Cytogenetic and molecular analysis of cellular atypical mesoblastic nephroma

Cytogenetic and molecular analyses were performed on three cellular (atypical) congenital mesoblastic nephromas (CMNs). Two cases had trisomy II; in one, it was the sole karyotypic abnormality, and the other had additional numerical changes as well as an isochromosome for the long arm of chromosome I. Markers for the 11p13 and 11p15 loci were present in three copies in these two CMNs. In the third CMN, two apparently normal copies of chromosome 11 were present together with additional numerical and structural chromosome changes. Because loss of heterozygosity was observed for both 11p13 and 11p15 markers, we assume that mitotic recombination occurred. Duplication and loss of imprinting of genes at 11p15 has also been observed frequently in Wilms' tumor. We therefore propose that CMN and Wilms' tumor might share common genetic pathways.