Pleural pustule - A novel thoracoscopic appearance of pleural tuberculosis.

<b>Background:</b> Thoracoscopic pleural biopsy is the gold standard for diagnosing tubercular pleural effusion(TPE). Various thoracoscopic appearances such as sagograin nodules and caseous necrosis have been described in TPE. In this study we evaluate a novel finding on thoracoscopy, the ‘Pleural Pustule’. <b>Methods:</b> This is a retrospective&nbsp;analysis of patients who underwent thoracoscopy. Visual inspection of pleura was performed to identify abnormalities, and biopsies obtained from those areas. Pleural biopsy was sent for histopathology(HPE), AFB smear, culture, and Xpert MTB/Rif assay. Pleural pustule(PP) was defined as a pus filled nodule on pleural. <b>Results:</b> Of the 259 patients included, 92 were diagnosed&nbsp;with TPE. Pleural pustule(s) were identified in 16 patients&nbsp;with&nbsp;TPE. Presence of&nbsp;PP had a sensitivity, specificity, PPV and NPV of 17.4%, 100%, 100% and 68.7%, respectively, for diagnosing TPE. HPE&nbsp;showed necrotizing granulomas in all. In patients with PP, a microbiological diagnosis of tuberculosis was achieved in 93.7% patients [AFB smear, Xpert MTB/Rif assay and MTB culture positive in 31.3%,93.7% and 43.7% repectively]. There is strong association between presence of&nbsp;PP and positive Xpert MTB/Rif assay(p=0.002) and microbiologic confirmation of diagnosis(p=0.017). <b>Conclusion:</b> Presence of&nbsp;PP on thoracoscopy&nbsp;is diagnostic for TPE. When identified, a biopsy from&nbsp;PP should be performed as it will likely yield a positive microbiologic diagnosis.