[A case of papillary adenocarcinoma of the prostate which was difficult to diagnose]

We report a case of papillary adenocarcinoma of the prostate found by urethroscopy. An 84-year-old male visited our hospital complaining of initial hematuria in July 1997. No abnormal findings were detected despite repeated urological examinations until endoscopic examination revealed fine papillary tumors in the prostatic urethra along with benign prostatic hyperplasia-like prominent left lobe of the prostate in June 2000. Serum prostate specific antigen (PSA) level was 4.1 ng/ml. He underwent transurethral resection of the urethral tumors and the prominent lobe, which was found to contain packed papillary tumors. Both of these tumors were well differentiated papillary adenocarcinoma most likely originating from the prostate because PSA immunostaining was positive. The prostate was irradiated postoperatively. Papillary adenocarcinoma localized in the prostate is difficult to diagnose preoperatively.