Acute compression ulnar neuropathy at Guyon's canal resulting from lipoma.

There is no reported case of acute compression neuropathy of the ulnar nerve at Guyon's canal that has resulted from lipoma. This report describes a 53-year-old carpenter who presented with a 2-day history of ulnar neuropathy. Exploration yielded a lipoma with interstitial hemorrhage that measured 6.5 by 3.7 by 2.0 cm.