Diagnostic Utility of Sago-Like Nodules on Gross Thoracoscopic Appearance in Tuberculous Pleural Effusion and Their Correlation with Final Histo-Microbiologic Findings

Background: Distinguishing tuberculous pleural effusion (TPE) from other causes of exudative effusion is often challenging. Delay in treatment initiation can occur while awaiting histo-microbiologic confirmation owing to the paucibacillary nature of the disease. Sago-like nodules are the most common visual finding on gross thoracoscopic appearance. The primary objective was to determine the diagnostic utility of the presence of sago-like nodules on gross thoracoscopic appearance in TPE to help justify early initiation of tuberculosis (TB) treatment based on their finding while awaiting final histo-microbiologic confirmation. Secondary objective was to study the correlation between the presence of sago-like nodules and the final histo-microbiologic findings in pleural biopsy specimens. Methods: This was a retrospective-descriptive study of all patients with exudative pleural effusion who underwent diagnostic medical thoracoscopy (MT) at Hamad General Hospital during an eight-year period (from January, 2008 to December, 2015). Results: The presence of sago-like nodules on gross thoracoscopic appearance of the pleural surface had a sensitivity of 58%, a specificity of 89% and a positive predictive value of 97% for TPE with a diagnostic accuracy of 62%. There is significant association between the presence of sago-like nodules and demonstration of granulomatous inflammation in pleural biopsy specimens (P = 0.000). There is no association between sago-like nodules and positive TB smear and culture in biopsy specimens. Conclusion: The presence of sago-like nodules on gross thoracoscopic appearance has a high specificity and positive predictive value for TPE and significantly correlates with the presence of granulomatous inflammation. Patients from TB prevalent areas with exudative pleural effusion and sago-like nodules on gross thoracoscopic appearance may be commenced on TB chemotherapy while awaiting final histologic confirmation.