Extrarenal Wilms' tumor.

Extrarenal nephroblastoma (Wilms' tumor) is very rare with to date just 34 cases described. Two such cases out of a total of 61 patients with WT presenting to a single institution over a 10-year period are presented. Both children, a boy aged three years and a girl aged four years, both presented with an abdominal mass which had crossed the midline. Ultrasonography and contrast studies in the two patients revealed retroperitoneal tumors distinct from kidneys, but unilateral hydronephrosis was noted in both patients. Primary surgical excision was performed and both patients grouped as stage III favorable histology. Postoperative treatment included chemotherapy and radiotherapy as per UKCCSG protocols. The patients are clinically well with no evidence of disease 7 years and 20 months respectively from diagnosis. An individualized approach to treatment of extrarenal WT is advocated.