Alarming Internal Carotid Artery Aneurysm Eroding the Sphenoid Sinus.

In rare instances, extradural internal carotid artery aneurysms can present with massive epistaxis, which is often a fatal event. We present the case of a young female with an aneurysm eroding through the sphenoid sinus and whose timely diagnosis resulted in treatment of the aneurysm with coil embolization and satisfactory outcome.