Neuroepithelial cyst of the fourth ventricle. Case report

Developmental cysts lined by neuroepithelium are a distinctive form of neural tube dysgenesis. Neuropathological study of fourth ventricular cysts that caused symptomatic hydrocephalus indicated its neuroepithelial origin. The cyst arose from the ventral surface of cerebellar vermis. Evagination of the rhombencephalic roof and entrapment of a ventricular diverticulum beneath the cerebellar anlagen is proposed as a mechanism responsible for the extraordinary occurrence of neuroepithelial cysts within the fourth ventricle.