Sonographic evaluation of pediatric rhabdomyosarcomas.

The ultrasound examinations of ten pediatric patients with retroperitoneal or pelvic embryonal rhabdomyosarcomas were reviewed. A pattern of coarse low-, medium-, or high-level echoes was observed in these tumors. Sonolucent areas, probably secondary to necrosis or hemorrhage, were seen in the tumors of five patients. Serial examinations were performed during the course of chemotherapy and/or radiotherapy in seven patients. These studies were examined retrospectively to determine whether a specific change in the echo characteristics of the tumor occurred during therapy. No such specific change was observed in these patients. Ultrasound was useful in following tumor size and thus, response to therapy, which is important with the advent of newer, more conservative forms of therapy for rhabdomyosarcoma.