Detection of deletions in the short arm of chromosome 3 in uncultured renal cell carcinomas by interphase cytogenetics

Purpose: Analysis of genetic alterations may facilitate the differential diagnosis of renal cell carcinoma (RCC) subtypes. For genetic classification, deletion of the short arm of chromosome 3 (3p), the hallmark of nonpapillary/clear cell RCC, is a major diagnostic criterion. Because of the limited routine applicability of cytogenetics and molecular genetic techniques we investigated interphase fluorescence in situ hybridization (FISH) for the detection of this aberration in RCC. Materials and Methods: Using seven chromosome 3 specific probes FISH was performed on isolated nuclei from 26 uncultured sporadic RCC. Results: Alterations of chromosome 3 were identified in 19 RCC (73%). Monosomy and/or 3p-deletions were observed in 15 of 19 (79%) non-papillary/clear cell RCC but not in other morphologic subgroups. The median percentage of cells in a specimen containing loss of 3p was 45%. Deletion mapping indicated that large deletions affecting different regions in 3p are predominant. Chromosomal region 3p24 was recurrently involved in all RCC with a deletion in 3p. Conclusion: Interphase FISH for the detection of loss in 3p provides a sensitive and feasible method for the genetic classification of kidney tumors and the delineation of recurrently deleted regions in 3p.