Nerve sheath ganglion of the ulnar nerve.

We report a case of a nerve sheath ganglion of the ulnar nerve at the canal of Guyon. This case involved a ganglion which was confined to the epineurium of the ulnar nerve. and it was completely excised without any damage to the nerve fiber. A nerve-sheath ganglion is rare, but it should be considered in the differential diagnosis of any tumor which is causing neural disturbance.