Routine culture for tuberculosis during bronchoscopy for lung cancer is not warranted

The value of routine culture of bronchoscopy samples when tuberculosis is not strongly suspected has not been defined. We report that in a population with a low prevalence of tuberculosis, none of the cultures obtained in 436 consecutive bronchoscopies performed for suspicion of lung cancer detected tuberculosis. However, 17% of these procedures yielded samples with positive acid-fast bacillus stains and/or cultures showing atypical mycobacteria, predominantly Mycobacterium gordonae or M. avium- intracellulare. Further epidemiologic investigation suggested that the isolation of M. gordonae from culture of bronchoscopy samples reflected instrument contamination during automated cleaning. Five patients received antituberculous therapy pending culture results based on positive acid-fast bacillus stains of bronchoscopy samples, and one of these developed clinical hepatitis during this therapy. We conclude that in populations with a low prevalence of tuberculosis, routine culture of samples obtained during bronchoscopy for lung cancer is not warranted and may result in unnecessary therapy and complications.