Case ReportsTubulocystic Clear Cell Adenocarcinoma Arising Within the ProstatePan, Chin-Chen M.D.; Chiang, Hung M.D.; Chang, Yen-Hwa M.D., Ph.D.; Epstein, Jonathan I. M.D.Author Information From the Department of Pathology (C.-C.P., H.C.), the Division of Urology (Y.-H.C.), National Yang-Ming University and Veterans General Hospital-Taipei, Taiwan, R.O.C.; and the Department of Pathology and the James Buchanan Brady Urological Institute (J.I.E.), The Johns Hopkins Medical Institutions, Baltimore, Maryland, U.S.A. Address correspondence and reprint requests to Chin-Chen Pan, MD, Department of Pathology, Veterans General Hospital-Taipei, No.201, Sec. 2, Shih-Pai Rd., Taipei, 11217, Taiwan, R.O.C.; e-mail: [email protected] The American Journal of Surgical Pathology: October 2000 - Volume 24 - Issue 10 - p 1433-1436 Buy Abstract Neoplasms resembling ovarian common epithelial-type tumors, including clear cell adenocarcinomas, rarely occur in the lower urinary tract of men. When they do, they develop in the urethra or urinary bladder. We report a case of such a tumor arising within the prostate of a 47-year-old man. The tumor was a cystic mass in the left posterolateral region of the prostate. Histologically, the tumor was chiefly composed of tubulocystic and papillary glands lined by glycogen-rich, cuboidal or hobnail cells with clear to eosinophilic cytoplasm. The tumor cells were strongly positive for pan-cytokeratin, low molecular weight cytokeratin, and epithelial membrane antigen, and focally positive for high molecular weight keratin. The tumor did not immunohistochemically express prostate-specific antigen (PSA) and prostatic acid phosphatase. Serologically, the patient had increased levels of CA125 instead of PSA. The clinical as well as the pathologic features are consistent with a clear cell adenocarcinoma as seen in the female genital tract rather than a typical prostatic adenocarcinoma. © 2000 Lippincott Williams & Wilkins, Inc.