Utilizing flexible bronchoscopy for the diagnosis of endobronchial tuberculosis with negative sputum acid-fast bacillus

Abstract

Background: Endobronchial tuberculosis (EBTB) should be viewed as a distinct subset of tuberculosis due to various pitfalls: (a) often diagnosed late, (b) mimicking other conditions, for example, lung carcinoma, and (c) risks of bronchostenosis if treated late. Flexible bronchoscopy (FB) offers a reliable and safe modality to increase the diagnostic yield of EBTB when sputum acid-fast bacillus (AFB) is negative. In this study, we aim to determine the clinical presentation, bronchoscopic characteristics, and safety of FB for the diagnosis of EBTB at our centers. Methods: From September 2018 to December 2019, 25 patients with EBTB from Queen Elizabeth Hospital and Labuan Hospital, Malaysia were enrolled in this study. Histopathology and/or microbiology were diagnostic in all patients. All patients underwent FB only after sputum smears for AFB were negative. Results: The most common presenting complaint was cough (68%), followed by loss of weight (52%), loss of appetite (36%), fever (32%), hemoptysis (28%), and dyspnea (24%). Lung mass/nodule was seen on imaging in 56% of patients, followed by consolidation (36%), cavity (36%), tree-in-bud appearance (32%), and collapse (24%). The most common Chung’s classification of EBTB appearance was edematous-hyperemic (60%); other appearances in order of descending frequencies were: fibro-stenotic (24%), caseating (24%), tumorous (16%), and granular (16%). Bronchial lavage cultures and/or histopathology cultures were positive for tuberculosis in 72% of patients. No procedure-related mortality or major complications were reported. Conclusion: Even in tuberculosis endemic settings, empirical pharmacological treatment of all suspected EBTB cases will inadvertently lead to delay in attaining competing differential diagnoses in some. FB in selected patients is safe and effective as it enhances treatment confidence by providing histological and/or microbiological evidence thereby ruling out other differentials when initial sputum results were inconclusive.