Presentation
Progressive positional headache not improving with medication.
Patient Data
There is a midline homogeneous hyperdense rounded mass lesion within the anterior third ventricle at level of foramen of Monro. It measures 16 x 16 x 19 mm in maximum anteroposterior, transverse and craniocaudal dimensions. There is marked dilation of supratentorial ventricular system with diffuse periventricular hypodensity indicating CSF permeation secondary to active obstructive hydrocephalus.
Case Discussion
The constellation of imaging findings described above that are characteristic of third ventricle colloid cyst resulting in obstructive hydrocephalus.