Right internal carotid pseudoaneurysm mimicking a retropharyngeal abscess in a child.

A 7-year-old girl with tonsillar infection with antibiotics. Two weeks later, there was a right sided neck lump. Computed tomography scans demonstrated a predominantly hypodense right retropharyngeal area with peripheral enhancement and mass effect. There was intense enhancement within the postero-superior aspect of the lesion which was continuous with the right internal carotid artery. Ultrasound demonstrated tapering of the right internal carotid artery. Magnetic resonance imaging and magnetic resonance arteriography showed a right internal carotid artery pseudoaneurysm. Surgical exploration confirmed the finding. This case highlights an unusual presentation of an internal carotid pseudoaneurysm and how imaging provided the diagnosis.