Intraventricular neoplasms derived from choroid plexus epithelium including choroid plexus papilloma (WHO grade I), atypical choroid plexus papilloma (WHO grade II), and choroid plexus carcinoma (WHO grade III). The vast majority are sporadic, though rarely arise in association with hereditary cancer predisposition syndromes, including the Li Fraumeni and Rhabdoid Predisposition Syndromes, with germline mutations of TP53 and hSNF5/INI1/SMARCB1 respectively. Choroid plexus papillomas (CPP) are also a component of Aicardi syndrome, the affected patients showing agenesis of the corpus callosum, chorioretinal lacuna, and infantile spasms. Rarely CPP arise in the context of von Hippel-Lindau disease. Choroid plexus papillomas are at least five times more common than carcinomas (CPC).