DNA-PLOIDY BY IMAGE CYTOMETRY IN UROTHELIAL CARCINOMAS - COMPARISON OF TOUCH IMPRINTS AND PARAFFIN-EMBEDDED BIOPSIES FROM 31 PATIENTS

OBJECTIVE: To compare DNA content measured by image cytometry from tou ch imprints and formalin-fixed, paraffin-embedded samples in bladder c arcinomas. STUDY DESIGN: Thirty-one biopsies of urothelial carcinomas were selected for a prospective study. Imprints of fresh specimens wer e performed. Cell suspensions were obtained from dewaxed samples by th e procedure of Hedley. Sections 7 mu m thick were used for carcinoma i n situ and small biopsies. The DNA ploidy index was measured on Feulge n-stained slides using an image cytometer. RESULTS: From imprint analy sis, seven grade 1 carcinomas (n=9) were found to be diploid (78%). Ni ne grade 2 carcinomas (n=12) exhibited aneuploidy (75%), as did all gr ade 3 and in situ carcinomas (n=10). Multiploidy was demonstrated from imprints in four cases instead of the two detected from dewaxed tissu e. In 27 cases (87%), G0/G1 peaks obtained from paraffin blocks showed a shift to the left. In five cases (16%), variations in the DNA index were responsible for discrepancies in the DNA ploidy evaluation betwe en fresh imprints and dewaxed samples of the same tumors. CONCLUSION: Image cytometry on Feulgen-stained imprints of bladder biopsies is a s imple and reliable procedure for assessing DNA ploidy in urothelial ca rcinomas, providing great sensitivity for detecting small aneuploid pe aks and multiploid tumors. DNA image analysis of touch preparations is especially useful for carcinoma in situ and small biopsies unsuitable for Hedley's technique.