[A case of lung cancer complicated with active non-tuberculous mycobacterium (NTM) infection successfully treated with anti-cancer agents and anti-NTM agents].

A 55-year-old man with pulmonary Mycobacterium avium complex (MAC) disease was referred to our hospital with dyspnea on exertion and general fatigue. Chest computed tomography (CT) revealed a nodular shadow with pleural indentation in the left S(1+2), left pleural effusion, and a thick-walled cavitary lesion due to pulmonary MAC disease in the right S1. A biopsy specimen of the nodule in the left S(1+2) revealed adenocarcinoma, which various examinations confirmed to be stage IV lung adenocarcinoma (T2aN0M1a) complicated with active pulmonary MAC disease. Anti-non-tuberculous mycobacteriosis (NTM) chemotherapy consisting of rifampicin, ethambutol, clarithromycin and streptomycin was administered to treat the pulmonary MAC disease, and the lung cancer was then treated with 4 courses of carboplatin/pemetrexed. This improved the patient's pulmonary MAC disease, and the lung cancer went into partial remission without severe adverse effects. Although a more detailed analysis of the drug interaction is required, we concluded that a combination of anti-NTM and carboplatin/pemetrexed chemotherapy was safe and effective.