The use of flow cytometry in the diagnosis and biological characterization of the non-Hodgkin's lymphomas.

The detection of aneuploidy and the estimation of the fraction of cells in S in DNA histograms from patients with human non-Hodgkin's lymphoma are reviewed. Karyotype studies and DNA histograms each have advantages and disadvantages in the detection and monitoring of aneuploidy. The choice of fluorescent stain, staining artifacts, and the criteria for the detection of aneuploidy by FCM must be considered carefully. In general, the B-cell lymphomas are more frequently aneuploid by FCM than the T-cell lymphomas. When determining S fractions in the lymphomas, care must be taken not to exclude the aneuploid cases on methodological grounds; these cases generally have the highest S fractions and their exclusion would bias the data. Multiparameter studies have shown that the most aneuploid component of a mixed clinical sample generally has the highest S fraction in the sample, favoring the concept of clonal selection and clonal evolution of tumors.