A rare cause of root-compression: Subaxial cervical synovial cyst in association with congenital fusion

INTRODUCTION: Synovial cyst in the cervical spine is a very rare pathology that develops from the facet joint. When a synovial cyst emerges into the surrounding space, it can compress the nervous tissue and cause neurological symptoms. In the cervical area there is additionally the risk of spinal cord compression comparing to the more common presentation of synovial cysts in the lumbar spine. PRESENTATION OF CASE: Here, a cervical synovial cysts from the left facet joint grew into the spinal canal and compressed the C8 nerve root which led to root compressing symptoms. Interestingly we found this synovial cyst with congenital fusion. We identified only nine similar cases in the literature. The cyst was removed surgically and the patient discharged without complications. DISCUSSION: Numerous theories have been established to explain the pathogenesis of synovial cyst. Biomechanical alterations of the spine play a significant role in the development of synovial cyst. However, the etiology is still unclear. CONCLUSION: Surgical treatment should be considered in cervical synovial cysts with neurologic deficit or with cord compression or when the conservative treatment is ineffective.