Ligamentum Flavum Cyst - A Rare Cause of Lumbar Canal Stenosis: A Case Report with Review of Literature

Abstract

Lumbar spinal stenosis is most common entity coming to spine out-patient department which may present with complaint of back pain with lower limbs neurogenic claudication, caused by degenerative disc conditions or to facet joint hypertrophy or ligamentum flavum thickening. We represent a case report of a patient suffering from low back pain with worsening neurogenic claudication. Imaging showing a cystic lesion at L3-4 spinal level with no lysthesis pinching the traversing nerve root who undervent minimal invasive tubular transforaminal lumbar interbody fusion. Intraoperatively, a cystic mass originating from ligament flavum with yellow jelly fluid adherent to dura and no communication with subarachnoid space or facet joint was found. Histologically, these cysts represent a distinct entity different from synovial cysts in terms of devoid of epethelial lining. To differentiate in cyst outlines and origin is very helpful in preoperative planning as even complete removal of ligamentum flavum cyst does not damage the facet joint and no fixation is required in these cases as compared to facetal cyst which represents instability and fixation is mandatory.