Adenocarcinoma arising from the prostatic duct mimicking transitional cellcarcinoma

A 71-year-old man was first diagnosed with primary transitional cell carcin oma of the prostate with a skip lesion on the distal urethra. The patient r eceived three courses of intra-arterial chemotherapy of cisplatin (CDDP) an d pirarubicin (THP-ADM) followed by a radical prostatectomy. Histopathologi c examination of the prostatectomy specimen revealed adenocarcinoma invasio n along the prostatic duct extending to the peripheral acini, which was dia gnosed as ductal adenocarcinoma. The clinical and histopathologic features of this case are entirely different from usual adenocarcinomas of the prost ate. This rare histopathologic feature should be recognized as 'ductal carc inoma of the prostate', to distinguish it from papillary adenocarcinoma or adenocarcinoma with endometrioid features. The patient has had no sign of r ecurrence 14 months after the operation. CDDP-based chemotherapy followed b y radical prostatectomy may be one of the promising therapeutic modalities for this rare entity.