Diagnostic Value of Thoracoscopic Biopsy in Patients with Undiagnosed Exudative Pleural Effusion

Background: Pleural effusion of unclear cause remains a diagnostic challenge. Even after thorough evaluation, etiology may be unidentified. Cytology detects metastatic pleural disease in only 60–80% of cases and mesothelioma in 20%, making thoracoscopy often necessary for diagnosis and therapy.Aim: To assess the diagnostic value of thoracoscopic biopsy in undiagnosed exudative pleural effusion.Patients and Methods: In this single-center, prospective trial (July 2022–December 2023), 100 adults (>18 years) with undiagnosed exudative pleural effusion at Suez Canal University Teaching Hospital underwent medical thoracoscopy. Exclusion criteria included trapped lung, unstable cardiovascular disease, severe COPD, bleeding diathesis, transudative effusions, and advanced uncontrolled illnesses. Data included demographics, history, examination, imaging, pleural fluid analysis, and biopsy findings.Results: Mean age was 58.19 ± 10.99 years; 52% were male. History of cancer was present in 38%, tuberculosis in 6%, and smoking in 21%. Thoracoscopic pleural biopsy achieved 95.0% diagnostic accuracy, with 93.8% sensitivity, 100.0% specificity, and 100.0% positive predictive value.Conclusion: Thoracoscopy is a safe, minimally invasive procedure with high diagnostic yield for undiagnosed exudative pleural effusion and should be performed promptly in suitable patients.Keywords: Thoracoscopic Biopsy, Undiagnosed Exudative Pleural Effusion