Intraspinal ganglions of cervical facet joints are rare. Those reported have occurred in the lumbar region. We report a case of an intraspinal ganglion of the cervical facet joint causing radiculopathy (C8 root). The patient was a 69-year-old man admitted with a history of severe pain in the right upper extremity. The pain radiated to the right scapula and forearm. At MR imaging, a ganglion of the facet joint was delineated as a smooth extradural well-circumscribed cystic mass arising adjacent to degenerative facet joint (C7/T1). Surgical therapy resulted in satisfactory recovery.
Two types of cysts that are known to originate from the facet joint are the synovial cyst and the ganglion. Synovial cysts have a histologically identifiable synovial lining and contain clear fluid, whereas ganglion contains gelatinous, highly viscous fluid, has a connective tissue capsule, and lack of a specific lining. This case was ganglion because of lack of a specific lining and gelatinous, highly viscous fluid.
