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