Filar Cyst

  • Etiology: Congenital
  • Imaging: Cyst in filum terminale
  • DDX:
  • Complications:
  • Treatment: No followup needed in asymptomatic neonates and infants
  • Clinical:
    — Common normal variant

Radiology Cases of Filar Cyst

US of filar cyst
Sagittal US of the spine (above) shows the conus medullaris to terminate normally at the L1-L2 level. A hypoechoic cystic structure is seen just inferior to the conus and is better seen on the zoomed image (below).
US of filar cyst
Sagittal (above) and transverse (below) US of the spine show an oval anechoic structure just inferior to the tip of the conus of the spinal cord.