The Value of Cytology in the Diagnosis of Pleural Effusions

The aim of this study is to assess the value of cytology in the diagnosis of pleural effusions. It is a retrospective review of the patients with pleural effusions admitted at our clinic in a 8-year period. We evaluated the cytological and diagnostic results of 470 patients. Male to female ratio was 3:1 with a mean age of 38.6 years (range 18-76 years). Samples were processed and evaluated according to the standard methods. Cytology results were reviewed and the patients were stratified according to the their final diagnosis of the 470 effusions, 40 were transudates. Among 430 exudates, 190 (74.8%) were malignant on pleural fluid analysis alone. Adenocarcinoma was the most common malignancy. Tuberculosis was the second most frequent etiology for the exudative effusions. Cells in benign or malignant effusions were easily recognized without further invasive evaluation, contributing to diagnosis and therapeutic decisions. Diagnostic power of cytology was high and showed a good correlation with the eventual pathologic diagnosis, with an overall 70.6% sensitivity. Cytologic examination of the pleural fluid is a simple minimally invasive procedure as an initial step in the diagnostic work-up of patients with pleural effusions. It does not only provide high diagnostic sensitivity but also leads the clinician in the correct algorithm as the most informative and leading test even when not diagnostic on its own.