Wilms tumor with extension to the right atrium.

A seven-year-old boy had cardiac symptoms for five months before the diagnosis of Wilms tumor was made. The tumor extended into the inferior vena cava through the renal vein and protruded into the right atrium. All demonstrable tumor masses could be removed at a one-step surgical procedure without using cardiopulmonary bypass. Intensive postoperative chemotherapy has been given, and 15 months after surgery he was without signs of relapse.