Perianal rhabdomyosarcoma: report of a case in an infant.

Rhabdomyosarcoma is the most common childhood sarcoma, whereas, primary pararectal rhabdomyosarcoma is very rare. To date, four pediatric and eight adult cases have been reported. In children, the tumor presents as a perianal polypoid mass, often initially misdiagnosed. Formerly a very lethal sarcoma, rhabdomyosarcoma is now treated with combined surgery, radiation, and chemotherapy, with encouraging results.