Cytogenetic and corresponding flow cytometric DNA analysis of renal cell neoplasms

Results of flow cytometric DNA content and cytogenetic analyses of six neoplasms representing the spectrum of the morphologic subtypes of renal cell neoplasms are compared. Flow cytometric determinations of DNA diploidy and near diploidy in two renal cortical neoplasms correlated with modal chromosome numbers; however, in three of four neoplasms with a highly aneuploid DNA content, the modal chromosome numbers indicated diploidy or near-diploidy. Our data suggest that the short-term culture conditions used in cytogenetic analysis may favor growth of cells with diploid or near-diploid DNA content. This may explain the discrepancy frequently observed between results obtained using flow cytometry and karyotyping after short-term culture. We also observed (1) abnormalities in the short arm of chromosome 3 in all three nonpapillary neoplasms, (both clear and granular cell types); (2) aberrations in chromosomes 3 and 17 in the two papillary tumors; and (3) normal chromosome 3 in the presence of various random karyotypic anomalies including telomeric associations and a pseudo-diploid modal chromosome number in the only oncocytic neoplasm studied.