Paraffin-embedded lymph nodes from patients with Hodgkin's disease wer
e examined for flow cytometric DNA content. In order to increase the s
ensitivity of the assay we tried to enrich for the neoplastic cells by
bivariate analysis using a polyclonal anti-nucleolar antibody (AN-AB)
and the forward scatter (FSC). DNA aneuploidy was found to be present
in 67 of all 137 cases (49%), in 24 cases only demonstrable by dual-p
arameter analysis. The DNA index varied from 0.69 to 1.89 with a total
of 22 hypo-diploid cases. The number of aneuploid nuclei exceeded the
expected frequency of Reed-Sternberg (RS) and Hodgkin (H) cells in mo
st of the analysed specimens. In conclusion, flow cytometry in Hodgkin
's disease appears to give useful information regarding the ploidy sta
tus and evidence has been provided that the malignant cell population
in Hodgkin's disease is not limited to the classical RS/H cells.