[Case of malignant lymphoma of the prostate complicated with prostate adenocarcinoma].

A 68-year-old man was referred to our hospital with complaints of palpation, hematemesis and melena. Esophagogastroduodenoscopy revealed a huge ulcer in the stomach, and based on biopsy findings, he was pathologically diagnosed as having diffuse large B-cell type malignant lymphoma. A computed tomographic scan demonstrated prostatic enlargement and swelling of the left external iliac lymph nodes. Since his serum PSA level was 13.0 ng/ml, prostatic needle biopsy was performed. Histological findings revealed diffuse large B-cell type malignant lymphoma and moderately differentiated adenocarcinoma of the prostate. The patient achieved complete response after eight cycles of combination chemotherapy with rituximab cyclophosphamide, adriamycin, vincristine and predonisolone. At the same time of chemotherapy, androgen deprivation therapy was initiated. The current his PSA level is 0.2 ng/ml or less.