Multifocal sarcoma of the urinary bladder

Sarcomas of the urinary bladder are rare and typically present as solitary, unifocal neoplasms. This is the second report of a primary multifocal sarc oma of the bladder. Like the first reported case, the tumor was highly aggr essive with a short clinical course. The tumor apparently arose in stroma o f the lamina propria and showed a variety of histologic patterns but withou t evidence of differentiation.