Non-tuberculous mycobacterial infection of the parotid gland in an immunocompetent elderly patient.

We experienced an extremely rare case in which combined antibacterial therapy for a non-tuberculous mycobacteria (NTM) infection of the parotid gland achieved a favourable outcome in an elderly immunocompetent patient. Although a 79-year-old man, who presented with swelling and fistula formation in the left parotid gland region, initially received combined antituberculous therapy due to a positive result of acid-fast staining, the lesion did not respond to these agents. Thereafter, since the culture examination did not detect Mycobacterium tuberculosis or NTM, we excluded tuberculosis and considered the possibility of an NTM infection caused by a rare mycobacterial species. Therefore, we switched to the clarithromycin-based antibacterial treatment for eight consecutive months without a surgical intervention, resulting in the complete disappearance of the lesion and no evidence of recurrence detected for 4 years. This conservative chemotherapy might be a feasible alternative to a surgical intervention for treatment against NTM infections of the parotid gland.