ADENOMAS OF THE RETE OVARII

This article reports the clinicopathological and immunohistochemical f indings of two cases of adenoma of the the rete ovarii (RO), one unila teral and the other bilateral, presenting with atypical histological f eatures in the right ovary. Both tumors were incidental findings in 62 - and 64-year-old patients presenting with metrorrhagia. The predomina ntly cystic lesions measured 2 cm and 3 cm in diameter and microscopic ally, they were tubulopapillary proliferations of regular columnar cel ls with clear cytoplasm. The stroma showed extensive differentiation o f polygonal, Leydig-like cells which was associated in both cases with simple endometrial hyperplasia. In both cases rete and hilar mesoneph ric remnants were found in the vicinity of the lesion. The atypical le sion in one case had a complex papillary proliferation different in pa ttern and cellularity from a retiform Sertoli-Leydig cell tumor. It sh owed extensive areas of eosinophilic change, pleomorphism, and a few m itoses but did not invade the adjacent ovarian stroma. Its stroma also had steroidally active cells. The patient was alive and well after a follow-up interval of 3 years. Immunohistochemically, the lesions were diffusely positive for CAM 5.2, vimentin, epithelial membrane antigen , OC 125, OC 125, and progesterone receptors. Copyright (C) 1997 by W. B. Saunders Company.