Ulnar nerve compression in the cubital tunnel by an epineural ganglion: a case report.

Epineural ganglia are considered to be a usual cause of peripheral nerve compression. In this report, we present a rare case of ulnar nerve compression by an epineural ganglion in the cubital tunnel. A 28-year-old right-handed female secretary developed progressive pain, numbness, and weakness in her right elbow, forearm, and hand for 6 months. Atrophy of the adductor pollicis and the first dorsal interosseous muscles was apparent. Clinical examination revealed a cystic mass at the posterior side of the elbow. Magnetic resonance imaging identified a ganglion while electrophysiologic studies revealed a severe conduction block of the ulnar nerve at the elbow. During surgery a 2-cm diameter epineural ganglion was identified compressing the ulnar nerve and was excised using microsurgery techniques. Two months postoperatively, the clinical recovery of the patient was very satisfactory, although the postoperative electrophysiologic studies demonstrated a less dramatic improvement.