[A case of giant small cell carcinoma of the prostate].

A 64-year-old man having backbone pain was referred to our institute, and laboratory examinations revealed that he was suffering from severe renal failure. Abdomino-pelvic CT revealed bilateral hydronephrosis, a giant prostate over 500 g in weight, and multiple para-aortic lymph node metastasis. Histological diagnosis of the prostate was small cell neuroendocrine carcinoma. Serum neuron-specific enolase (NSE) level was slightly high reflecting the positive immunohistochemical staining, but serum PSA remained within normal limits. The patient was treated with hormone-chemotherapy after successful treatment of the renal failure, but he died on the 74th hospital day. Small cell carcinoma is known to have a high rate of malignancy and metastasis from an early stage. Several giant prostatic tumors have been reported previously, but this case is considered to be the second gigantic small cell carcinoma in the Japanese literature.