TOPIC: Signs and Symptoms of Chest Diseases TYPE: Medical Student/Resident Case Reports INTRODUCTION: Thoracic aortic aneurysm (TAA) is an uncommon clinical condition, commonly associated with atherosclerosis. It is mostly asymptomatic but aneurysm exceeding 6 cm are at risk of yearly rate of rupture or dissection of at least 6.9% and a death rate of 11.8%. We present to you a case of TAA with rupture presenting with cough, hemoptysis and pneumonitis. CASE PRESENTATION: Patient is a 68 years male who presented to the ED with cough, hemoptysis, chest discomfort for 2-3 days. He had intermittent episodes of fever. COVID test was negative 3 days ago. Past medical history was significant for HTN, Asthma, COPD, Diabetes mellitus, tobacco use disorder. Patient was afebrile with BP of 137/73, HR 72, RR 16, O2 saturation of 89% in room air. Physical examination including chest was unremarkable. Initial workup including CBC was remarkable for WBC of 12500, Hgb of 10.5, INR 0.8, PTT 24, Troponin 5 cm, smokers, COPD, advanced age, hypertension. Thoracic endovascular stent graft surgery, under epidural anesthesia, is the preferred surgical treatment especially in old TAA patients as in our case because of low morbidity, mortality and hospital stay. CONCLUSIONS: Rupture of TAAs is still very rare, but should remain on the differential for a patient with cough, hemoptysis with features of pneumonitis as it is associated with very high morbidity and mortality rates. REFERENCE #1: CL F, Esk, MK ari. Thoracic endovascular aneurysm Repair (TEVAR) for Ruptured THORACIC aortic aneurysms. Published May 2, 2017 REFERENCE #2: Inam, H., Zahid, I., Khan, S.D. et al. Hemoptysis secondary to rupture of infected aortic aneurysm– a case report. J Cardiothorac Surg 14, 144 (2019). https://doi.org/10.1186/s13019-019-0959-y REFERENCE #3: Sun D, Mehta S. Hemoptysis caused by erosion of thoracic aortic aneurysm. CMAJ. 2010;182(4):E186. doi:10.1503/cmaj.090447 DISCLOSURES: No relevant relationships by Luna Khanal, source=Web Response No relevant relationships by Adarsha Ojha, source=Web Response