Extensor pollicis longus tendon compression as the etiology of a true aneurysm of the radial artery in the anatomical snuff box

True aneurysms of the radial artery are rare. The natural history of these aneurysms is not well understood. We report the case of a true aneurysm of the radial artery located in the anatomical snuffbox in a 65-year-old man with no antecedent trauma which was treated with resection and cephalic vein interposition graft. We discuss the treatment options as well as review previous literature on radial artery aneurysms and suggest compression by the extensor pollicis longus tendon on the radial artery as a contributing factor to the formation of these aneurysms.