Rhabdomyosarcoma is a cancerous (malignant) tumor of the muscles that are attached to the bones.
Rhabdomyosarcoma is a cancerous (malignant) tumor of the muscles that are attached to the bones. It can occur in many places in the body. The most common sites are the structures of the head and neck, the urogenital tract, and the arms or legs. Rhabdomyosarcoma is the most common soft tissue tumor in children. The cause of rhabdomyosarcoma is unknown. It is a rare tumor with only several hundred new cases per year throughout the United States. Some children with certain birth defects are at an increased risk, and some families have a gene mutation that elevates risk. However, the great majority of children with rhabdomyosarcoma do not have any known risk factors.