Hemorrhagic synovial cyst: An unexpected cause of acute cervical spinal cord compression. Case report

INTRODUCTION: Cervical synovial cysts are uncommon. They are most often responsible for a chronic clinical picture. Rarely, intracystic hemorrhage occurs, and may acutely present as radicular – or even spinal cord compression syndrome leading to irreversible neurological impairment. CASE: We reported a case of bleeding synovial cyst located in the cervico-thoracic spine causing spastic paraparesis in a 68-year-old male patient. MRI revealed narrowing of perimedullary subarachnoid space by a well circumscribed, extra-axial, homogeneous mass located posterolaterally to the right of the spinal cord at the level C7-T1. The cyst was removed thoroughly by laminectomy. Pathological findings were consistent with the diagnosis of hemorrhagic synovial cyst. The patient had an excellent recovery. DISCUSSION: Synovial cysts of the spine are rare and usually asymptomatic. It is extremely rare for intracystic bleeding to occur and be responsible for an abrupt presentation. Diagnosis of spinal synovial cyst relies on MRI but may not be evident as it depends on consistency and density of the cystic fluid. Surgery remains the best therapeutic alternative, especially in the case of neurological impairment. CONCLUSION: Surgery should be considered for any cervical synovial cyst. This is motivated by the risk, although rare, of bleeding and the resulting irreversible neurological damage that may occur.