Huang HL, Lee MR, Liu CJ, et al. - Researchers assessed patients with negative nontuberculous mycobacterium (NTM) culture from ≥ 2 expectorated sputum samples within the 3 months before bronchoscopy diagnosis of NTM-pulmonary disease (PD) to determine the clinical features, outcome, and predictors of radiographic progression in this special population. The occurrence of radiographic progression within 2 years was reported in 17 of 66 patients with bronchoscopy-diagnosed NTM-PD. The occurrence of radiographic progression was noted in 17 of the 60 patients not initially treated. Male sex, BMI < 18.5 kg/m², use of inhaled corticosteroids, and acid-fast smear grade ≥ 2 of index bronchoscopic samples were all identified as independent predictors of radiographic progression. Findings revealed radiographic progression within 2 years in one fourth of overall patients with bronchoscopy-diagnosed NTM-PD. The cases with the aforementioned predictors exhibited even higher risk, immediate treatment or close monitoring was advised. For others, the optimal option may be conservative treatment by regular microbiological monitoring for sputum samples and image follow-up.