Ligamentum flavum cyst

  • Arise from or partially embedded within the ligamentum flavum
  • Seldom seen
  • Related to necrosis or myxoid degeneration in a hypertrophied ligamentum flavum
  • Chronic degenerative changes followed by repetitive hemorrhages will form degenerative cysts
  • These small cysts aggregate to form a single large cyst
Imaging
  • Typical location: L4-5
  • Extradural intraspinal mass in close relation to ligamentum flavum
  • No rim calcification (unlike juxtafacet cysts)
  • Sharply delineated
  • Round to ovoid
  • High T2 signal with low intensity rim. Rim enhances with gadolinium
Read more

Baker, James K., and Gregory W. Hanson. “Cyst of the ligamentum flavum.” Spine 19.9 (1994): 1092-1094.

Cakir, Ertugrul, et al. “Ligamentum flavum cyst.” Journal of Clinical Neuroscience 11.1 (2004): 67-69.