Cervical synovial cysts: case report and review of the literature

The authors describe the case of a 58-year-old man with a 6-month history o f severe myelopathy. CT scan and MRI of the spine revealed a cystic formati on, measuring about 1 cm in diameter, at C7-T1 at a right posterolateral si te at the level of the articular facet. At operation the mass appeared to o riginate from the ligamentum flavum at the level of the articular facet and was in contact with the dura mater. Once the mass had been removed, there was a significant amelioration of the patient's symptoms. As previously sus pected, histological aspect was synovial cyst. Cervical synovial cysts are extremely rare and, as far as we know, only 22 cases have so far been descr ibed in the literature. Diagnostic radiological investigations used were CT scan and MRI. At CT scan the most important diagnostic findings are a post erolateral juxtafacet location of the mass, egg-shell calcifications on the wall of the cyst, and air inside the cyst. At MRI the contents of the cyst are iso/hypointense on T1- and hyperintense on T2-weighted images. There m ay also be a hypointense rim on T2-weighted images, which enhances after i. v. administration of Gadolinium. Surgical treatment consists of removal of the mass. Fixation of the vertebral segments involved is not always necessa ry.