A case of bilateral Wilms' tumour of the kidneys and the retrourethral region.

Bilateral Wilms' tumour of the kidneys and the retrouretheral region in a 52-day-old boy is reported. These tumours are of the same histological appearance, similar to that of a malignant rhabdoid tumour of the kidney. We suggest that these tumours have arisen from the mesonephric duct or the mesonephros and Wilms' tumour may have originated from mesonephros or an even earlier developmental stage.