Renal cell carcinoma is unusual in children. We report a case of anapl
astic renal cell carcinoma arising in a 7-year-old girl following trea
tment for Stage III neuroblastoma. The renal cell carcinoma has unusua
l histologic and ultrastructural features, which are discussed. The ca
se is further unusual in that few children with advanced stage neurobl
astoma survive long enough to develop second malignant neoplasms.