Mycobacterium Avium Complex Presenting as a Lung Mass, Broncho-pleural Fistula and Empyema in an Immunocompetent Patient-A Case Report and Review of Literature

Mycobacterium avium complex (MAC) is a non-tuberculous mycobacteria (NTM) that causes subacute or chronic nodular bronchiectasis, cavitary or fibro-cavitary pneumonia in patients with chronic structural lung pathology including emphysema, chronic bronchitis, and bronchiectasis. It is also known to cause pulmonary and extrapulmonary infections in patients with impaired cell mediated immunity such as transplant recipients, (Acquired Immune Deficiency Syndrome) AIDS where it can cause disseminated infections. Empyema from MAC has been reported in immunocompromised patients and is a rare phenomenon. Here we report a patient who presented with chronic left pleural effusion and a left lower lobe lung mass that went undiagnosed for 2 years, despite extensive work-up. Later in his course, he presented with a large effusion complicated by a bronchopleural fistula and was diagnosed as MAC empyema. To our knowledge, this is the first case of MAC empyema, that presented as a chronic lung mass, complicated by a bronchopleural fistula. In this article, we present the clinical, laboratory, and radiological features, with emphasis on a combined medical and surgical approach in the management of MAC empyema. We also provide a brief overview of cases of MAC associated pleurisy and empyema that have been reported in literature.