abstract:Alveolar capillary dysplasia (ACD, also congenital alveolar dysplasia) is a very rare congenital malformation involving abnormal development of the capillary vascular system around the alveoli of the lungs. It is a rare cause of persistent pulmonary hypertension in infants. It also may be a rare cause of pulmonary hypoplasia. Until mid-2012, the only possible outcome was neonatal death, with one of the longest surviving infants living 2 months.