| Entity | WHO grade | Typical demographics/site | Molecular features | Clinical behavior | Standard management |
|---|---:|---|---|---|---|
| Choroid plexus papilloma (CPP) | 1 | Intraventricular choroid plexus tumor; often pediatric but also occurs in adults; molecular subgrouping supports pediatric supratentorial low-risk and adult infratentorial low-risk groups (ontology/site labels requiring validation) (pqac-00000001, pqac-00000017) | Usually lacks recurrent driver mutations; adult CPTs may harbor TERT promoter mutations (7/28 adults across CPTs, associated with shorter PFS) or rare CCDC47-PRKCA fusion in aggressive adult CPP; chromosome 9 amplification reported as CPP-specific in one 2024 multiomics cohort (pqac-00000017) | Generally benign/low-risk; favorable prognosis relative to CPC; recurrence risk lower than aCPP/CPC but molecular subgroup can refine risk (pqac-00000001, pqac-00000017) | Maximal safe surgical resection is standard; adjuvant therapy usually not required after complete resection (general CPT management evidence), with radiotherapy considered selectively in incompletely resected/recurrent cases (pqac-00000001) |
| Atypical choroid plexus papilloma (aCPP) | 2 | Pediatric intraventricular tumor; example pediatric case with hydrocephalus and ataxia; grouped with low-risk or high-risk methylation classes depending age/site, requiring molecular risk assessment (pqac-00000005, pqac-00000017) | Example tumor had BRD1 frameshift deletion with gains of chromosomes 12/18/20 and losses of 13q/22q; p53 IHC may be negative; no recurrent universal somatic driver established (pqac-00000005, pqac-00000001) | Intermediate behavior; higher recurrence risk than CPP; histology alone can be insufficient for risk stratification, so methylation profiling may add prognostic value (pqac-00000001, pqac-00000017) | Surgery is primary treatment; adjuvant radiotherapy/chemotherapy individualized, especially for subtotal resection or higher-risk molecular features; one reported case received 36 Gy RT and remained disease-free at 78 months (pqac-00000005) |
| Choroid plexus carcinoma (CPC) | 3 | Rare aggressive malignant CPT of infancy/early childhood; median diagnosis age about 3 years, annual incidence about 0.3 per million; often supratentorial/pediatric high-risk methylation class; highly vascular, invasive, CSF-disseminating (pqac-00000003, pqac-00000017) | TP53 is the dominant recurrent alteration: TP53 mutations in 7/47 CPTs overall and frequent in CPC; germline TP53/Li-Fraumeni common, with estimates of 50-80% in children with CPC from LFS guidelines; LOH at TP53, hyperdiploidy/genomic instability, whole-chromosome CNAs, chromosome 1 amplification, mutually exclusive TP53 and EPHA7 point mutations in one 2024 cohort; hypomethylation of repeat elements; multiciliogenesis program disruption (GMNC-MCIDAS), NOTCH/SHH involvement, MYC/TP53 cooperation in models (pqac-00000003, pqac-00000004, pqac-00000009, pqac-00000017) | Most aggressive subtype; recurrent/metastatic propensity and worse survival, especially with TP53 mutation. In SJYC07, 5-year PFS 61.5% and OS 68.4%; TP53-wild-type 5-year PFS 100% vs 28.6% for TP53-mutant tumors (pqac-00000002, pqac-00000003) | Maximal safe resection plus intensive chemotherapy is standard backbone; SJYC07 used high-dose methotrexate-containing non-myeloablative therapy with durable survival in >50% of patients. Radiotherapy is individualized and may be avoided or minimized in germline TP53 carriers because of secondary malignancy risk (pqac-00000002, pqac-00000003, pqac-00000013) |
| Choroid plexus tumor molecular subgroup: pediatric A (pedA) | Not a WHO histologic grade; methylation subgroup | Young age, supratentorial, favorable-risk subgroup (ontology label requiring validation) (pqac-00000017) | Defined by DNA methylation profiling rather than unique recurrent driver mutation; part of 3-group epigenetic framework (pqac-00000017) | Favorable prognosis relative to pedB (pqac-00000017) | Supports risk stratification alongside histology; not a standalone treatment entity (pqac-00000017) |
| Choroid plexus tumor molecular subgroup: pediatric B (pedB) | Not a WHO histologic grade; methylation subgroup | Predominantly pediatric high-risk subgroup; includes many CPCs and some histologically lower-grade CPTs; frequent recurrences (pqac-00000002, pqac-00000017) | Frequent chromosomal copy-number alterations; S/G2/M hyperproliferative enrichment on snRNA-seq; methylation-defined high-risk biology (pqac-00000002, pqac-00000007, pqac-00000017) | Higher risk of recurrence/aggressive course than pedA/adult subgroup, even when histology is not overtly carcinoma (pqac-00000017) | Indicates need for closer surveillance and may justify therapy intensification in future stratified protocols (pqac-00000002, pqac-00000017) |
| Choroid plexus tumor molecular subgroup: adult | Not a WHO histologic grade; methylation subgroup | Adult, often infratentorial low-risk subgroup (ontology/site label requiring validation) (pqac-00000017) | TERT promoter mutations found in 7/28 adult CPTs and associated with shorter PFS; rare CCDC47-PRKCA fusion described in aggressive adult CPP; adult tumors showed higher macrophage proportion by snRNA-seq (22.4% vs 8.2% in pediatric high-risk tumors) (pqac-00000007, pqac-00000017) | Usually more favorable than pediatric high-risk subgroup, but adverse molecular lesions can signal worse course (pqac-00000017) | Primarily surgical management; molecular profiling may identify adults needing closer follow-up (pqac-00000017) |


*Table: This table summarizes the main choroid plexus neoplasm subtypes and molecular subgroups using only evidence gathered in the conversation. It is useful for quickly comparing histology, demographics, molecular findings, clinical behavior, and management while flagging site/ontology labels that require validation.*