Unilateral absence of a pulmonary artery.

Congenital absence of a main pulmonary artery is a rare anomaly. Most patients without associated congenital cardiac abnormalities are asymptomatic, and the diagnosis is first suggested by the appearance of the involved lung on a routine chest roentgenogram. The ipsilateral lung will be smaller than normal, and the contralateral lung will be overinflated and may herniate across the midline. We describe eight children with unilateral pulmonary arterial atresia (seven on the right side, four of whom were without associated cardiac anomalies).