DNA CONTENT IN NON-HODGKINS-LYMPHOMA - COMPARISON BETWEEN FLOW-CYTOMETRY AND CYTOGENETICS IN FRESH AND PARAFFIN-EMBEDDED TISSUE

DNA content of 36-non-Hodgkin's lymphomas was analyzed by flow cytomet ry (FCM) and cytogenetics (CG), 21 in fresh and 15 in paraffin-embedde d tissue. The results of both techniques were coincident in 60% of the fresh tissue samples and in 45% of the paraffin-embedded ones, the re ason for this difference could be the poor resolution of DNA histogram s from paraffin-embedded tissue. All samples judged as aneuploid by FC M were aneuploid also by CG. Some samples,vith a hyperdiploid populati on by CG gave a diploid population by FCM with a 'false' high DNA-synt hesis (S) fraction. From a technical point of view, CG and FCM have to be performed on the same fresh tissue.