Thrombosed left circumflex artery aneurysm presenting with myocardial infarction.

Coronary artery aneurysms are life-threatening conditions that are quite uncommon in adults. They are observed in 1.1% to 4.9% of patients undergoing coronary angiography. They are usually located in the right coronary artery, may sometimes be thrombosed or rupture, and occasionally reach an enormous size leading to compressive symptoms. We report a case of thrombosed left circumflex artery aneurysm presenting with myocardial infarction. The thrombosed aneurysm, which could not be clearly demonstrated by coronary angiography, was definitively diagnosed by coronary computed tomography angiography. No operation was planned owing to total thrombosis of the aneurysm.