Precursor lesions of Wilms' tumor in Indian children: a multiinstitutional study.

BACKGROUND

Studies regarding different ethnic populations of children with Wilms' tumor (WT) in the U. S. have shown differences between age and gender incidence and the type of its precursor lesions (nephrogenic rests). To the authors' knowledge there are few reports in the literature regarding nephrogenic rests in a large number of cases from other parts of the world.

METHODS

In this study, histopathology sections from 127 WTs were pooled from the archives of 4 institutions in northern India and studied for the incidence of nephrogenic rests. Their incidence also was cross-correlated with patient age gender, and tumor morphology.

RESULTS

Significantly, the complete absence of perilobar nephrogenic rests was observed in all cases. Intralobar rests were associated with 45.3% of WTs and were observed predominantly with a triphasic histologic pattern and a relatively lower incidence of anaplasia compared with reports in the Western literature (1.5% vs. 4.5%). A lower median age of 2.5 years with a peak in the first 2 years of life was consistent with reported studies in Asian children. The male gender preponderance was in contrast to the equal male to female ratio reported in Western cases.

CONCLUSIONS

The type of nephrogenic rests present in Indian children was noted to be different from that in children reported in the Western literature. Differences also existed with regard to the age and gender incidence of children with WT and its morphologic pattern, possibly due to the different genetic nature of the tumor. However, this theory requires confirmation by large epidemiologic and genetic studies.