多発性に発生した腰椎椎間板嚢腫の１例

Abstract

Intraspinal canal cysts of the lumbar spine were named “discal cysts” by Toyama in recent years. We are reporting a case of multiple discal cysts of the lumbar spine. The patient was a 24-year-old man. His complaint started with low back pain and left thigh pain. On admission, neurological examination suggested the left L5 radiculopathy. The cysts were detected at bilateral L4/5 by Magnetic Resonance Imaging (MRI), Discogram and CT-discogram (CTD). In MRI, the cysts showed low intensity with T1-weighted imaging, high intensity with T2-weighted imaging, and ringed enhancement effect with Gadolinium. In the Discogram and CTD, the cysts were connected with the intervetebral disc.Upon operation, we found that the cyst was dark red, very fragile, and adhered to the L5 nerve root and intervertebral vein. The cyst contained blood of a pinkish color. There was no herniation. In the histological findings, there were mostly fibrous tissues and partially with hemosiderin in the cyst wall.It is considered that the base of the discal cyst was associated with mechanical pressure on a slightly degenerated intervertebral disc. The mechanical pressure causes the peridural membrane to tear off the intervertebral body, inducing rupture of the anterior internal plexus, which results in hematoma and cyst.