Background:
Spontaneous superficial temporal artery (STA) pseudoaneurysms are very rare; only four cases, including ours, have been reported to date. Therefore, the cause of them has not been studied.
Case description:
A 57-year-old woman was admitted to our hospital with a pulsatile mass in the left preauricular region. Her medical history included hypertension, dyslipidemia, and angina pectoris. She denied a history of head injury or minor head trauma. Three-dimensional computed tomography angiography showed a well-enhanced saccular aneurysm on the main trunk of the STA. To prevent rupture it was removed surgically. The histological diagnosis was pseudoaneurysm with atherosclerosis. By the 2(nd) postoperative day, she had completely recovered and was discharged home. There has been no relapse.
Conclusions:
As all four documented patients were at high risk for atherosclerosis, we posit that a causal factor was weakening of the arterial wall due to atherosclerosis and chronic pressure on the STA from anatomical structures. Here, we present histological evidence to support this hypothesis.