Superficial temporal artery aneurysm with segmental arterial mediolysis: a case report

Segmental arterial mediolysis (SAM) is a rare non-arteriosclerotic and non-inflammatory vascular disease. Superficial temporal artery (STA) aneurysms are usually associated with trauma, surgery, and hair transplantation. Spontaneous aneurysms of the STA are uncommon, but an STA aneurysm caused by SAM is rare. We report a 70-year-old woman with a spontaneous aneurysm of the STA. The mass in the left parietal region was pulsatile and gradually enlarged in size without any history of head trauma. The mass was successfully removed by surgery and was proved histopathologically to be a true aneurysm with SAM.