Ligamentum flavum cyst.

INTRODUCTION

Although magnetic resonance imaging (MRI) of ligamentum flavum and other spinal cysts have been well described, the role of contrast enhancement in this diagnosis has been neglected. We describe such a case and correlate the MRI findings with the histopathology.

CASE REPORT

A 71-years-old woman was admitted with of neurogenic lumbar claudication. X-rays of the lumbar spine showed degenerative changes with scoliosis. Lumbar magnetic resonance imaging demonstrated a L3/4 extradural cystic mass. An L3 laminectomy was performed and the mass excised. The histopathological diagnosis was consistent with a ligamentum flavum cyst. Postoperatively, the patient's symptoms resolved completely.

CONCLUSION

The possibility of a ligamentum flavum cyst should be considered whenever a hyperintense extradural mass with a peripheral hypointense rim on T2 weighted and slightly contrast enhanced peripheral rim on T1 weighted MRI is identified in a patient with degenerative changes of the lumbar spine.