[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [General pathology](https://durgical.com/en/general-pathology/) › [Central nervous system](https://durgical.com/en/general-pathology/areas/cns/) › CNS tumours: an overview

# CNS tumours: an overview

- Topic

Brain tumours are now named by both their look and their genes; even ‘benign’ ones can kill by their location.

Updated Nov 12, 2026

## Key points

- Adults: metastases are the most common brain tumours; among primaries, meningioma and glioblastoma lead.
- Children: brain tumours are the commonest solid tumours; pilocytic astrocytoma, medulloblastoma and ependymoma are classic, many in the posterior fossa.
- Integrated diagnosis example: ‘astrocytoma, IDH-mutant, CNS WHO grade 3’.
- Diffuse gliomas infiltrate the brain and cannot be cured by surgery alone; circumscribed tumours (pilocytic astrocytoma) often can.
- Spread: local infiltration and CSF seeding (‘drop metastases’ to the spine); spread outside the CNS is rare.

## What it is

Tumours of the CNS differ from tumours elsewhere. The WHO classification gives an integrated diagnosis that joins histology, grade and molecular findings such as IDH mutation or 1p/19q codeletion. Grades run from 1 to 4 within each tumour type. Location matters as much as biology: a low-grade tumour in the brainstem may be fatal, and even diffuse low-grade gliomas infiltrate widely. Primary CNS tumours rarely spread outside the nervous system, but they can seed along the CSF. In adults most are supratentorial; in children many arise in the posterior fossa.

## Key facts

- Pituitary neuroendocrine tumours, craniopharyngioma and pineal tumours are covered with the endocrine system; schwannomas and neurofibromas with peripheral nerve.
- Clinical signs come from raised pressure (headache, vomiting, papilledema), seizures and focal deficits.

## The main CNS tumours at a glance

| Tumour | Typical age | Typical site | Molecular marker |
| --- | --- | --- | --- |
| [Glioblastoma, IDH-wildtype](https://durgical.com/en/conditions/glioblastoma/) | Older adults | Cerebral hemispheres, crosses corpus callosum | EGFR amplification, TERT promoter, +7/−10 |
| Astrocytoma, IDH-mutant | Young adults | Hemispheres, frontal | IDH1/2, ATRX loss, TP53 |
| Oligodendroglioma | Adults | Frontal lobe, cortex | IDH plus 1p/19q codeletion |
| [Pilocytic astrocytoma](https://durgical.com/en/conditions/childhood-brain-tumours/) | Children, young adults | Cerebellum, optic pathway | BRAF fusion (KIAA1549-BRAF) |
| [Medulloblastoma](https://durgical.com/en/conditions/childhood-brain-tumours/) | Children | Cerebellum (vermis) | WNT, SHH, groups 3 and 4 |
| Ependymoma | Children (fourth ventricle), adults (spinal cord) | Ventricles, cord | ZFTA fusion, PFA/PFB groups, MYCN |
| [Meningioma](https://durgical.com/en/conditions/meningioma/) | Adults, more women | Dura | NF2 loss |
| [Primary CNS lymphoma](https://durgical.com/en/conditions/primary-central-nervous-system-lymphoma/) | Older adults, immunosuppressed | Periventricular | Large B cells, EBV in immunosuppression |
| [Metastasis](https://durgical.com/en/conditions/brain-metastases/) | Adults | Grey-white junction | Depends on primary |

## Clinical notes

- MRI with contrast is the main imaging test; biopsy with molecular testing gives the diagnosis.
- Treatment combines surgery, radiotherapy and chemotherapy depending on type, grade and molecular profile.

## Memory aid

In the brain, address and genes count as much as the face under the microscope.

## Test yourself

Think of the answer, then tap the question to see it.

## What is the most common tumour found in the adult brain?

Metastasis from a cancer elsewhere, most often lung, breast or melanoma.

## What does an integrated diagnosis of a CNS tumour combine?

Histologic type, CNS WHO grade and molecular findings such as IDH status or 1p/19q codeletion.

## How do primary brain tumours usually spread?

By local infiltration and seeding through the CSF; spread outside the CNS is rare.

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[More Pathology questions →](https://durgical.com/en/practice/?f=pathology)

## Connections

## Related 15

- [Adult diffuse gliomas](https://durgical.com/en/general-pathology/adult-diffuse-gliomas/)
- [Pilocytic astrocytoma](https://durgical.com/en/general-pathology/pilocytic-astrocytoma/)
- [Ependymal, choroid plexus and glioneuronal tumours](https://durgical.com/en/general-pathology/ependymal-choroid-plexus-and-glioneuronal-tumours/)
- [Medulloblastoma and other embryonal tumours](https://durgical.com/en/general-pathology/medulloblastoma-and-other-embryonal-tumours/)
- [Primary CNS lymphoma](https://durgical.com/en/general-pathology/primary-cns-lymphoma/)
- [Meningioma](https://durgical.com/en/general-pathology/meningioma/)
- [Brain metastases and paraneoplastic syndromes](https://durgical.com/en/general-pathology/brain-metastases-and-paraneoplastic-syndromes/)
- [Familial tumour syndromes of the nervous system](https://durgical.com/en/general-pathology/familial-tumour-syndromes-of-the-nervous-system/)
- [Pituitary neuroendocrine tumours (PitNETs): overview](https://durgical.com/en/general-pathology/pituitary-neuroendocrine-tumours-overview/)
- [Suprasellar and pineal tumours: craniopharyngioma](https://durgical.com/en/general-pathology/suprasellar-and-pineal-tumours-craniopharyngioma/)
- [Schwannoma and neurofibromatosis type 2](https://durgical.com/en/general-pathology/schwannoma-and-neurofibromatosis-type-2/)
- [Naming tumours: -oma, carcinoma, sarcoma, and the misleading names](https://durgical.com/en/general-pathology/naming-tumours-oma-carcinoma-sarcoma-and-the-misleading-names/)

## See all 15

- [Grading and staging: what TNM means](https://durgical.com/en/general-pathology/grading-and-staging-what-tnm-means/)
- [Molecular pathology: PCR, FISH, sequencing and liquid biopsy](https://durgical.com/en/general-pathology/molecular-pathology-pcr-fish-sequencing-and-liquid-biopsy/)
- [Tumours of infancy and childhood](https://durgical.com/en/general-pathology/tumours-of-infancy-and-childhood/)

## Related conditions 7

- [Glioblastoma](https://durgical.com/en/conditions/glioblastoma/)
- [Childhood brain tumours (medulloblastoma, pilocytic astrocytoma, craniopharyngioma)](https://durgical.com/en/conditions/childhood-brain-tumours/)
- [Brain metastases](https://durgical.com/en/conditions/brain-metastases/)
- [Meningioma](https://durgical.com/en/conditions/meningioma/)
- [Primary central nervous system lymphoma](https://durgical.com/en/conditions/primary-central-nervous-system-lymphoma/)
- [Pituitary adenoma](https://durgical.com/en/conditions/pituitary-adenoma/)
- [Vestibular schwannoma (acoustic neuroma)](https://durgical.com/en/conditions/vestibular-schwannoma/)

[← All of general pathology](https://durgical.com/en/general-pathology/)

Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.

Sources: [Central Nervous System Tumors Treatment (PDQ®)–Health Professional Version](https://www.cancer.gov/types/brain/hp/adult-brain-treatment-pdq) (National Cancer Institute, 2026).

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Source: https://durgical.com/en/general-pathology/cns-tumours-an-overview/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/general-pathology/cns-tumours-an-overview/