Diagnosis and Treatment of Scalp Arteriovenous Malformations With Intracranial Extension.

Scalp arteriovenous malformations (AVMs) are rare entities that may present as large, tortuous vascular lesions with resultant craniofacial deformity. Radiologic findings include feeding arteries and veins associated with dilated tortuous vessels. Intracranial extension is rare. A 5-year-old African American male presented with an occipital mass presumed to be a dermoid cyst on referral. Further workup revealed the presence of a scalp AVM that demonstrated extension into the left sigmoid sinus. Radiologic and intraoperative images are presented. Literature search revealed only 4 patients with scalp AVM extending intracranially into the sagittal sinus, 2 of which were managed with coagulation and division of the feeding vessels and the other 2 underwent preoperative embolization. Our patient is the 1st to be reported to have sigmoid sinus extension. Scalp AVMs with intracranial extension are rare, and require further preoperative workup. Following ultrasound evaluation, computed tomography angiography, magnetic resonance angiography, magnetic resonance imaging, or cerebral angiography can be considered. Treatment entails resection, but preoperative embolization is increasingly used, mirroring patients without intracranial extension. Further studies are needed to evaluate the efficacy and risk profile of these treatments.