Role of biochemical analysis and cytopathologic presentation in diagnosis of malignant pleural effusion

Abstract

Pleural effusion is a pathologic collection of fluid in the pleural cavity. A variety of clinical conditions may be the cause of a pleural effusion. The aim of this study was to determine the efficacy of pleural fluid analysis in the diagnosis of malignant lesions of the pleural cavity. This study was designed to determine the role of biochemical analysis and cytopathologic presentation in the diagnosis of malignant pleural fluid. For this cross-sectional study, data were collected from 280 patients who had undergone pleural tap at Rajaee, Kowsar, and Velayat Hospitals. Details of clinical history; physical examination; radiological, clinical, and anatomical pathologic findings; and immunohistochemistry studies were evaluated. The information was classified according to specified criteria. Both descriptive and statistical analysis methods were applied. The overall mean age was 52 ± 6.37 (ranging from 33 to 76) years. Among the 280 patients, 192 samples had exudative effusions. Malignant effusion was found in 90 patients and tuberculosis in 13 cases. The sensitivity, specificity, positive predictive value, negative predictive value, false negative index, false positive index, and accuracy of two different methods including pleural fluid biochemistry analysis (transudate/exudate) and cytopathology in the diagnosis of malignant pleural effusion were 100, 56.5, 63, 100, 0, 43.5, and 75 % and 90, 100, 100, 92, 10, 0, and 95 %, respectively. In a pleural effusion by using biochemical analysis and cytopathology assessment, the differential diagnosis became quickly narrow. The pleural biopsy was in the last step of the algorithm.