A Case of Lung Cancer Originating from Cavitary Mycobacterium xenopi Infection.

Coexistence of Mycobacterium xenopi with lung cancer has been reported. However, lung cancer originating within a pre-existing cavity caused by M. xenopi has not. A 55-y-old woman with a history of smoking presented with complaints of chronic dry cough, night sweats, and weight loss for several months. Computed tomography (CT) scanning revealed a 3.5-cm irregular thick-walled cavity in the right lung apex. Cultures obtained from a CT-guided biopsy grew M. xenopi. The patient received standard treatment, and her clinical symptoms improved, and the radiographic lesion stabilized. However, 2 y later, a repeat chest x-ray showed the original right upper lobe cavity with an interval development of a mass adjoining the cavity. A CT-guided needle biopsy of the new mass demonstrated squamous cell carcinoma. Whenever there is a change in the radiological appearance of a cavity, a repeat biopsy should be performed to exclude lung cancer.