Clinical characteristics and outcomes of surgically resected solitary pulmonary nodules due to nontuberculous mycobacterial infections

Background: Limited data are available regarding the detailed characteristics and outcomes of surgically resected nontuberculous mycobacterial (NTM) granulomas. Methods: We evaluated the characteristics of 49 NTM granulomas presenting as solitary pulmonary nodules (SPNs) between January 2007 and December 2016. Results: Twenty-five patients (51%) were male and 27 (55%) were never-smokers. Seven (14%) patients had a history of tuberculosis. More than half (51%) of patients were asymptomatic. On chest computed tomography, the median SPN diameter was 18 mm, and approximately half of all SPNs (49%) were located in the upper lobes on chest computed tomography. NTM strain were preoperatively isolated from sputum (46%, 12/26), bronchial wash fluid (54%, 14/26), and needle biopsy specimens (12%, 3/26). Mycobacterium avium (71%, 22/31) was the organism most commonly isolated, followed by Mycobacterium intracellulare (16%, 5/31). Postoperative pneumothorax and atelectasis developed in four (8%) patients and one (2%) patient, respectively. Five patients received postoperative antibiotic therapy. Over a median follow-up period of 18.0 months, one patient with residual lesions after surgery started macrolide-based therapy due to aggravated symptoms. Conclusions: Most NTM granulomas can be treated completely by surgical resection without antibiotic therapy, and microbiological examination of surgical specimens is important for optimal management.