Giant Cell Arteritis with a Rare Manifestation of Internal Carotid Artery and Middle Cerebral Artery Stenosis and Cerebral Infarct: A Case Study

Giant Cell Arteritis (GCA) is a granulomatous vasculitis of large and medium arteries, most frequently affecting branches of the external carotid artery and rarely presenting with ischemic stroke. To describe a rare case of giant cell arteritis identified incidentally in a carotid endarterectomy specimen performed for symptomatic internal carotid and middle cerebral artery stenosis leading to cerebral infarction. A 58-year-old male presented with sudden loss of consciousness, slurred speech and right hemiparesis. MRI revealed an acute left gangliocapsular infarct and MRA demonstrated absent flow in the left ICA/MCA. Carotid Doppler showed ~50% stenosis due to an eccentric plaque. The patient underwent left carotid endarterectomy and histopathology unexpectedly showed giant cell arteritis superimposed on a hard atherosclerotic plaque. Corticosteroid therapy was initiated after histopathological confirmation. Routine histopathological examination of CEA specimens can reveal rare but clinically important causes of ischemic stroke, such as GCA, thereby altering long-term management. The patient demonstrated neurological improvement following surgical intervention and corticosteroid therapy, highlighting the importance of routine histopathological examination of carotid plaques in atypical cerebrovascular presentations.