Discal cyst of the lumbar spine: MR imaging features.

We describe MR imaging features of discal cyst of the lumbar spine in nine patients who presented with low back pain and leg pain. Discal cyst of the lumbar spine has characteristic MR imaging features different from other epidural cysts: a ventrolateral extradural cyst attached to a herniated lumbar disc, consisting of a thick fibrous capsule without disc material, and having occasional extension into the lateral recess with rim enhancement on contrast-enhanced MR imaging.