Twelve metanephric adenomas (MA) were studied for allelic imbalance at chromosomal regions known to be involved in the genetics of papillary renal cell tumors (RCT) and Wilms' tumors as well as for loci on chromosome 2p13-21. DNA was isolated from paraffin slides, and allelic status was established by fluorescently-labeled microsatellite markers. No allelic changes were seen in the Wilms' tumor gene region at chromosome 11p13 and in the papillary RCT gene region at chromosome 17q21.32. We delineated a tumor suppressor gene region of approximately 8-centimorgan genetic distance between loci D2S2153 and D2S380 on chromosome 2p13. Allelic changes at this region occurred in 56% of informative cases. Our results provide molecular evidence that MA is a genetic entity, and it can be differentiated from both Wilms' tumor and papillary renal cell adenoma.