SESSION TITLE: Pulmonary SESSION TYPE: Global Case Reports PRESENTED ON: 10/10/2018 01:00 PM - 02:00 PM INTRODUCTION: Unilateral absence of left pulmonary artery (UAPA)is a rare congenital abnormality with variable presentation. Patients with isolated UAPA can remain symptomatic in to late adulthood.Unilateral absence of pulmonary artery is a rare congenital malformation that may develop in isolation or in association with congenital cardiovascular anomalies. 1,2Associated cardiovascular anomalies may include Tetralogy of Fallot (TOF), atrial septal defect, coarctation of the aorta, a right-sided aortic arch, truncus arteriosus, and pulmonary atresia .In reported cases of isolated UAPA incidence has been reported to range from 1 in 200,000 to 1 in 300,000. 3 Agenesis of the right pulmonary artery has a greater incidence than agenesis of the left .UAPA is believed to result from the involution of the proximal sixth aortic arch, thereby forgoing expected embryological fusion with the pulmonary trunk . Most common symptoms experienced include recurrent pulmonary infections, hemoptysis, chestpain and shortness of breath upon exertion .We present a case of 45 yrs old female referred for evaluation of unexplained exertion breathlessness found to have unilateral absent left pulmonary artery. CASE PRESENTATION: Middle age lady with moderate persistent asthma on optimised inhaler medications, referred for evaluation of unexplained exertion breathlessness.Patient had longstanding history of exercise intolerance relived by rest. X ray chest showed enlarged right pulmonary artery with prominent vascular markings. A Multi detector Computed Tomography (MDCT) pulmonary angiogram showed dilated main pulmonary artery with absent left pulmonary artery. Echocardiogram revealed severe Tricuspid regurgitation with severe pulmonary artery hypertension. Her pulmonary function test showed modern obstructive pattern. she was started on diuretics and vasodilators along with inhaler medications. DISCUSSION: Left-sided agenesis is a rare entity that occurs half as frequently as right-sided agenesis. Approximately 80% of left-sided agenesis is associated with a congenital cardiovascular malformation necessitating medical attention in early life .The other subset of isolated left pulmonary artery agenesis without associated cardiovascular anomaly, presenting later on in life.The treatment for UAPA is patient specific and will vary depending on age of presentation, associated cardiovascular anomalies, and symptomatology. The options in young patients include revascularization of the distal affected pulmonary artery.Lobectomy, or selective embolization of systemic arterial supply, may be considered for patients with hemoptysis . Asymptomatic adult patients with severe pulmonary hypertension may be started on vasodilators.Regular follow-up and observation of pulmonary hemodynamics is recommended CONCLUSIONS: Early diagnosis and treatment of pulmonary hypertension is required is a serious complication. Reference #1: 1. Aypak C, Yikilkan H, Uysal Z, Gorpelioglu S: Unilateral absence of the pulmonary arteryincidentally found in adulthood. Case Rep Med. 2012, 2012:1-3. Accessed: 2/1/2016:http://www.hindawi.com/journals/crim/2012/942074/. 10.1155/2012/942074. Reference #2: Ghanbari H, Feldman D, David S, Saba S: Unilateral absence of a left pulmonary artery:successful therapeutic response to a combination of bosentan and warfarin. CircaCardiovascImaging. 2009, 2:e46-e48. 10.1161/CIRCIMAGING.108.825745 Reference #3: Kruzliak P, Syamasundar RP, Novak M, Pechanova O, Kovacova G: Unilateral absence ofpulmonary artery: pathophysiology, symptoms, diagnosis and current treatment. ArchCardiovasc Dis. 2013, 106:448-454. 10.1016/j.acvd.2013.05.004. DISCLOSURES: No relevant relationships by Nagarajan Appusamy, source=Web Response