Scalp Arteriovenous Malformation (Cirsoid Aneurysm) in Adolescence: Report of 2 Cases and Review of the Literature

Background: Scalp arteriovenous malformations, also known as cirsoid aneurysms, are rare lesions that are congenital, traumatic, or postinfectious in nature. These lesions may be found incidentally or owing to signs and symptoms that they produce, such as an enlarging pulsatile mass, headache, tinnitus, or bleeding. These lesions often constitute high-flow arterial blood from the superficial temporal or occipital arteries with venous outflow into extracranial venous structures. Methods: We describe diagnosis and management of 2 cases of congenital scalp arteriovenous malformations in adolescent patients. One case had more typical vascular supply and outflow, whereas the other case demonstrated more uncommon arterial blood supply from extracranial ophthalmic arteries as well as a component of transosseous venous drainage into the intracranial superior sagittal sinus via emissary veins. Results: Treatment of these lesions usually consists of endovascular embolization followed by surgical resection. Conclusions: Both scalp AVMs described were successfully excised after transvenous embolization. Consideration of risks of intracranial venous drainage must be taken into account when evaluating AVM anatomy.