Abstract Number ‐ 236: Pure Arterial Malformations: A Case Report

Introduction Pure arterial malformations are dilated, overlapping, and tortuous arteries forming a mass of arterial loops without a venous component. These malformations are rare, with limited cases reported in the literature. Affecting any of the intracranial arteries, they are usually found incidentally and often have a benign course. Methods We present a case of a pure arterial malformation in a young female with hyperprolactinemia. Furthermore, we review the literature and provide an updated summary of these malformations. Results A 28‐year‐old female with a history of infantile hemangiomas, polycystic ovary syndrome, and hyperprolactinemia presented with acne, mild hirsutism, and galactorrhea. Her neurological exam was normal. Magnetic Resonance Imaging (MRI) of the brain with and without contrast ruled out a prolactinoma but revealed a 3 cm vascular malformation at the margin of the left cavernous sinus extending posteriorly into the anterior left perimesencephalic cistern. Initial differentials included a pial arteriovenous malformation or less likely a dural arteriovenous fistula. She underwent a diagnostic cerebral angiogram which revealed a pure arterial malformation without arteriovenous shunting. This was composed of dysplasia of the left posterior communicating artery and anterior choroidal arteries. Stenosis of the left internal carotid artery distally with collateral support into the left anterior cerebral artery and middle cerebral artery was also noted. Lesser changes were noted in the right side with reconstitution of the right anterior cerebral artery from collaterals. Genetic testing for vascular malformation syndromes, including genes known to be associated with hereditary hemorrhagic telangiectasia, was negative. Repeat MRI/MRA done 8 months from the initial scan was stable with no abnormal large arterial venous shunting or definite saccular aneurysm formation noted. Conclusions Although rare, pure arterial malformations should be considered in the differential diagnosis for patients presenting with a cranial vascular malformation. Management of these lesions is usually conservative given their lack of arteriovenous shunting and low risk of rupture, with only a few cases undergoing surgery or endovascular treatment.