Cervical aortic arch with mediocystic necrosis.

The case of a 21-year-old woman with symptomatic cervical aortic arch is discussed. Rapid enlargement of an aneurysm at the level of the abnormal arch caused symptoms that prompted the patient to undergo angiographic diagnosis and surgical repair. Histologic examination of the aneurysm revealed mediocystic necrosis, which contributed to the malignant course of the congenital disease. Successful repair was accomplished without the use of cardiopulmonary bypass.