RESUMO
BACKGROUND: Fetal rhabdomyomatous nephroblastoma (FRN) is a rare variant of Wilms tumor. MATERIALS AND RESULTS: One hundred and thirty two children with kidney tumors were seen at our hospital from 1985 to 1993. Among them were 6 (4.5%) who had FRNs. Five were boys aged 8 months to 3 years; the girl was 17 months old. Three of the four with unilateral disease had tumors so large that they were considered unresectable at diagnosis. Five received pre-operative chemotherapy and three also received pre-operative radiation therapy. None of the tumors responded. Both patients with bilateral tumors died of progressive disease. Three of the four patients with unilateral disease followed for at least one year are alive for 1 to 10 years after diagnosis. CONCLUSIONS: FRN should be in the differential diagnosis of huge kidney tumors in children, and preoperative therapies escalated with caution since FRN is not responsive to treatment used for classic Wilms tumor.
