Diagnostic DNA-Flow- vs. -Image-Cytometry in Effusion Cytology

AIMS To determine the sensitivity and specificity of flow- and image-cytometry for the detection of DNA-aneuploidy as a marker for malignant cells in effusions. METHODS 200 effusions (80 tumor cell-positive, 74 negative and 46 cytologically equivocal) were stained with DAPI-SR for DNA-flow- and with Feulgen-Pararosaniline for -image-cytometry. They were measured using a PAS-flow-cytometer and an AutoCyte-QUIC-DNA-workstation according to the ESACP consensus reports for DNA-flow- and -image-cytometry, respectively [7,23,29,49]. RESULTS Sensitivity of DNA-aneuploidy for the identification of malignant cells was 32.1% for DNA-flow- and 75.0% for -image-cytometry, specificity of -euploidy in benign cells was 100.0% for both methods. Positive predictive value of DNA-aneuploidy for the identification of malignant cells was 100.0% for both techniques, negative predictive value of DNA-euploidy was 48.6% for DNA-flow- and 72.0% for -image-cytometry. CONCLUSIONS Searching for DNA-aneuploidy as a diagnostic marker for neoplastic cells in serous effusions image-cytometry revealed superior sensitivity as compared with monoparametric flow cytometry.