Arteriovenous Malformations of the Head and Neck.

Extracranial arteriovenous malformations (AVMs) are complex vascular malformations to diagnose and treat. They are comprised of congenitally derived arteriovenous shunts with chronic vascular expansion, collateralization, and infiltration of local tissue. Their cause remains unclear, but new genetic and molecular clues are emerging. They may present at any age following an early quiescent period. Diagnosis is based on vascular staining, soft tissue expansion, progressive growth, warmth, and pulsations. Focal lesions can be cured, whereas diffuse AVMs demonstrate highly recidivistic disease. Multimodal therapy with staged interventions can improve treatment outcomes, increase treatment intervals, and control disease. Vigilant follow-up is critical.