Mycobacterium xenopi pulmonary infection:: Evaluation with CT

Purpose: Our goal was to describe the CT appearances of Mycobacterium xenopi pulmonary infection. Method: A retrospective study period of 75 months was used. Eight immunocompetent patients fulfilled the American Thoracic Society criteria for M. xenopi infection and had CT scans of the thorax. CT scans were reviewed by two observers, and decisions were reached by consensus. Results: Seven patients demonstrated upper lobe cavitary disease: one mass with cavity, one nodule with cavity, three consolidation with multiple cavities, and two cavities only. One patient demonstrated upper lobe consolidation only. All patients demonstrated adjacent lung architectural distortion indicating fibrosis and centrilobular nodules suggesting endobronchial spread of infection. Seven patients had a clinical history of preexisting chronic obstructive pulmonary disease that was confirmed by CT. Four patients demonstrated adjacent pleural disease. Conclusion: M. xenopi pulmonary infection usually affects patients with preexisting pulmonary emphysema. It predominantly affects the upper lobes, usually with cavitary opacities and evidence of fibrosis and endobronchial spread of infection.