Aneurysm of the superficial temporal artery presenting as a parotid mass.

True aneurysms of the superficial temporal artery are rare and are associated with atherosclerosis. If the aneurysm occurs in the proximal portion of the superficial temporal artery, it may present as a parotid mass, encompass the facial nerve, and require superficial parotidectomy, as it did in this patient. Preoperative assessment with ultrasonography was the most useful diagnostic test because the aneurysm was thrombosed and was not visible by angiography. Thrombosed superficial temporal artery aneurysm should be in the differential diagnosis of parotid masses.