Recurrence of Wilms tumor after apparent cure.

The recurrence of Wilms tumor after a 5-year disease-free interval is rare. We present two patients who had recurrent disease after a disease-free interval of greater than 7 years. Three additional patients, registered with the National Wilms Tumor Study who had a recurrence after 5 years, are also described. Of these three patients, two had nephroblastomatosis. Because more patients are achieving long-term survival, careful surveillance after apparent "cure" is recommended, particularly if nephroblastomatosis is identified in the original nephrectomy specimen.