A Rare Cause of Compression of the Suprascapular Nerve: The Paraglenoid Cyst

INTRODUCTION: The ductal syndromes of the shoulder combine all the compressive processes of the suprascapular nerve at the level of its passage in the spinoglenoid notch and this for several causes. The most common is a lesion of the labrum resulting in the formation of a cyst. These cysts are rare and often underestimated. Provoking a compression of the suprascapular nerve, they are likely to cause an atrophy of the external rotator muscles of the cuff. CASE REPORT: We present a rare case of a paraglenoid cyst resulting in a ductal syndrome by suprascapular nerve compression. A 56-year-old man consulted our department for chronic pain of the left shoulder with a decrease in muscle strength. On clinical examination, the patient had a deficit of external rotation with a clear amyotrophy of the infraspinatus fossa. We opted for arthroscopic surgical resection. At the last follow-up, the patient did not show any more pain, with a total recovery of muscle strength. CONCLUSION: The clinical signs of compressive processes of the suprascapular nerve are quite misleading, so establishing a correct diagnosis and surgical management is vital before irreversible muscularatrophy takes place.