The accuracy of gross medical thoracoscopy findings in the diagnosis of pleural tuberculosis: A hospital-based study from Qatar

Background: Pleural tuberculosis (TB) diagnosis is a challenging clinical entity. Medical thoracoscopy (MT) is quickly replacing other diagnostic methods as the preferred diagnostic method for exudative pleural effusions. This study aimed to describe the gross MT findings in pleural TB and to evaluate the accuracy of these findings in the diagnosis of pleural TB in terms of sensitivity and specificity. Methods: This is a retrospective descriptive study involving all patients who underwent MT in the pulmonary department of Hamad General Hospital, from January 2014 to December 2019 to determine the etiology of undiagnosed pleural effusions. Results: We studied 400 cases, 353 (88.3%) were male and 47 (11.7%) were female. Their mean age was 37.49±12.46 years. Gross MT findings included free fluid 400 (100%), nodules 307 (76.8%), adhesions 226 (56.5%), pleural thickening 382 (95.5%), and pleural hyperemia 366 (91.5%). Confirmed cases of pleural TB based on histomicrobiologic studies were 320 (80.0%). The specificities of pleural nodules, adhesions, thickening, and hyperemia were 52.50%, 11.25%, 50.00%, and 25.00%, respectively. While the sensitivities for pleural nodules, adhesions, thickening, and hyperemia were 58.75%, 97.19%, 83.44%, and 95.62%, respectively. Conclusion: Gross MT findings without pleural nodules, hyperemia, and thickening can be used to rule out pleural TB, thereby allowing the treating physician to postpone antitubercular therapy until the final diagnosis is confirmed. However, the presence of these gross findings has no significant association with pleural TB. On the other hand, pleural adhesions showed low sensitivity and specificity for pleural TB.