The role of DNA flow and image cytometry in the evaluation of body cavity fluids

In addition to conventional cytomorphologic study, 50 body cavity fluid specimens (benign and malignant) were analyzed by both flow cytometry (FCM) and image cytometry (ICM) in order to evaluate the potential application of these techniques in the diagnosis of malignancy. While 88% of the fluids were similarly classified by FCM and ICM as being either diploid (66%) or nondiploid (22%), with similar DNA index values, nondiploid peaks were identified by ICM alone in 12% of the fluids. Aneuploid populations were present in 92% of the cytologically positive fluids and in 15% of the cytologically negative fluids. All of the latter fluids came from patients who clinically had tumors involving the respective body cavities. These results show that (1) both FCM and ICM are useful adjuvant techniques in the evaluation of body cavity fluid specimens and (2) ICM is superior to FCM in the identification of small aneuploid subpopulations. The identification of aneuploid populations by either method is highly suggestive of malignancy.