Background: A 54-year-old man with a 22-year history of rheumatoid arthritis and an 8-year history of chronic obstructive pulmonary disease presented with dyspnea on exertion, nonproductive cough and fatigue of 1 month's duration. His medication at presentation consisted of etanercept, azathioprine, naproxen and inhaled fluticasone and salbutamol.
Investigations: At presentation, the patient underwent physical examination, chest X-ray and high-resolution CT, blood tests, and bronchoalveolar lavage fluid analysis including auramine stains and gene sequence analysis of cultured Mycobacterium szulgai.