Mycobacterium intracellulare pulmonary infection which co-existed and mimicked lung cancer.

We report a case of Mycobacterium intracellulare (M. intracellulare) pulmonary infection with co-existing lung cancer and presenting as a solitary pulmonary nodule requiring differentiation from lung cancer. Computed tomography showed two nodules (20 mm) with spicula formation and pleural indentation on the right lower lobe of the lung (right S6 and S8). Transbronchial biopsies from the right S6 and S8 nodules revealed mycobacteriosis and adenocarcinoma, respectively. Thereafter, a right lower lobectomy was performed. Cases of pulmonary M. intracellulare disease with solitary nodule are rare. Moreover, M. intracellulare pulmonary infection with co-existing lung cancer is extremely rare.