Normal choroidal fissure of the left temporal lobe in coronal section. Note its relation with the temporal horn of lateral ventricle and the choroid plexus.
The choroid plexus is medially displaced in the case of neuroepithelial ventricular origin.
The choroid plexus is laterally displaced in the case of cyst of arachnoid origin from the choroidal fissure.
Case Discussion
Arachnoid cyst represents 1% of all intracranial masses, with the choroidal fissure cyst representing approximately 7.4% of the total.
They can be from the neuroepithelial or arachnoid origin. The choroid plexus is an important landmark to determine its origin from the choroidal fissure or the temporal horn. You will see the choroid plexus laterally displaced in the case of arachnoid origin from choroidal fissure or medially displaced in the case of neuroepithelial ventricular origin.