Disseminated Mycobacterium avium intracellulare infection in an "immunocompetent" host.

We are reporting the case of a 37-year-old immunocompetent patient who presented with anterior chest wall swelling, jaw swelling and pain, back pain, night sweats, and unintentional weight loss. He underwent mediastinoscopy with lymph node biopsy, which revealed caseating and noncaseating granuloma and special stains positive for acid-fast bacteria. Cultures from two different sites surprisingly grew Mycobacterium avium intercellulare (MAI), and a diagnosis of disseminated MAI was made. He was switched from antituberculous treatment to MAI treatment.