Poorly differentiated sarcoma of the prostate causing obstructive acute renal failure: a case report.

A 12-year-old boy presented to the Naha Municipal Hospital complaining of back pain. After intravenous pyelography, computed tomography, magnetic resonance imaging, ultrasonography and biopsy, he was suspected to have sarcoma of the prostate and was referred to the University of the Ryukyus Hospital. Acute renal failure of the post renal type was evident, accompanied by minimal hydronephrosis. Emergency hemodialysis and right ureterostomy were performed, as was a transurethral prostate biopsy. The specimen showed a poorly differentiated sarcoma not otherwise classifiable. After recovery from surgery, chemotherapy was attempted over 2 months, but the patient died of tumor 250 days after admission.