Anomalous systemic arterial supply to the lungs: an unusual etiology for cardiomegaly.

Anomalous systemic arterial blood supply to the lungs is a rare anomaly of lung development. It may present with various manifestations that are shared with more commonly encountered congenital and acquired heart diseases. Thus, it may evade early diagnosis or even lead to a wrong diagnosis and treatment. This lesion should be suspected in left ventricular overload conditions in the absence of a clear explanation.