A Fusiform Epineural Ganglion Encompassing the Ulnar Nerve in the Cubital Tunnel

Abstract

Cubital tunnel syndrome, caused by a ganglion, is rare and most ganglion cysts originate from the medial aspect of the ulnohumeral joint. We present an extremely rare case of a fusiform epineural ganglion, encompassing the ulnar nerve in the cubital tunnel. A 48-yearold man complained of a 6-month history of typical cubital tunnel syndrome symptoms. Electrophysiological studies were compatible with the compressive neuropathy of the ulnar nerve. A fusiform epineural ganglion cyst (1.4 cm in diameter and 7.2 cm in length), which encompasses the ulnar nerve in the cubital tunnel, was found with no connection to the elbow joint. The ganglion cyst was excised and the ulnar nerve anterior transmuscular transposition was performed. Six months postoperatively, the patient was free of pain, tingling sensations, and numbness. In addition, his grip and pinch strength improved, the muscle wasting showed recovery, and an electrophysiological study demonstrated some improvement.