Combined choroid plexus cyst and choroid plexus lipoma in the lateral ventricle causing unilateral ventriculomegaly: a case report

Choroid plexus cysts (CPCs) are the most common neuroepithelial cysts, but rarely present with neurological signs or symptoms. Intracranial lipomas are generally seen at an interhemispheric location, and solitary choroid plexus lipomas (CPLs) have been reported in only a few cases. Here we report a symptomatic case of a 39-year-old woman with combined CPC and CPL on the lateral ventricle. She presented with a headache associated with a mass lesion and multiple cysts on her right lateral ventricle and subsequently developed unilateral ventriculomegaly. The mass demonstrated hypointensity on T1-weighted magnetic resonance imaging (MRI) and homogeneous enhancement on contrast-enhanced MRI. Histopathologically, the resected lesion was composed of multiple cysts lined with a single layer of cuboidal epithelial cells and numerous mature fat cells in the stromal component. The stromal component also included the distinct foci of arachnoid cells, suggesting that mature fat cells are derived from the arachnoid cell in the choroid plexus. To our knowledge, this is the first case of combined CPC and CPL.