[Pulmonary non-tuberculous mycobacteriosis (Mycobacterium intracellulare) with cavities developing in a non-small cell lung cancer patient during chemotherapy].

A 70-year-old man was admitted to our hospital for examination of an abnormal shadow found on a chest radiograph. Chest CT showed a nodular shadow in the left upper lobe S1+2. We diagnosed non-small cell lung cancer (squamous cell carcinoma) clinical stage T4N2M1. Chemotherapy consisting of carboplatin and weekly paclitaxel was begun. After the second course of chemotherapy, another nodular shadow with small cavities in the left lower lobe S6 was seen, and which then increased in size. Bronchial lavage revealed a diagnosis of non-tubercular mycobacteriosis (Mycobacterium intracellulare). Anti-NTM chemotherapy consisting of rifampicin, ethambutol and clarithromycin was started in addition to anticancer chemotherapy, without severe side effects. Although there are some reports of the co-occurrence of lung cancer and non-tuberculous mycobacteriosis, this apparently rare case involved the appearance of a solitary nodule with a cavity caused by pulmonary non-tuberculous mycobacteriosis during anticancer chemotherapy.