A 37-year-old Japanese man presented with a bulla with niveau-like opacity in the right upper lung on chest radiography. Air-fluid level gradually increased despite broad-spectrum antibiotic therapy. Right upper lobectomy was performed, and epithelioid granuloma with mycobacteria was histopathologically observed. Bacterial culture of the fluid was negative, but mycobacterial culture was positive for Mycobacterium avium; therefore, the patient was diagnosed with pulmonary infected bulla caused by Mycobacterium avium. He was further treated with antimycobacterial agents after resection of the infected bulla. To our knowledge, this is the first report of pulmonary infected bulla caused by only Mycobacterium avium in the English literature.
Keywords: Mycobacterium avium; infectious bulla; lung resection; nontuberculous mycobacteria.