Pure arterial malformation of the middle cerebral artery: case report and literature review

Abstract

Introduction: Pure arterial malformations (PAMs) are rare intracranial vascular anomalies characterized by dilated, tortuous, and overlapping arteries without an associated venous component. Although their etiology remains uncertain, most reported cases suggest a benign natural history. Case report: We describe a 20-year-old woman who presented with severe headaches, photophobia, and scintillating scotomas. Brain imaging performed during childhood had already revealed dilated and redundant arterial segments in the right middle cerebral artery (M1) and posterior cerebral artery (P1/P2), along with a persistent trigeminal artery. Thirteen years later, new imaging - including CT, MRI, and digital subtraction angiography with 3D reconstruction-showed stability of the lesion, absence of aneurysms, arteriovenous shunting, or any ischemic or hemorrhagic changes. The clinical symptoms were attributed to migraine with aura, and conservative management was maintained. Discussion: PAMs predominantly affect young women and are typically detected incidentally. The middle cerebral artery and posterior circulation are among the most frequent sites. Accurate diagnosis relies on high-resolution angiography to distinguish PAMs from other vascular pathologies, such as arteriovenous malformations or dolichoectasia. Despite their uncertain origin-whether congenital or acquired-available evidence indicates a stable, non-progressive course in most cases. Conclusion: This report reinforces the benign nature of PAMs and supports conservative management with periodic imaging follow-up as the preferred approach.