Background: Intracranial ependymal cysts are rare lesions generally located in the cerebral parenchyma, juxtraventricular region, or subarachnoid space; but no case of a purely intraventricular ependymal cyst has been reported.
Case report: A case of intraventricular ependymal cyst presenting with symptoms of psychosis is reported. The patient's symptoms resolved almost completely following endoscopic resection of the cyst. The embryologic basis of the development of an ependymal cyst inside the ventricle and its histologic characteristics are discussed. Possible mechanism of psychosis in this case is also discussed.
Conclusion: Minimally invasive techniques, as in this case, may be useful in refractory psychotic cases with cystic lesions.