[Giant coronary artery aneurysm in diagonal artery; report of a case].

We report a giant coronary artery aneurysm occurred in the diagonal artery. A 44-year-old woman was referred to our institution for further examination of chest X-ray abnormality. Computed tomography revealed a 6 cm intracardiac mass adjacent to pulmonary artery. Cardiac catheterization revealed a giant coronary artery aneurysm with the large thrombus in the diagonal artery. A giant aneurysm 6 cm in diameter was exposed through a median sternotomy. Under beating heart with cardiopulmonary bypass, the aneurysm was opened and organized thrombus was removed. The influx and efflux of the aneurysm were identified and ligated. Under arrested heart with cardioplegia, the diagonal artery was bypassed with the left internal thoracic artery. Finally the aneurysm was obliterated with the running suture. The patient discharged at the 17th postoperative day without any complications. Histologic evaluation of the resected aneurysm revealed atherosclerotic change, destruction of vascular layers and infiltration of inflammatory cells. These findings suggested previous history of coronary arteritis. The coronary aneurysm in this case might be resulted from Kawasaki disease.