Abstract
A 42-year-old man noted a left hypothenar mass about one week after hitting the palm of his left hand. Although he did not seek treatment, numbness and cyanosis of the left 2nd, 3rd, 4th, and 5th digits appeared suddenly about one year later. A computed tomography scan revealed an ulnar artery aneurysm with a mural thrombus, with a maximal diameter of 20mm, at the site where the ulnar artery passed near the hamate bone. The aneurysm was excised, and the ulnar artery was reconstructed with direct end-to-end anastomosis. Traumatic ulnar artery aneurysm is commonly seen in workers who use the hypothenar eminence of their hands as a hammer, and is usually accompanied by finger ischemia.
