Raised Intracranial Pressure with Obstructive Hydrocephalus from a
Third Ventricle Colloid Cyst
Rabih Hage, MD Valérie Biousse, MD
Fundus Photographs
Bilateral severe optic nerve head edema with normal visual acuity and enlarged blind spots in a 24 year-old man with 2 weeks of severe headaches, suggesting increased intracranial pressure
Figure 1
Right eye Left eye
T1-Weighted Axial Brain MRI (without contrast)
Dilation of both lateral ventricles (yellow arrows) suggesting hydrocephalus
Figure 2a
T1-Weighted Axial Brain MRI (without contrast)
Dilation of both lateral ventricles (yellow arrows) suggesting hydrocephalus
Figure 2b
There is a T1 isointense lesion within the third ventricle (yellow circle)
Figure 3
T1-Weighted Axial Brain MRI (without contrast)
This midline sagittal cut demonstrates several radiologic signs of raised intracranial pressure
Figure 4
T1-Weighted Sagittal Brain MRI (without contrast)
Signs of Raised Intracranial Pressure: Obstructive Hydrocephalus
Dilation of the lateral ventricles with normal sized (or even small) fourth ventricle (yellow arrow), suggesting an obstruction at the level of the third ventricle (foramen of Monro)
Figure 4a
Signs of Raised Intracranial Pressure: Cerebellar Tonsils Herniation
Displacement of the cerebellar tonsils (arrow) below the foramen magnum (dashed yellow line)
Figure 4b
Signs of Raised Intracranial Pressure: Flattening of the Pituitary Gland
The sella has a shallow shape (yellow arrows), and the pituitary appears flat (blue arrow)
Figure 4c
Effacement of the suprasellar cistern (yellow arrow)
Figure 4d
MRI Signs of Raised Intracranial Pressure: Effacement of the Suprasellar Cistern
Sagittal Brain MRI Showing a Mass in the Third Ventricle
T1 isointense (5a – yellow circle) and T2 hyperintense (5b – red circle) lesion within the third ventricle and the region of the foramen of Monro, suggesting a colloid cyst
Figure 5a Figure 5b
Axial Brain MRI Showing a Mass in the Third Ventricle
Figure 6a Figure 6b
T1 isointense (6a – yellow circle) and T2 (FLAIR sequence) hyperintense (6b – red circle) lesion within the third ventricle and the region of the foramen of Monro, suggesting a colloid cyst
Final diagnosis
Colloid cyst of the third ventricle at the level of the foramen of Monro, complicated by severe
obstructive hydrocephalus and raised intracranial pressure with headaches and
papilledema