Unilateral pulmonary artery agenesis: An unusual cause of unilateral ARDS.

Unilateral pulmonary artery agenesis (UPAA) is a rare malformation that can present as an isolated anomaly or may be associated with certain congenital cardiac anomalies, such as tetralogy of Fallot, atrial septal defect, coarctation of aorta, right aortic arch, truncus arteriosus and pulmonary atresia. Clinical presentation is non-specific which makes the diagnosis elusive; chronic dyspnea, hemoptysis or recurrent infections are the most common manifestations. Patients may remain asymptomatic until adulthood. There is no definitive treatment for patients with UPAA. Acute respiratory distress syndrome (ARDS) is usually a bilateral disease, unilateral ARDS has been described after lung resection or trauma. We present a case of a 39 year-old woman who developed unilateral ARDS and was later diagnosed with isolated UPAA.