Discussion:
Congenital, isolated agenesis of pulmonary arteries (UAPA) is a developmental malformation that shows a unilateral absence of the pulmonary artery without the presence of a congenital heart disease [1]. This often leads to pulmonary hypoplasia of the ipsilateral lung [1]. UAPA is often classified as congenital or acquired [1]. Congenital is defined as a developmental defect or malformation during embryogenesis [1,2]. Acquired due to chronic subclinical infection, typically secondary to tuberculosis, that involves the hilum of the lung [1]. UAPA has a bimodal distribution in regard to age of presentation [1]. Those who are present in childhood are often symptomatic as a result of congestive heart failure or pulmonary hypertension [1]. Those who present as an adult are often asymptomatic, typically due to collateral vasculature to the affected lung [1,2]. While there are many modalities that can be used for diagnosis, CT or MR pulmonary angiography is considered the gold standard [1].