SESSION TITLE: Imaging SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/09/2018 01:15 pm - 02:15 pm INTRODUCTION: NTM ( nontuberculous mycobacterial disease ) has been well reported in immunocompetent hosts. MAC (Mycobacterium Avium Complex ) is the most widely encountered form of NTM disease. The clinical presentation and radiographic imaging differs based on whether the patient has pre existing lung disease. In immunocompetentpatients without pre exisiting lung disease MAC is typically encountered in non smoking females greater than 50 years of age. Additional patient specific risk factors are poorly understood. The association between chest wall deformities and MAC lung disease has been previously described but not commonly appreciated by clinicians and radiologists. CASE PRESENTATION: 44 y/o f with a history of Vitamin D deficiency, Thallasemia minor and GERD presented for outpatient pulmonary evaluation of abnormal CT imaging associated with a + PPD. The patient is employed in a hospital setting as a nurse and has had multiple prior PPDs which were + with negative CXR imaging. She had received BCG vaccination as a child in Albania and was never previously treated for latent tuberculosis. On a routine physical evaluation for a new position she was required to have a new CXR performed which revealed subtle airspace and reticular densities in the bilateral mid lung fields. She had a subsequent gamma interferon assay (Qunatiferon GOLD) performed which was negative and was referred for CT imaging and additional pulmonary evaluation to rule out tuberculosis. The patient reported intermittent productive cough with discolored sputum for several years. She denied any weight loss, night sweats, hemoptysis or any known TB exposure. CT chest revealed evidence of bronchiectasis in the RML and lingula associated with centrilobular tree in bud opacities. Additionally on CT imaging and physical exam the pt was noted to have a pectusexcavatum deformity of the chest wall. 3 sets of sputum AFB were + MAC. Treatment was started with ethambutol, rifampin, clarithromycin on a 3 time weekly basis with significant improvement in symptoms. DISCUSSION: Pectus Excavatum, also known as sunken or funnel chest, is a congenital chest wall deformity in which several ribs and the sternum grow abnormally, producing a concave, or caved-in, appearance in the anterior chest wall. Chest wall deformities including pectusexcavatum have been associated with MAC lung disease more so than tuberculous lung disease, but the precise mechanism is poorly understood and not commonly appreciated by clinicians and radiologists. CONCLUSIONS: The combination of a pectus deformity with RML and lungula bronchiectasis in an immunocompetenthost should immediately raise the concern of MAC lung disease. Additional research is warranted to better elucidate risk factors for pulmonary NTM disease. Reference #1: 1- Cherra Pumphrey, MD , Abigail Chandler, MD and et al.MAC Infection in a Man With Pectus Excavatum. November 01, 2007. Pediatr Surg Int. 2001;17:344-350. 4. Reference #2: 2- Honda JR, Knight V, Chan ED. Pathogenesis and risk factors for nontuberculous mycobacterial lung disease. Clin Chest Med. 2015;36:1-11. DISCLOSURES: No relevant relationships by Mona Alipour, source=Web Response No relevant relationships by Farhad Arjomand, source=Web Response No relevant relationships by Louis Gerolemou, source=Web Response No relevant relationships by Nabil Mesiha, source=Web Response No relevant relationships by Viswanath Vasudevan, source=Web Response