Cyst of the Ligamentum Flavum-Case Report-

Abstract

An 86-year-old man presented with intermittent claudication caused by a cyst of the ligamentum flavum. Lumbar magnetic resonance imaging demonstrated an extradural cystic mass at the L5-S1 intervertebral space and canal stenosis at the L4-5 space. L-5 laminectomy and flavectomy at the L4-5 and L5-S1 spaces were performed, and the cystic mass was excised. The histological features were consistent with cyst of the ligamentum flavum. The histological diagnosis was ganglion cyst of the ligamentum flavum. After surgery, claudication completely disappeared and the patient made a good recovery.

Lumbar Intraspinal Extradural Ganglion Cysts

“…Necrotic tissues, histiocyte infiltration, hemosiderin deposits, and neovascularization were also present in the wall. There should not be a true synovial lining 1,10,16,19) . The involvement of the facet joints associated with intraspinal cysts may influence on the treatment of strategy.…”

“…However, the ganglion cysts have no correlation with segmental instability and connection to facet joints. Therefore, simple excision of the ganglion cyst could be successful through minimal access 1,10,15,19) .…”

“…The "juxtafacet cyst" has been the most common entity of intraspinal cysts and encompasses the synovial cyst and ganglion cyst 12) . Extensive studies have been performed about the synovial cyst, however, very little has been known about the intraspinal extradural ganglion cyst 1,2,19) . Two types of cysts share common symptomatic and radiologic characteristics but different histological background.…”

“…Therefore, new name has been introduced to replace the "juxtafacet cyst" widely used since Kao first employed 6,12) . Regarding the ganglion cyst, many authors used various names including facet cyst, posterior longitudinal ligament (PLL) cyst, disc cyst or ligament flavum (LF) cyst depending on the origin 1,10,11,19) . On the other hand, some authors used the synovial cyst as a representative of the juxtafacet cysts including the ganglion cyst 20,22) .…”

“…Synovial cysts are based on the laxity of the synovial capsule of the facet joints and frequently associate with spinal instability 8) . The ganglion cyst is believed to arise from degenerated ligaments including the PLL and LF in the mobile spine 1,2,15,19) . We use "ganglion cyst", if the cyst originated from the ligamentous structures and lacked a true synovial lining without continuity to the facet joint, because they have common pathology regardless of the origin.…”