Management of bilateral Wilms tumours.

Wilms tumour is named after Max Wilms. It is an embryonal tumour derived from the metanephros. It is the commonest childhood renal tumour and the third commonest paediatric malignancy. Synchronous bilateral Wilms tumours (BWT) represent 4-7% of all Wilms tumours (WT) and present at a younger age than unilateral Wilms tumours. At least 10% of synchronous BWTs have unfavourable histology, and up to 22% are associated with genitourinary abnormalities, aniridia, WAGR syndrome, Denys-Drash Syndrome, hemihypertrophy, or one of the other overgrowth syndromes. The long-term disease-free survival (DFS) rate for patients with unilateral Wilms' tumours is approaching 90%, and is around 70% for those with metastatic disease. For both synchronous and metachronous Wilms tumours the prognosis is less favourable with reported cure rates approaching 80% in the best centres and lower in resource poor settings. There is potential for a reduced quality of life due to renal insufficiency and the possible need for renal transplantation. The major clinical challenge in BWTs is preservation of functioning renal tissue using nephron sparing surgical techniques, while achieving cure with minimum therapy-related morbidity. Mortality is generally associated with progressive disease of anaplastic tumours. Chemotherapy followed by nephron sparing surgery has been able, in most cases, to eradicate the tumour while preserving renal function. Radiotherapy has largely been avoided because of fears of long term radiation injury to the residual functioning renal mass. Patient selection, appropriate pre- and post-operative chemotherapy and skilled surgical techniques all contribute to excellent outcomes where these are achievable.