RESUMEN
BACKGROUND: Choroid plexus cysts (CPCs) are a type of neuroepithelial cysts, benign lesions located more frequently in the supratentorial compartment. Symptomatic CPCs in the posterior fossa are extremely rare and can be associated with obstructive hydrocephalus. CASE DESCRIPTION: A previously healthy elderly woman suffered intermittent attacks of headache and vomiting associated with gait instability. Magnetic resonance imaging documented a large cystic lesion occupying all the fourth ventricle. An endoscope-assisted fenestration of the lesion through a telovelar approach determined only temporary improvement, hence a second surgery with gross total resection of the cyst was performed, with successful long-term clinical and radiologic resolution. Histology revealed CPC. CONCLUSIONS: Fourth ventricle symptomatic CPCs are extremely rare lesions, especially in the elderly. Their presence must be carefully evaluated as a possible rare cause of intermittent obstructive hydrocephalus. Even though cyst fenestration with restoration of the cerebrospinal fluid pathway represents the best treatment in the majority of cases, a more aggressive resection is sometimes necessary.