13-cis retinoic acid treatment of a patient with chemotherapy refractory nephroblastomatosis.

A 9-month-old girl presented with massive bilateral diffuse nephroblastomatosis. After response to actinomycin D and vincristine over a period of 1 year, the nephroblastomatosis continuously progressed under this treatment. As retinoic acid signaling is critical for normal renal development and nephroblastomatosis seems histologically as undifferentiated embryonal tissue, we added 13-cis retinoic acid to the chemotherapy regimen. Three months thereafter, kidney volumes declined significantly over a period of 1 year. Interestingly, nephroblastomatosis-associated acquired von Willebrand disease also resolved. Retinoic acid maybe a novel nontoxic treatment option for nephroblastomatosis requiring further systematic evaluation.