ABSTRACT
Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children under 15 years of age. After neuroblastoma and Wilms’ tumor, it is the third most common childhood extracranial solid tumor, and accounts for 60%1 of all childhood sarcomas and 10-15% of all solid pediatric tumors. Approximately 25% of these tumors arise from the genitourinary (GU) tract and another 10% from pelvic or retroperitoneal sites.2-4 Nearly 75% of genitourinary RMS cases are diagnosed before the age of 5 years, with a 3.3:1 male predominance. Since its discovery by Weber in 1854, the clinical and pathologic features of RMS have been studied extensively, thus permitting the development of uniform diagnostic criteria and prognostically relevant staging systems.5
