Image analysis in the determination of ploidy and prognosis in renal cell carcinoma

The usefulness of ploidy determination by flow cytometry in renal cell carcinoma is disputed. An alternative technique for DNA quantitation, computerised static image analysis, has several advantages over flow methods. Tissue from 90 cases of primary renal cell carcinoma was analysed by image analysis. Cases were assigned a histological grade and staged and stratified by the TNM system. Fifty-two cases were diploid, 28 were aneuploid and 9 were tetraploid (1 was unanalyzable). Heterogeneity of ploidy was noted in 4 cases. The degree to which nuclear DNA content exceeded that of normal nuclei from the same block was also calculated (5C exceeding rate). Stage and grade provided independent prognostic information. Aneuploidy was associated with higher mortality but neither ploidy nor 5C exceeding rate were prognostic indicators. Image analysis is a useful and accurate method for ploidy determination and provides additional data on DNA quantitation but this information is not predictive of the clinical outcome.