Arteriovenous malformation of the scalp: case report and review of the literature.

Background: Arteriovenous malformations (AVMs) of the scalp are relatively rare, and their precise natural course remains to be elucidated. We encountered a patient with a scalp AVM that progressively enlarged over the course of 3 years by capturing feeders from intracranial arteries. To our knowledge, ours is the first serial angiographic depiction of the growth of a scalp AVM and the development of a de novo aneurysm in the superior temporal artery (STA) that performed as a feeder.

Case Description: This 21-year-old female consulted us in 1998 complaining of right tinnitus and a pulsating mass in the retroauricular region. The initial angiogram revealed an AVM in the right temporo-parietal subcutaneous space with feeders from the STA, an occipital artery, a posterior auricular artery, and a middle meningeal artery (MMA). Three years later, she complained of enlargement of the lesion, increased tinnitus, and alopecia. Repeat angiographic study revealed the presence of a nidus and the appearance of new feeders from a contralateral MMA and an ipsilateral middle cerebral artery; there was a de novo saccular aneurysm in the right STA. On the day preceding surgery, the left MMA was embolized to control intraoperative bleeding. The AVM was removed totally without any dermal complications.

Conclusion: This case suggests that scalp AVMs can become enlarged by capturing subcutaneous or intracranial feeders, and that the consequent hemodynamic stress may induce de novo aneurysms in scalp AVMs. Capillary endothelial cells were strongly immunostained for vascular endothelial growth factor.