Endobronchial tuberculosis: Bronchoscopic features and microbiological correlation

<bold>Background:</bold> Endobronchial Tuberculosis(EBTB) refers to tuberculous infection of the tracheobronchial tree. The documented cases of EBTB are less than the prevalence because bronchoscopy and high resolution computed tomography are usually not performed in all cases of suspected or confirmed pulmonary tuberculosis. Bronchoscopy with biopsy and bronchial lavage offers the diagnostic choice. <bold>Objective:</bold> To compare bronchoscopic appearances of EBTB subtype with microbiological positivity in endobronchial biopsy and to rule out multidrug resistance tuberculosis. <bold>Methods:</bold> Case records of 15 cases of biopsy proven EBTB were retrospectively reviewed from 2022 to 2023. Diagnosis of EBTB was established histopathologically. <bold>Results:</bold> The commonest subtype was edematous hyperemic(33.3%) followed by actively caseating(26.7%), granular(20%), tumorous(13.3%) and ulcerative(6.7%). 46.7% of endobronchial biopsies were smear-positive for Acid Fast Bacilli (AFB). CBNAAT positivity for Mycobacterium tuberculosis (MTB) in endobronchial biopsy was 26.6%, 13.3%,13.3%, 6.6%, and 0% for the actively caseating, edematous hyperemic, tumorous, granular, and ulcerative subtypes, respectively. MDR TB was seen in the actively caseating subtype (13.3%). CBNAAT positivity in lavage fluid was 40%. <bold>Conclusion:</bold> Edematous hyperemic was the most common EBTB subtype. The actively caseating subtype had the highest CBNAAT positivity for Mycobacterium tuberculosis including MDR. Bronchoscopy should be performed in all patients suspected to have EBTB for histopathological diagnosis and microbiological studies to rule out MDR TB.