C68-03 Atypical Mycobacterial Avium Complex Infection in Immunocompetent Male

Abstract Purpose Mycobacterium avium complex (MAC) is a ubiquitous acid fast bacillus and the most common cause of nontuberculosis mycobacterial infections in humans. While MAC commonly affects immunocompromised patients, immunocompetent individuals can rarely develop both localized and disseminated infections, often associated with pre-existing lung disease, thoracic and skeletal abnormalities, low CD4 in lymphoreticular malignancies, and elderly women who suppress cough. There are two major phenotypes on CT: cavitary and nodular bronchiectatic, with the latter having more favorable outcomes. Specifically, noncavitary MAC is also associated with use of inhaled corticosteroids, solid tumors, or pneumonia. The purpose of this case report is to highlight the difficulties in diagnosis of non-tuberculosis mycobacterial infection in immunocompetent patients and patient centered management decisions in chronic MAC. Summary of the Case We present an 82 year old male who presented with acute onset hemoptysis. History revealed atypical bronchopneumonia five months prior to presentation with negative AFBs at that time and squamous cell carcinoma of nasopharynx in 14 years prior to presentation. History ruled out immunodeficiency, chemical exposure, any systemic symptoms, or any of the above conditions commonly associated with MAC in immunocompetent hosts. CT angiogram during admission showed persistent multifocal nodular peribronchial consolidative opacities in association with endobronchial impactions. BAL was without any notable lesions or source of bleed. He was found to be AFB positive x 3 with negative TB PCR, eventually diagnosed with chronic MAC. The patient with his infectious disease team decided to proceed with clinical and radiographic surveillance off of antimicrobial therapy for three months. Conclusion This case highlights an atypical presentation of pulmonary MAC in an immunocompetent host, without any known risk factors for cavitary or nodular bronchiectatic MAC. It illustrates that pulmonary MAC is often underrecognized, especially in the setting of inconclusive diagnostic results. However, we believe it is important to identify those with pulmonary MAC as most patients with positive AFB smears will progress, and there are radiographic changes such as nodules and infiltrations that are reversible with early treatment. Unfortunately, it is difficult to initiate treatment in an asymptomatic patient as there are many side effects to MAC treatment including hepatotoxicity, thrombocytopenia, cutaneous reactions, leukocytopenia, and ocular toxicity. Patient centered decision making is essential. This abstract is funded by: None