Diagnostic Role of Endobronchial Washings and Biopsy in Smear Negative Pulmonary Tuberculosis and Its Correlation With High Resolution Computed Tomography Chest Findings

Abstract

Objective: To determine role of endobronchial washings/biopsy in diagnosis of smear negative pulmonary tuberculosis and evaluate their association with computed tomography findings.
 Study Design: Cross-sectional - analytical study.
 Place and Duration of Study: Department of Pulmonology, Pak Emirates Military Hospital, Rawalpindi Pakistan, from Jan to Jun 2020.
 Methodology: Patients having symptoms of pulmonary tuberculosis and abnormal findings on chest imaging with negative sputum smears for acid fast bacilli were selected for endobronchial washings. Bronchoscopy for washings was carried out in these patients and sample was sent for Acid fast bacilli stain, Mycobacterium tuberculosis gene Xpert and acid fast bacilli culture and sensitivity bacterial culture and fungal hyphae. In case of mass lung endobronchial and/or transbronchial lung biopsy was done and sample was sent for histopathology Active pulmonary tuberculosis was labelled as per definition.
 Results: Out of 105, 75 (71.4%) were male and 30 (28.6%) were female. Mean age was 55.69 ± 17.33 years. Total 40 (38.09%) were diagnosed with pulmonary tuberculosis (based on smear, genexpert, culture and histopathology). In these 40 patients, computed tomographic findings showed consolidation in 10 (25%) cases, cavity in 7 (17.5%), bronchiectasis in 3 (7.5%), mass in 1 (2.5%), pleural effusion in 2 (5%), lymphadenopathy in 1 (2.5%) and tree-in-budappearance in 12 (30%) cases.
 Conclusion: High resolution computed tomography and endobronchial washing both combined together increase the diagnostic yield in smear negative cases.