A Case Series of Non-Tuberculous Mycobacterial Pulmonary Disease Masquerading as Malignancy From a Community-Based Hospital.

Non-tuberculous mycobacteria (NTM) are ubiquitous organisms in the environment that can potentially cause a range of pulmonary and extrapulmonary infections in humans. Epidemiological risk factors and the host's immune status determine the susceptibility to various clinical syndromes caused by different NTM species. Non-tuberculous mycobacteria pulmonary disease (NTM-PD) is primarily reported in patients with underlying lung disease. These infections often pose a significant disease burden on affected patients as they are often chronic, difficult to treat, and necessitate long-term multi-drug therapy. complex (MAC) is the most common causative pathogen of NTM-PD in the USA, followed by (). Less common species in the USA include (), , and others, largely depending upon the geographic location and exposure to species-specific predisposing risks. In this case series, the authors report on three elderly patients with chronic lung diseases who had pulmonary NTM disease caused by and MAC. The patients were encountered in both inpatient and outpatient settings from a community-based hospital in the midwestern USA. The clinical and radiological features of NTM-PD masqueraded as malignancy and posed a diagnostic dilemma. The epidemiology, clinical and radiological features, diagnosis, and management of NTM-PD are reviewed in this report.