Pulmonary Cavitary Disease Secondary to Mycobacterium xenopi Complicated by Respiratory Failure

Abstract

Non-tuberculous mycobacteria (NTM) are a significant cause of pulmonary infection worldwide and can be clinically challenging. Mycobacterium xenopi (M. xenopi) has low pathogenicity and usually requires either host immune impairment, as in the case of a human immunodeficiency virus infection, or a structural lung disease to cause a clinical disease. Comorbidities have an essential role in M. xenopi occurrence. Herein, we present a rare case of pulmonary cavitary disease caused by M. xenopi complicated by respiratory failure and superinfection in a patient with a chronic obstructive pulmonary disease. An 81-year-old woman presented to the hospital with the chief concerns of shortness of breath and productive cough lasting a few weeks before presentation. A computed tomography scan of the chest showed a right upper lobe, thick-walled, cavitary lesion measuring 2.1 cm x 4.3 cm x 3.1 cm with associated bronchiectasis and pleural parenchymal scarring. One year ago, the patient underwent bronchoscopy for a right upper lobe cavitary lesion, which revealed M. xenopi on bronchoalveolar lavage culture. During the current admission, she was started on rifampin, isoniazid, ethambutol, and clarithromycin because the M. xenopi was clinically significant and fulfilled the American Thoracic Society diagnostic criteria for NTM lung disease. A diagnosis of NTM pulmonary disease does not necessarily suggest that treatment is required. The distinction between colonization and illness may be difficult upon the isolation of M. xenopi. A patient-centered approach is essential given that M. xenopi is often considered a commensal pathogen. When treatment is required, a multidrug approach with an individualized, optimal duration of therapy should be considered.

Keywords: copd; mycobacterium xenopi; non-tuberculous mycobacteria; pulmonary cavitary disease; respiratory failure.

Figure 1. Initial coronal computed tomography of the chest showing right upper lobe cavitary lesion (circled)

Figure 2. Initial axial computed tomography of chest showing right upper lobe cavitary opacity (circled) with adjacent bronchiectasis (yellow arrows)

Figure 3. Repeat computed tomography of chest showing right upper lobe consolidation with slight interval enlargement of the right upper lobe cavitary lesion (circled)