Panel A

A 59-year-old female with hypertension presented with an 8-month history of headache and an asymptomatic pulsatile mass on her left lateral forehead (Panel A). There was no prior history of trauma or sepsis. Com-puted tomographic angiography obtained by the family physician confirmed the presence of an aneurysm of the superficial temporal artery (STA) (Panel B, arrow). Labo-ratory studies (leukocyte count, VDRL, C-reactive protein, immunoelectrophoresis, anti-nuclear and anti-smooth muscle antibodies) were normal. Subsequent imaging did not reveal aneurysms in other regions. Ultrasonogra-phy showed a 1.5 × 1 cm saccular aneurysm of the STA containing mural thrombus. The aneurysm was resected under local anaesthesia (operative findings, Panel C)