[Primary osteosarcoma of the bladder: a case report].

: A case report of primary osteosarcoma of the bladder is herein presented. A 75-year-old man presented with asymptomatic macrohematuria. Cystoscopic examination revealed a large tumor with a broad base arisen on the anterior wall. Pelvic computed tomographic scan showed multiple calcifications in the tumor itself. Total cystectomy and ileal conduit were performed. Histopathological diagnosis was osteosarcoma. The patient died 10 weeks after surgery. Metastasis to lung, heart, lymphnode, ureter and peritoneum were identified by autopsy. Primary osteosarcoma of the bladder is a rare tumor, only 25 cases have been reported previously. The prognosis of this tumor is very poor. Nineteen of these patients died within 6 months.