Pediatric Colloid Cyst Of Third Ventricle

  • Etiology: Benign epithelial lined cyst containing mucin, old blood (hemosiderin), cholesterol and various ions which is located at the Foramen of Monro
  • Imaging CT:
    — Lesion is best seen on CT
    — Well defined high density lesion in the anterosuperior third ventricle at the Foramen of Monro on unenhanced CT
  • Imaging MRI: Variable appearance
    — T1WI: Often hyperintense
    — T1WI post contrast: May have peripheral rim enhancement
    — T2WI: Often isointense
  • DDX:
  • Complications: If large enough can cause acute obstructive hydrocephalus
  • Treatment: Surgical
  • Clinical: Usually asymptomatic but may present with acute obstructive hydrocephalus

Radiology Cases of Colloid Cyst of Third Ventricle

CT of colloid cyst
Axial CT without contrast of the brain shows a small, round, high density lesion in the midline in the anterior superior aspect of the third ventricle at the Foramen of Monro. The lesion could not be seen on an MRI performed at the same time.