Observing the growth of Wilms' tumor.

Four children ranging in age from 2 1/2 months to 4 years had excretory urography initially for reasons other than evaluation of an abdominal mass. Three patients had repeat urography only after masses became apparent at intervals of 8.5 months, 9 months and 15 months after the initial urogram. The fourth patient was followed with interval excretory urography for urinary tract infection and a large renal mass was seen 13 months after the initial urogram. The results suggest that the present data on estimated rates of growth do not support the established theory of the rate of growth for Wilms' tumor.