Abstract
In the diagnosis of primary central nervous system (CNS) vasculitis, it is crucial to rule out clinical, angiographic, and pathological mimics. We report a case of arteriovenous malformation (AVM) mimicking primary CNS vasculitis. A young male presented with intracerebral haemorrhage and no other clinical, laboratory, or angiographic features suggesting vasculitis. Cerebral biopsy showed perivascular inflammation and slight infiltration of the muscular layer of cerebral vessels by chronic inflammatory cells close to the haemorrhagic areas. These findings led to a diagnosis of CNS vasculitis. The patient was initially treated with corticosteroids, but 10 months after the discovery and surgical repair of the AVM, the patient is not receiving any immunosuppressant and has not developed any features of cerebral or systemic vasculitis.