COMPARATIVE-ASSESSMENT OF DNA ANALYSIS IN EFFUSIONS BY IMAGE-ANALYSISAND FLOW-CYTOMETRY

Cytologic evaluation of body cavity fluids is useful to detect maligna ncy within the pleural and peritoneal spaces. A definitive diagnosis c annot always be made on cytologic evaluation alone. As malignant proce sses may show abnormal DNA content, DNA analysis of effusions may be u seful Therefore, we determined the DNA content of 37 effusions by flow cytometry (FC) and image analysis (IA) using the CAS 200. Of the 37 f luids evaluated, 18 were cytologically malignant, 15 benign, and four atypical. Overall, all, 22 fluids (60%) showed concordance between FC and IA. None of the benign fluids were aneuploid. All showed diploid h istograms or diploidy with increased proliferating cells. Three of fou r atypical fluids had increased proliferating cells by either FC or IA , whereas one was diploid by both methods. Aneuploidy was detected in 13 malignant fluids: five were aneuploid by both methods and eight by only one method. IA identified aneuploidy in five of those eight cases , while three were identified by FC. Three of the cytologically malign ant fluids were diploid by both methods, and two showed increased prol iferating cells by IA and diploidy by FC. The specificity of both meth ods was 100%. However, the sensitivity of identifying a malignant flui d by aneuploidy is low, 44% for FC and 55% for IA. IA appears to ident ify small aneuploid populations more frequently than FC. The detection of aneuploidy in effusions is highly suggestive of malignancy, and th e combination of both techniques gives the highest detection rate (72% ). However, neither are as sensitive as traditional cytologic evaluati on with the occasional use of additional histochemical stains. Diagn C ytopathol 1994; 10:62-67. (C) 1994 Wiley-Liss, Inc.