The value of fiberoptic bronchoscopy in diagnosis of smear negative pulmonary tuberculosis

Although mycobacterial culture positivity is the gold standard for the diagnosis, the initial approach to the diagnosis of pulmonary tuberculosis (PTbc) is the detection of acid-fast bacilli (AFB) in respiratory specimens as recommended by the World Health Organization. But the physicians have to make a decision for the patients whose sputum smears are negative or who can not produce sputum. Waiting for culture results with radiological follow up or empirical antituberculous therapy are the standard options. In our study we aimed to assess the diagnostic yield of fiberoptic bronchoscopy in patients, suspected to have tuberculosis, whose sputum smears were negative or who could not produce sputum. Fifty six patients who suspected to have PTbc with sputum smear negative were enrolled in the study (fiberoptic bronchoscopy and selective bronchial washings were done to all patients. Bronchial washings were obtained from the affected parts). Mucosal biopsies were done in patients in where endobronchial abnormalities were noted. Transbronchial biopsies were done in selected patients from the radiological localizations. Ziehl-Nielsen staining and culture in L?wenstein-Jensen medium were the microbiological studies. Typical granulomas were expected to detect on histopathologic examination. Bronchoscopic lavage smears were positive for Mycobacterium tuberculosis in 13 (23%) patients. Twenty eight (50%) patients had positive culture. Histopathological results confirmed tuberculosis in eight of 20 patients who had undergone mucosal biopsies, four of seven of transbronchial biopsies, two of three of needle aspiration biopsies. By bronchoscopic procedures early diagnosis was performed in 27 (48.21%) patients. We concluded that fiberoptic bronchoscopy has an important role in the diagnosis of patients suspected to have tuberculosis, whose sputum smears were negative or who could not produce sputum. It is useful and necessary in selected cases.