Definition: Choroid plexus papilloma is a benign solid neoplasm arising from the neuroepithelial cells of the choroid plexus epithelium, growing within the ventricles and producing Cerebrospinal fluid (CSF).

Epidemiology: This tumor primarily affects children, with about 80% of all choroid plexus tumors occurring in the first decade of life. Most choroid plexus tumors occur sporadically, except in two hereditary syndromes—Aicardi syndrome (defect in X chromosome leading to malformations) and Li-Fraumeni syndrome (autosomal dominant syndrome linked to germline mutations of p53 tumor suppressor gene).

Affected age group: Pediatric CPPs tend to occur in the lateral, or less frequently in the third, ventricle whereas the fourth ventricle is more commonly involved in adult CPPs. A meta-analysis of CPP location found that the median patient age was 1.5 years for lateral/third ventricles, 22.5 years for fourth ventricle, and 35.5 years for cerebellopontine angle.

Molecular and genetic profile: This tumor is often associated with MGMT promoter methylation and less commonly with Aicardi syndrome (X-linked syndrome with triad of corpus callosal dysgenesis, chorioretinal lacunae, and infantile spasms).

CSF markers: None.

Clinical features and standard therapy: Gross total resection usually achieves cure of choroid plexus papilloma, with a 5-year survival of near 100% or 100%. However, recurrence locally or at a distant site, especially when the tumor is incompletely resected, is not unusual and contributes to shorter survival.