Origin- Intracranial lipomas represent rare developmental malformations of the nervous system. They result from lipomatous differentiation of the persistent meninx primitiva, the mesenchymal derivative of the embryonic neural crest which envelopes the developing embryo. Since lipomas are postulated to develop in areas of tardy / incomplete resorption of the meninx primitiva (the cavitation of which result in formation of subarachnoid space), vessels and cranial nerves frequently traverse these malformations.

Lipomas are usually found in close apposition to the subjacent brain tissue. Lipomas do not grow; however they hypertrophy in tandem with the somatic growth.

Location - Inter-hemispheric lipomas constitute 40% to 50% of intracranial lipomas and are frequently associated with dysgenetic corpus callosum. Other associated findings include encephalocele, focal parenchymal hypoplasia, absent septum pellucidum and lipomas at other sites.

Clinical manifestations include seizures and headache. Intracranial lipomas especially the interhemispheric lipomas have been described in patients with midline craniofacial anomalies.

Association Choroid plexus lipomas of the lateral ventricle occur frequently in with pericallosal lipomas. The primitive meninx follows the choroidal fissure (to which the developing choroid plexus is attached to) into the lateral ventricle, thus contributing to the choroidal lipomas.