Robert L. Lebowitz, M.D. Children' s Hospital, Harvard Medical School Boston, Massachusetts

This 2 1/2-year-old boy presented with vomiting and dehydration with anuria. His BUN was 32 and his creatine 0.9. CT scan showed bilateral mild hydronephrosis (fig 1) and bilateral distal ureteral calculi (fig 2). The canlculi were not seen on plain film but were evident on non-enhanced CT scan. The boy was eating an unusual diet, high in urate.