DNA ploidy analysis of urinary tract epithelial tumors by laser scanning cytometry

OBJECTIVE: To evaluate a rapid and simple method for DNA content analysis o f urinary tract epithelial tumors with laser scanning cytometry (LSC). STUDY DESIGN: The subjects were 25 patients (37 specimens) who underwent su rgery for urinary tract epithelial tumors. Tissue specimens of such tumors were frozen immediately after tumor resection and stored at -80 degrees C u ntil used. Touch preparations were made and fixed in ethanol at room temper ature. The cell nucleus was stained with propidium iodide solution containi ng RNase, and DNA ploidy was analyzed by LSC. Nuclear debris and overlappin g nuclei were gated out by special statistical filters. In LSC, a normal di ploid reference peak was determined by observing lymphocytes morphologicall y the microscope. RESULTS: DNA ploidy could be evaluated in all tumor tissues. The time it to ok from preparing the tumor specimen to the last measurement Tuns about 40 minutes at the shortest, and measurement of all the specimens was was 2.8-7 .8% (mean, 4.4%). All eight specimens (100%) at grade 1 (G1) were DNA diplo id, but 20% and aneuploid. In total, 15 of the 37 specimens were DNA aneupl oid. All 17 pTa-pT1 specimens (100%) were DNA diploid, but 100% and 50% of the T2 and T3 tumors, respectively, were DNA aneuploid. CONCLUSION One call now supplement a morphologic diagnosis with useful info rmation using LSC of touch preparations of tumors obtained nf surgery or of imprints of archived,frozen specimens. LSC provides excellent DNA histogra ms for surgical specimens and has great potential for clinical application in pathology.