Sequestration of the lung arising from the circumflex coronary artery.

Sequestration is an unusual pulmonary malformation. Systemic blood supply is commonly from the thoracic aorta, but arteries may occasionally arise from other sites including the abdominal aorta or the intercostal vessels. We report a rare form of sequestration with origin from the circumflex coronary artery. Knowledge of uncommon vascular origins, particularly from coronary arteries, is important to avoid injury and possible ischemia, infarction, exsanguination, or death.