[Signet ring-cell carcinoma of the prostate: a case report]

A 76-year-old male was admitted with a complaint of dysuria. Serum prostatic specific antigen was 28 ng/ml. Transperineal prostatic biopsy was performed and histopathological diagnosis was signet ring cell carcinoma with a part of poorly differentiated adenocarcinoma. Imaging studies showed that the tumor was localized in a large part of the prostate, and no abnormality was found in the stomach, the intestine, or the colon. Cystoprostatectomy and ileal conduit construction were performed in November 2002. Immunohistochemistry revealed that the specimen included the signet ring cells, which were stained for prostate specific antigen antibody, but not with periodic acid schiff. He is alive with no evidence of disease in 13 months after the operation.