An aneurysm without a headache: large-vessel giant cell arteritis presenting solely as aortic aneurysm.

Giant cell arteritis (GCA) is a granulomatous vasculitis that classically affects cranial arteries but 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 cranial or systemic symptoms, posing a significant diagnostic challenge. We report a 71-year-old man with no significant medical history who presented with chest pain and exertional dyspnoea. Imaging demonstrated a large thoracic aortic aneurysm associated with severe aortic regurgitation. He underwent ascending aortic and total arch replacement with a frozen elephant trunk procedure, together with aortic root and valve replacement. Histopathological examination of the resected aorta revealed necrotising granulomatous aortitis with multinucleated giant cells, confirming the diagnosis of GCA. Notably, the patient had no cranial symptoms, constitutional features, or biochemical evidence of active vasculitis. Rheumatological evaluation performed post-operatively excluded alternative causes, including infective and IgG4-related aortitis. Re-review of preoperative imaging and subsequent follow-up CT aortogram showed no radiological evidence of active vasculitis. In view of the absence of clinical and imaging disease activity, immunosuppressive therapy was not initiated, and the patient was managed with close imaging surveillance. He remains clinically well. This case highlights the importance of routine histopathological examination of resected aortic tissue, particularly in elderly patients presenting with large, unexplained aortic aneurysms and without known connective tissue disorders or significant atherosclerotic risk factors. Recognition of large-vessel GCA may occur only post-operatively, and management should be individualised based on disease activity, with multidisciplinary collaboration and vigilant long-term surveillance playing central roles.