Report of a scalp arteriovenous malformation spontaneously hemorrhaging into a preauricular sinus.

Arteriovenous malformations (AVMs) of the scalp are rare congenital lesions that can be extremely disfiguring and even life-threatening. Another congenital lesion is the preauricular sinus, which forms when the auricular hillocks fail to fuse. We present a case of an AVM of the scalp that ruptured into a preauricular sinus. The occurrence of these two lesions on the same side of a patient is a notable and previously unreported event. The patient was successfully treated with intravascular embolization and surgical ligation.