CT / MRI features of an intraventricular epidermoid cyst with obstructive hydrocephalus. The location within the 4th ventricle is the second most common after the cerebellopontine angle and account for around 17% 1. The differential diagnosis of an epidermoid cyst includes mainly an arachnoid cyst which follows the CSF signal on all sequences including FLAIR and DWI whereas an epidermoid cyst shows a high signal on DWI.
Additional contributor: R Bouguelaa, MD.