A giant thrombosed aneurysm of the petrous carotid artery presenting with cavernous sinus syndrome: case report.

Aneurysms involving the petrous Carotid artery are rare and a review of the literature demonstrates that the mode of clinical presentation depends on the direction of expansion of the aneurysmal sac. The eighth nerve is the most commonly affected, followed by the fifth nerve, sixth nerve and seventh nerve, respectively. There has not been reported to date a lesion presenting with cavernous sinus syndrome. We present the case of a 46-year-old woman who complained of left facial pain and pan-ophthalmoplegia, and was shown to have a giant thrombosed aneurysm of the petrous carotid artery extending into the cavernous sinus. Because preoperative evaluation of the patient revealed good collateral flow, proximal balloon occlusion of the left internal carotid artery was performed. Neurological symptoms of the patient resolved 2 months after surgery except for the size of the left pupil. We conclude that an aneurysm of the petrous carotid artery should be included in the differential diagnosis of cases presenting with a cavernous sinus syndrome. Early diagnosis followed by definitive treatment is important for the alleviation of clinical symptoms associated with this lesion.