Ulnar Neuropathy due to Intraneural Ganglion Cyst of the Ulnar Nerve at the Elbow

Abstract

Intraneural ganglion cysts are rare mucinous cyst originating within the epineurium of peripheral nerves. They occur most commonly in the peroneal nerve. However, they have also been described in many nerves in the vicinity of synovial joints. Intraneural ganglion cysts in the upper extremity are rare. Those at the elbow joint comprise only 9% of intraneural ganglion ever reported. A 66-year-old and right-handed male patient presented with a sudden onset of right-hand weakness. He initially noticed paresthesia with decreased sensation in the lateral two digits and radial palm in his right hand. Physical examination showed thenar muscle atrophy and muscle weakness of the abductor pollicis brevis in the right hand. Preoperative diagnosis of intraneural ganglion cyst was made on the basis of characteristic magnetic resonance imaging (MRI) findings. On exploration, the ulnar nerve was identified proximal to the elbow joint. Its articular branch was addressed and divided from the elbow joint. To the best of our knowledge, addressing the articular branch connecting the glenohumeral joint for the treatment of intraneural ganglion at the elbow has only been reported twice. We experienced a rare occurrence of intraneural ganglion cyst at the elbow manifesting an ulnar neuropathy. Here, we report intraoperative findings for the articular branch-connected to intraneural ganglion of the ulnar nerve at the elbow. Early diagnosis of intraneural ganglion with precise identification of the pathology and addressing the articular branch with atraumatic dissection of ganglion cyst are essential to achieve successful treatment for this rare lesion.

Keywords

• cyst
• intraneural ganglion cyst
• ganglion
• ulnar nerve
• ulnar neuropathy