Bronchial anthracosis: a potent clue for diagnosis of pulmonary tuberculosis.

OBJECTIVES Occupational exposure to carbon, silica, and quartz particles are predisposing factors for bronchial anthracosis. In some cases anthracosis may be associated with mycobacterium tuberculosis. This study aims to investigate the clinical, radiographic, and bacteriologic findings in bronchial anthracosis patients and its association with tuberculosis. METHODS This is a prospective study conducted between 1998 and 2001. A total of 919 patients underwent diagnostic bronchoscopy for pulmonary diseases. Of these, 71 patients showed evidence of bronchial anthracosis, 32 (45.8%) males and 39 (54.2%) females, age range, 30-92 years. The distinctive clinical features, nature of bronchoscopic lesions, and radiologic findings were analyzed prospectively and summarized. Bacteriologic studies and results of laboratory examinations were also assessed. RESULTS Forty-one (57.8%) patients had positive smears or cultures for mycobacterium tuberculosis. Of 71 patients with bronchoscopic evidence of pulmonary diseases, 30 had previous occupational exposure, and 41 stated no previous exposure. Cavitary lesions on chest radiography, positive purified protein derivative tests and high ESR were more prevalent in tuberculous patients than the others. CONCLUSION Bronchial anthracosis was caused by active or previous tuberculous infection. Detailed examinations for the presence of active tuberculosis should be performed in patients with such bronchoscopic findings in order to prevent the spread of tuberculosis and to avoid unnecessary invasive procedures.