Huge internal carotid artery aneurysm presenting as tonsillar asymmetry.

Aneurysms of the extracranial portion of the carotid artery are extremely rare. Internal carotid artery aneurysm is an uncommon cause of tonsillary asymmetry. Although internal carotid artery aneurysms usually remain asymptomatic, the clinical manifestation requires the tonsillar enlargement. Asymmetry as a sole determining factor for tonsillectomy may lead to unnecessary operations. We report a patient with a giant internal carotid artery aneurysm presenting as tonsillary asymmetry that might be mistaken for a tonsillar neoplasia. When faced with a tonsillar asymmetry, an otolaryngologist must keep aneurysms in mind.