Severe Ulnar Neyropathy in Guyon’S Canal Caused By a Distal Tendon Sheath Ganglion Cyst

Abstract

We present the case of a 53 years old woman with rapidly worsening ulnar neuropathy so as to accentuate the misleading complexity of the symptoms that can be attributed to the rare location of the ganglion. She first presented with upper limb symptoms due to pressure of the ulnar nerve in guyon’s canal. She complained for severe pain and numbness in the palmar hand distribution of ulnar nerve and clinical examination revealed claw hand and positive Froment sign. A feeling of causalgia was present for many years but the aforementioned symptoms developed suddenly in just a month. The preoperative MRI showed a multilobed ganglion. During the excision operation, we found the ganglion originating from the tendon sheath of flexor digitorum profundus of the little finger. It was compressing both the deep motor branch of the ulnar nerve and the 4th common digital nerve. One year later, the patient shows significant decline of symptoms. The ulnar tunnel neuropathy, although rare, should be diagnosed quickly because it sometimes shows rapid deterioration. To our knowledge, it is a very scarce case because of its difficulty for classification and the ganglion’s distal location and origin.