Clinical features and surgical management of rare cases of thoracic intraspinal cysts: Report of 3 cases

Intraspinal cysts can cause myelopathy or radiculopathy by compressing the spinal cord or nerve root. These cysts occur commonly in the lumbar or cervical spine and rarely at the thoracic level, because spinal instability is considered to be the cause of intraspinal cysts. Intraspinal cysts include synovial cysts, ganglion cysts, ligamentum flavum cysts, neurenteric cysts, arachnoid cyst. Among them, the most common types are synovial and ganglion cysts, which arise from facet joints. Synovial cysts are pathologically distinguished from ganglion cysts by having a thick wall lined by synovial cells. Diagnosis of ganglion cysts also can be made on the basis of the characteristic jelly-like fluid content. The ligamentum flavum also can form cysts when hemorrhage occurs inside, and these are called ligamentum flavum cysts. In this report, we present 3 cases of rare thoracic intraspinal cysts that were successfully treated by surgical resection; discuss the features of these cysts on preoperative images, the intraoperativefindings, treatment options, and pathological findings; and review the relevant literature.