Synovial cyst of the thoracic spine causing myelopathy.

STUDY

DESIGN

Pre- and postoperative follow-up of a patient with progressive myelopathy caused by a thoracic synovial cyst developing within 6 months.

OBJECTIVE

To present the natural history of a developing thoracic synovial cyst and to highlight this unusual case.

SUMMARY OF BACKGROUND DATA: Thoracic synovial cysts are a rare finding and can produce myelopathy from spinal cord compression. The patient presented with progressing spasticity and sensory loss of both legs. Hereditary motor-sensory neuropathy was suspected and excluded by a molecular genetic examination. The cause of deterioration was finally found in an MRI of the thoracic spine revealing the rapid growth of a synovial cyst that had been detected in a previously performed MRI 6 months earlier.

METHODS

Clinical and MRI details are presented documenting the natural history and development of a thoracic synovial cyst causing myelopathy.

RESULTS

The thoracic synovial cyst was successfully decompressed. Stabilization and fusion were not performed. The myelopathy resolved after surgery and the patient stays well in the 6-months follow-up.

CONCLUSION

Although thoracic synovial cysts are a rare finding, they have to be considered as a source for progressive myelopathy. If an MRI of the spine does not reveal any pathologies, it should be repeated even after a short period of time if the patient's condition deteriorates, continuously to detect newly developed findings.