Osteosarcoma of the bladder--a case report.

A 25-year old man with hematuria had a polypoid tumor of the urinary bladder which was diagnosed as transitional cell carcinoma (TCC) on transurethral resection with partial cystectomy. One year following post-operative radiotherapy, he had to undergo surgery for intestinal perforation. On laparotomy the recurrent tumor had involved pelvic organs and sigmoid colon. It now showed predominantly osteogenic sarcoma on histopathologic examination. The case is reported in view of rarity of primary osteogenic sarcoma in the urinary bladder.