Presentation
Chronic back pain. Sharp pain radiating to the right leg.
Patient Data
Intraspinal extradural cyst with a rather thick, T1-hypointense capsule and somewhat inhomogeneous content. Marked displacement of the thecal sac and cauda roots. Degenerative disease of the discs and facet joints L4/5/S1 which also show some effusion. Lumbarization of the 1st sacral vertebra.
Case Discussion
Cyst or ganglia of the facet joints are well known, albeit rare. Typically, they are only one aspect of chronic degenerative lumbar spinal disease. If protruding into the spinal canal or an intervertebral foramen, they may cause symptoms similar to a disc hernia. MRI is the method of choice for their detection 1.