An Aneurysm Without a Headache: Large-Vessel Giant Cell Arteritis Presenting Solely as Aortic Aneurysm

Abstract Giant cell arteritis (GCA) is a granulomatous vasculitis primarily affecting cranial arteries, but it may also involve large vessels such as the aorta. Aortic aneurysm as the initial and sole manifestation of GCA is rare, particularly in the absence of classical systemic symptoms, making diagnosis challenging. We present a 71-year-old male with no significant past medical history who presented with chest pain and exertional dyspnoea. Imaging revealed a thoracic aortic aneurysm with severe aortic regurgitation. He underwent ascending aorta and total arch replacement with a frozen elephant trunk procedure, as well as aortic root and valve replacement. Histopathological examination of the resected aorta revealed necrotising aortitis with multinucleated giant cells, consistent with GCA. The patient had no cranial or systemic symptoms of vasculitis. Rheumatology evaluation post-operatively excluded other potential causes, including infective and IgG4-related aortitis. Follow-up CT aortogram showed no evidence of active vasculitis. As a result, immunosuppressive therapy was not initiated, and the patient was placed on imaging surveillance. He remains clinically well. This case underscores the importance of considering systemic vasculitides in patients presenting with isolated, significant thoracic aortic aneurysms. Histological evaluation is crucial for diagnosis when clinical signs are absent. While early rheumatologic involvement is ideal, post-operative multidisciplinary collaboration remains valuable. In selected cases with no radiological evidence of active disease, conservative management with close surveillance may be appropriate. Vigilant long-term follow-up is essential to detect recurrence or disease progression.