The value of bronchoscopy in the diagnosis of mycobacterial disease. A five-year experience.

During five years, 6,879 patients underwent bronchoscopic study at the Mayo Clinic. Mycobacterial cultures were obtained from 4,120 (60 percent). Mycobacterial organisms (typical or atypical) other than Mycobacterium gordonae were isolated in 70/4,120 (1.7 percent) patients. During the same period, 209 patients had culture-proved M tuberculosis from various sources. Bronchoscopy was performed on 34/209 (16 percent) patients. Washings or secretions from bronchoscopy grew M tuberculosis in 32/34 (94 percent) cases. Bronchoscopy and bronchoscopic cultures were important in the diagnosis of M tuberculosis in 16/34 (47 percent) patients. Atypical mycobacteria were cultured from various sources in 428 patients during the period of study. In 254 of these, M gordonae was isolated, but it was considered to be nonpathogenic in all. Of the remaining 174 patients with culture-proved atypical mycobacteriosis, 40 (23 percent) underwent bronchoscopic studies. Of these 40 patients, 24 had active disease and 11 had saprophytic colonization; in five, the disease activity was indeterminate. Bronchoscopic cultures of secretions or washings or both were positive for atypical organisms in 38/40 (95 percent) patients.