Lumbar intraspinal synovial cysts of different etiologies: diagnosis by CT and MR imaging.

Intraspinal synovial cysts arises from a facet joint and may cause radicular symptoms due to nerve root compression. In the present study, three surgically and histologically proved cases of synovial cyst of the lumbar spine with different etiology are described. The purpose of this report is to illustrate the imaging features of various etiologies of intraspinal synovial cysts allowing a correct preoperative diagnosis. Review of the literature enables us to say that to our knowledge, there is no reported article collecting the imaging findings of intraspinal synovial cysts with different etiologies. Only single cases with rheumatoid arthritic or traumatic origin have been reported to date. We believe that computed tomography and particularly magnetic resonance imaging are the methods of choice which provide the most valuable diagnostic information.