Correlation of Pleural Fluid Analysis with Thoracoscopy Guided Biopsy in Undiagnosed Exudative Pleural Effusion

Abstract Background: Despite having a high burden of tuberculosis (TB) and thus pleural effusions, there is very little data or studies available based in India on pleural fluid analysis and thoracoscopic-guided biopsy, and their correlation with each other. The aim of this study was to compare and correlate various parameters of pleural fluid analysis with thoracoscopic-guided biopsy especially in undiagnosed pleural effusions in Indian setting. Patients and Methods: This prospective observational study was carried out in a total of 40 patients above 18 years of age after obtaining institutional ethics committee clearance and written informed consent who were admitted in the Department of Pulmonary Medicine, Sarvodaya Hospital and Research Centre, from August 2022 to January 2024 covering a total duration of 18 months. The data were entered into MS excel and analyzed by SPSS statistical software. Descriptive statistics such as frequency, standard deviation, and t- test was used to determine level of statistical significance which was set at 0.05. Results: The mean age of the study participants was found to be 53.23 ± 19.95 years, male-to-female sex ratio was 1.6:1. The most common cause of exudative pleural effusion was tuberculous pleuritis (40%) followed by malignancy (22.5%). Shortness of breath (67.5%) and chest pain (50%) were the predominant clinical symptoms. Malignant pleural effusions showed a polymorphic predominant cytology while lymphocytic predominant cytology was present in chronic inflammatory effusions predominantly tubercular. Parapneumonic effusions exhibited elevated adenosine deaminase (ADA) levels and more neutrophils in pleural fluid, whereas tubercular effusions demonstrated increased ADA levels with abundance of lymphocytes. Metastatic adenocarcinoma was the most common type of malignancy found on histopathology. Necrotizing granulomatous inflammation and granulomas were the predominant findings on histopathological examination and imprint cytology, observed in 40% and 35% of the study participants, respectively. Pleural biopsy has a significantly higher diagnostic yield for TB as well as malignancy ( P < 0.05). Conclusion: Medical thoracoscopy serves as an effective, safe, and well tolerate diagnostic tool for pulmonologists in assessing undiagnosed pleural effusions postthoracentesis.