Ganglion Cyst of the Shoulder Associated with a Glenoid Labral Tear and Symptomatic Glenohumeral Instability

Shoulder pain may be caused by a variety of abnormalities including glenohumeral instability, rotator cuff disease, cervical radiculopathy, nerve entrapment syndromes, neoplasm, tendinitis, adhesive capsulitis, trauma, and degenerative disease of any one of the joints about the shoulder.1, 13, 16 Patients experiencing entrapment neuropathy of the suprascapular nerve usually complain of shoulder pain.21 Symptoms involve the infraspinatus muscle if the entrapment takes place at the spinoglenoid notch, or the supraspinatus and infraspinatus muscles if the lesion is at the suprascapular notch. 3,5,22,24,30 Mass lesions such as ganglion cysts are a common cause of suprascapular nerve entrapment. 8,12,17,18,25 Glenoid labral abnormalities, including acute tears and degenerative changes, are associated with glenohumeral instability.4,9 There is evidence that periarticular abnormalities in other areas of the body may lead to the leakage of synovial fluid and the formation of so-called ganglion cystS.7,1l,15,20 We report a case of ganglion cyst of the shoulder associated with a posterior glenoid labral tear and glenohumeral instability.