Application of laser scanning cytometry for evaluation of DNA ploidy in routine cytologic specimens

The laser scanning cytometer (LSC) is a relatively new instrument that comb ines the features of both flow and static image cytometry. The purpose of t his study was to examine the application of the LSC for evaluation of DNA p loidy in routine cytologic specimens. The material for this study consisted of 60 routine cytologic specimens obtained from 33 males and 27 females ra nging in age from 23-87 yr (mean, 58 yr). The specimens were simultaneously stained with propidium iodide and FITC-cytokeratin. either on Thin-Prep sl ide (35 cases) ol in a concentrated cell suspension (25 cases). In each cas e a minimum of 500 cells was evaluated (range, 527-17,963; mean, 3,889). Al l abnormal cell populations were relocated for the presence of malignant ce lls. The results were defined as diploid and aneuploid/tetraploid. In 10 bl adder washes, the results of LSC were compared to results of flow cytometry . Out of 60 specimens, 7 (11%: 6 bladder washes and I renal wash) were excl uded doe to low cellularity. Of the remaining 53 cases, 11 (20%) were aneup loid/tetraploid and 42 (80%) were diploid. All but one cytologically diagno sed malignancy had abnormal DNA content. Additionally, two bladder washes d iagnosed as suspicious and atypical were aneuploid All abnomal LSC results were confirmed by relocation of the cells. The concordance between pow cyto metry and LSC in the 10 control bladder washes was 100%. In conclusion, LSC proved to be a suitable instrument for the evaluation of DNA ploidy in rou tine cytologic specimens. (C) 2001 Wiley-Liss, Inc.