Ploidy determination in prostatic adenocarcinoma using thin histological sections: a more sensitive way of detecting...

The aim of this study was to compare the results of DNA image cytometry using single-cell preparations to measurements on thin histological slides of the same tumor block, in order to find the most sensitive way for detecting aneuploidy.

Twenty-three cases of prostatic adenocarcinoma were investigated by image cytometry to assess the DNA content of tumor cell nuclei. The histograms obtained by section measurements were corrected using the algorithms of Haroske et al. [Zentralbl Pathol 139: 407-417, 1994] and McCready and Papadimitriou [Anal Quant Cytol 5:117-123, 1983]. The basis for recalculation was an exact determination of the thickness of the sections used.

Out of the 23 cases investigated, 10 tumors were diploid in the single-cell preparations, whereas 13 were classified as nondiploid. After tissue section measurements and mathematical correction of the histograms, five originally diploid histograms showed an additional aneuploid stem line. This was also the case in 8 of the 13 originally aneuploid cases.

Tissue section measurements turned out to be more sensitive in detecting aneuploid tumor cell populations compared to measurements of cytospins of disintegrated tissue. As aneuploidy provides important prognostic information, this more sensitive means of ploidy determination could be of use in prostatic adenocarcinoma, and should especially be used in cases showing diploid histograms in single-cell cytometry.