PLOIDY RESULTS IN PROSTATIC-CARCINOMA VARY WITH SAMPLING METHOD AND WITH CYTOMETRIC TECHNIQUE

To evaluate the effect of sampling method and cytometric method on DNA ploidy results, a comparison study was performed on 20 whole prostate glands removed at prostatectomy. Fresh sampling was by sampling fine- needle aspiration (FNA). Paraffin sampling was by microdissection and re-embedding of 3 to 13 (average 6) 5-mm foci of microscopically prove n tumor. Analysis was by flow cytometry and by image cytometry (micros copically guided). In tumor negative cases, flow and image cytometry o f the FNA was diploid in each case, and flow cytometry of paraffin-emb edded tissue was diploid in 5/6 cases. In tumor positive cases, non-di ploid tumor was detected by image cytometry of the PNA in 70%, by flow cytometry of the FNA in 29%, and by flow cytometry of paraffin-extrac ted nuclei in 21%. The most effective combination was sampling fine-ne edle aspiration and image analysis.