Diagnosing sputum/smear-negative pulmonary tuberculosis: Does fibre-optic bronchoscopy play a significant role?

Abstract

Background:Diagnosis of sputum/smear-negative pulmonary tuberculosis patients can be both challenging and time consuming with many patients being put on empirical anti-tubercular treatment. Fibreoptic bronchoscopy may provide a confirmative and early diagnosis in such patients.Aims:To assess the role of fibreoptic bronchoscopy in the diagnosis of sputum /smear-negative pulmonary tuberculosis.Materials and Methods:The study was conducted on 75 suspected sputum / smear-negative pulmonary tuberculosis cases attending Pulmonary Medicine Department of Mamata Medical College and Hospital, Khammam, AP. Fibreoptic bronchoscopy was performed; culture of sputum and bronchial washings for Mycobacterium tuberculosis was done by BACTEC method.Results:A final diagnosis of sputum /smear-negative pulmonary tuberculosis was made in 60 patients. Bronchial washings smear for acid-fast bacilli (AFB) was positive in 21 patients while culture of bronchial washings was positive in 39 patients. In 29 patients, smear or culture of bronchial washing alone contributed to the final diagnosis. Total yield of bronchoscopy in diagnosis of sputum smear negative pulmonary tuberculosis was 83.33% (50/60); bronchoscopy was the only diagnostic method in 66% cases (40/60) with bronchial washings being the only diagnostic method in 48.33%. Bronchial washings smear for AFB and histopathological evidence of caseating granuloma made immediate diagnosis possible in 48.33% (29/60) patients.Conclusion:Our study suggests that fibreoptic bronchoscopy can provide excellent material for diagnosis of suspected cases of Pulmonary Tuberculosis in whom smears of expectorated sputum do not reveal mycobacteria.

Value of bronchoscopy in the diagnosis of sputum smear negative pulmonary tuberculosis

“…10,28 In present study, the positive result of smear examination in the bronchial washing was much higher in cases where histopathology of the bioptic material resulted TB granuloma. Anatomy-pathological examination of bioptic material can immediately establish diagnosis of tuberculosis as well as it helps determine the diagnosis of other diseases with different etiologies.…”

“…From the combination of the positive results of bronchial washing smear and histopathology, the diagnosis was set at 48.3% in the Bachh study, while it was 48 and 50% in the studies performed respectively by Wallace et al and Kulpati et al 5,9,10 If granulomatous inflammation is also recognized as sufficient evidence for early tuberculosis diagnosis, the diagnostic achievement in the Bachh study is 61.6% compared to 75% in the study by Danek and Brower. 10,28 In present study, the positive result of smear examination in the bronchial washing was much higher in cases where histopathology of the bioptic material resulted TB granuloma.…”

“…10 Bronchial washings smear for AFB and histopathological evidence of caseating granuloma made immediate diagnosis possible in 48.33% (29/60) patients. Fibro bronchoscopy provides material for early diagnosis e.g.…”

“…In all patients with cavitation lesions, mucosa was ulcerated and swollen. 10 According to Panda et al, bronchoscopic appearance of bronchial mucosa was normal in 44% of cases, 21% had abnormal granular mucosa, 35% had bronchial mucoid secretions, 5% had tumor like growth, 3% had external compression and 3% had bronchial hemorrhage, and in some cases, there have been multiple lesions. 16 According to a study in our country, the occurrences of chronic bronchitis (36.5% -atrophic bronchitis and 6.8% hypertrophic bronchitis) prevail in the non-specific changes, considering, moreover, that most of the patients were smokers 89%).…”

“…Furthermore, the bronchoscopy provides biopsy of bronchial mucous membrane, tracheobronchial and pulmonary ago biopsies, bronchial washing for Mycobacterium tuberculosis, bronchial brushing, and so on. 1,3,[6][7][8][9][10][11][12] Pulmonary TB is nowadays shifted to older ages, which is also affected by pulmonary cancer, making differential diagnosis difficult. In these cases, FBS, with its macroscopic findings and mainly with the different bronchoscopic specimens including biopsy, brushing and washings, helps greatly in determining the exact diagnosis of bronchial TB.…”