Ulnar artery aneurysms after injury mimicking acute infection in the hand.

Two cases of ulnar artery aneurysm, with concomitant ulnar nerve compression in the palm are presented. Both followed acute injury and presented with an increasingly painful, warm swelling within 2 weeks of injury. An initial diagnosis of infection was made by experienced clinicians in each case. Ulnar artery aneurysm may be wrongly diagnosed as acute infection. It is suggested that simple excision of the aneurysm and ligation of the ulnar artery is the treatment of choice. Angiography should be reserved for those cases where there is doubt about the diagnosis or adequacy of the collateral circulation. Ulnar nerve deficit may be a result of direct injury rather than a neuropraxia from compression by the aneurysm.