Huge saccular aneurysm in a coronary-pulmonary fistula fed by the left and right coronary arteries.

A 62-year-old woman was referred because of an abnormal mediastinal shadow that had first been noted 4 years ago on the left cardiac border on plain chest roentgenogram and which had gradually increased in size since. A huge saccular aneurysm in coronary-pulmonary fistula into which both the left and right coronary arteries drained was revealed by computed tomography and coronary angiography. The patient underwent aneurysmal resection and ligation of the fistulas. Histological study of the aneurysmal wall did not reveal atherosclerotic change but instead cystic medial necrosis, although there was no other clinical manifestation associated with this.