Diagnostic accuracy of effusion cytology

The aim of this investigation was to report on the diagnostic accuracy of c onventional effusion cytology Cytological diagnoses of 300 pleural effusion s and 300 ascites were compared with clinical and/or histological follow-up s of the respective patients. Sensitivity of our cytological diagnoses on p leural effusions was 50.0%, specificity 97.0%, positive predictive value 95 .7%, and negative predictive value 86.4%. Sensitivity in ascitic effusions was 62.4%, specificity 98.0%, positive predictive value 100.0%, and negativ e predictive value 88.3%; 5.8% of diagnoses for pleural and 4.4% for perito neal effusions were suspicious or doubtful. The overall false-positive rate was 0.5%, while the false-negative rate was 31.5%. False-negative results were due to sampling errors in 71% of pleural and 73% of peritoneal effusio ns and to screening errors in 29% and 27%, respectively. Our data and those from the literature show that diagnostic accuracy of effusion cytology is still unsatisfactory and should be improved. Therefore, the use of differen t adjuvant methods is recommended. (C) 1999 Wiley-Liss, Inc.