Arachnoid cyst, fourth ventricle
Arachnoid cysts are relatively frequent pathologies in the central nervous system, first described in 1831 by Bright, they are collections whose content may be identical to cerebrospinal fluid or with certain variations1 . In this case an Arachnoid Cyst is described in a rare location, fourth ventricle, only 13 cases of this topography have been reported by this moment. These cysts are usually intra arachnoid, benign, congenital, non-tumor and extraaxial lesions1 . This is a 47-year-old woman who has very slow onset symptoms, which in the three weeks prior to hospitalization began to be disabling, which is why an MRI is performed, in which an intraventricular cystic image is observed that It displaces the brain stem rostrally, which is why surgical management of the lesion is decided.