Fourth Ventricle Choroid Plexus Xanthogranuloma Causing Hydrocephalus.

Xanthogranulomas of the choroid plexus are discovered incidentally on autopsy in 1.6 to 7% of cases, and are typically found in the lateral ventricles. Very rarely, however, they can become symptomatic because of obstruction of the ventricular system, and these tend to be found in the third ventricle. There has only been one published case of fourth ventricle choroid plexus xanthogranuloma. We present a second case to add to the sparse literature of a symptomatic choroid plexus xanthogranuloma of the fourth ventricle causing hydrocephalus. This case demonstrates the difficulty of differentiating these lesions from other intracranial masses including aneurysms.