[A case of primary Sjögren's syndrome presenting with middle lobe syndrome complicated by nontuberculous mycobacteriosis].

A 52-year-old woman was found to have abnormal shadows in her chest radiograph in a health examination. At the age of 47 middle lobe syndrome had been pointed out and Mycobacterium intracellulare had been cultured from her sputum. Chest computed tomography scans showed a coin lesion and bronchiectasis in the middle lobe. On the other hand she suffered xerostomia and had a high level of serum anti-SS-A antibody. Further examination of her eyes and mouth gave her a diagnosis of primary Sjögren's syndrome (pSS). By video-assisted thoracoscopic surgery we resected the coin lesion which contained an abscess with acid-fast bacilli, identical to Mycobacterium intracellulare. The histopathology showed lymphocytic infiltration, caseous necrosis with Langhans' giant cells, and epithelioid granulomas. We finally made a diagnosis of pSS presenting with middle lobe syndrome (MLS) complicated by nontuberculous mycobacterial disease (NTM). We discuss the mechanism by which pSS could be complicated by NTM and MLS. Clinicians should pay attention to this possible relationship, especially among middle-aged and elderly women.