Abnormal vessel of the ear associated with congenital arteriovenous malformation in the postauricular region.

Variations in the branching pattern of the common, external, and internal carotid arteries can present as arteriovenous malformations, and their basis can be explained embryologically. Our case was a rare variation presenting as a congenital, very gradually increasing bluish painless swelling at the region of the left lobule of the ear arising from an abnormal vessel (from the postauricular artery) which was explored under general anesthesia through a postauricular curved incision. The abnormal vessel and other feeding vessels were ligated and a sclerosing agent injected. Anomalies of pharyngeal arch arteries like our case can be found resulting from the persistence of channels that normally disappear, and prior knowledge of these anomalies is essential before surgeries like mastoidectomy to prevent alarming hemorrhage.