia suggested the presence of hyperestrogenis m. The reduction in serum and urinary estrogen and the increase in ser um LH and FSH concentrations after tumor removal confirmed that the tu mor was synthesizing estrogen. Histologically, the malignant element w as predominantly a squamous cell carcinoma, Transitional cell carcinom a was partially found on the cyst wall, There was a spectrum of morpho logic changes between benign and malignant elements with an intermedia te area with a proliferating Brenner tumor. Immunohistochemically, onl y the carcinoembryonic antigen was positive exclusively on the maligna nt element as well as in the microcyst in the benign epithelial cord, whereas all of the markers for germ cell tumors were negative. The ult rastructural features of the stromal cells were of two types: fibrobla sts and steroid-producing cells, The latter type of cells might corres pond morphologically to estrogen-producing cells. The present case is the fourth report showing a malignant Brenner tumor combined with appa rent hyperestrogenism.