Bilateral Wilms' tumor: A clinicopathologic review

Bilateral Wilms' tumor occurs at a younger age than unilateral disease. Whi le it generally has a goad prognosis, it presents a therapeutic dilemma to balance curative surgical resection with preservation of renal tissue. A 15 year review of bilateral Wilms' tumors diagnosed at Princess Margaret Hospital was undertaken. Of 46 Wilms' tumor cases, eight were designated bi lateral by diagnostic imaging (median age 1.1 years compared with 3.5 years for unilateral tumors). The surgical management entailed primary nephrecto my with contralateral biopsy in two patients, and bilateral biopsy and dela yed resection in all remaining surviving patients tone patient died of peri operative complications). Seven patients had localized disease (stage I/II) and the six surviving patients received chemotherapy with vincristine and actinomycin; no patient received radiotherapy. All are alive and well (medi an follow-up 5.1 years). The remaining patient presented with pulmonary met astases and died of disease progression. Pathologic review revealed that fo ur patients had truly bilateral disease demonstrable by histology, three ha d unilateral Wilms' tumor with contralateral nephrogenic rests, and in one patient the biopsies of the contralateral kidney showed neither tumor nor n ephrogenic rests. in most cases pathological material was subject to extern al review. Follow-up demonstrates excellent renal function with compensatory hypertrop hy in the remaining renal tissue. Conservative surgery and simple out-patie nt based, low toxicity chemotherapy is curative in most patients.