Extrarenal Wilms' tumor: staging, treatment, and prognosis

Abstract

Extrarenal Wilms' tumors are rare and have mainly been the subject of isolated case reports. This retrospective evaluation of 34 patients suggests a clinical course very similar to that of renal Wilms' tumor. While clinical presentation varies according to the extrarenal localization, investigations to determine the size of the primary tumor (T), regional lymph node involvement (N), and the occurrence of distant metastasis (M) are very similar, ie, chest x-ray, abdominal ultrasound (US), and computed axial tomographic (CAT) scan of the abdomen and chest. Stage grouping according to the pathologic TNM classification showed stage I in 30%, stage II in 10%, stage IIIa in 34%, stage IIIb in 23%, and stage IVa in 3%; four patients could not be staged. Evaluation of therapy and survival indicate the need for postoperative chemotherapy (CT) to all patients, while the same data suggest that the drugs used for renal Wilms' tumor are equally effective for extrarenal Wilms' tumor. Radiotherapy (RT) probably should be reserved for those patients with unresectable gross residual disease and for metastatic disease. The radiation dose used in the reviewed cases varied from 2,000 to 5,000 cGy. However, recent experience suggests that high doses are not justified in renal Wilms' tumor. The estimated overall 2-year survival of the 34 patients is 82% (95% confidence interval, 63% to 92%).