Stage III cystic partially differentiated nephroblastoma recurring after nephrectomy and chemotherapy.

Cystic partially differentiated nephroblastoma (CPDN) has low malignant potential. We report a 1-year-old with stage III CPDN of the right kidney that recurred following radical nephrectomy and chemotherapy. There was evidence of tumor spillage pre-operatively and intra-operatively. During chemotherapy the disease recurred in the omentum and the peritoneum. Pathology of the recurrent resected cysts revealed a more differentiated biphasic tumor without blastemal elements. It appears that spillage of CPDN in our patient led to dissemination of disease. Chemotherapy failed to prevent recurrence but only mature elements were present following this treatment. The intensity of therapy required to treat CPDN remains undefined.