Cyst of the Ligamentum Flavum Associated With Spondylolisthesis: Rare Case Report and Literature Review

Abstract

Cysts of the ligamentum flavum are rare and unusual causes of spinal compression and usually are seen in persons over 50 years of age. In this study, we report a case of an epidural cyst located in the ligamentum flavum, which contributed to spinal stenosis in a 48-year-old woman with the neurogenic lumbar claudication. Radiographs of the lumbar spine showed degenerative changes with L4/L5 spondylolisthesis. Lumbar magnetic resonance imaging showed an extradural cystic mass at the L4-L5 intervertebral space and canal stenosis at the L4-L5 space. Posterior lumbar instrumentation with transpedicular screw fixation and fusion and then L4 laminectomy were performed and the mass was excised. The histopathologic diagnosis was consistent with a ligamentum flavum cyst. Postoperatively, the patient's symptoms were resolved completely. This case was the first description of cyst of the ligamentum flavum associated with spondylolisthesis, with regard to the literature reviews.