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Health condition · Clinically reviewed

Medulloblastoma, the most common childhood brain tumour - and how it is treated.

A cerebellar tumour that behaves very differently depending on its molecular subgroup. Early recognition, precise imaging and a specialist neuro-oncology team shape the outcome.

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A radiographer guides a patient onto the bed of an advanced 3 Tesla MRI scanner in a London imaging suite

Why trust this guide

  • 01

    Clinically reviewed

    Written by our editorial team and reviewed by a registered UK clinician before publication.

  • 02

    Sourced from guidance

    Checked against SIOP, CCLG and peer-reviewed sources you can see at the end.

  • 03

    Current for 2026

    Reflects modern UK guidance including WHO molecular subgrouping and risk-adapted therapy.

Key facts

Medulloblastoma at a glance.

The essentials, in plain English - what it is, the molecular subgroups, and how it's investigated and treated in the UK today.

  • What it is

    The most common malignant paediatric brain tumour - arising in the cerebellum, at the back of the skull (posterior fossa).

  • Who it affects

    Mainly young children, with a peak in early-to-mid childhood - though it can, rarely, occur in adults.

  • Molecular subgroups

    WNT-activated, SHH-activated, Group 3 and Group 4 - each with a different prognosis and treatment pathway under WHO classification.

  • Key symptom pattern

    Raised intracranial pressure (morning headache, vomiting) plus cerebellar signs - unsteady walking, clumsiness and abnormal eye movements.

  • Core investigation

    MRI of the brain and whole spine with contrast - essential before and after surgery to map the tumour and check for spread.

  • Foundation treatment

    Maximal safe surgical resection first, then risk-stratified radiotherapy and chemotherapy planned by a specialist paediatric neuro-oncology team.

Why this guide matters

Molecular biology now drives the treatment plan.

Medulloblastoma is no longer treated as one disease. The three points below shape everything else on this page.

  • Subgroup changes everything

    WNT-activated disease carries the best prognosis, while Group 3 with MYC amplification is the most aggressive - subgroup guides intensity of treatment.

  • Whole-spine imaging is essential

    Because the tumour can seed through the CSF, staging always includes the whole spine, not just the brain.

  • Age changes the approach

    Children under three are often managed with chemotherapy-only protocols to delay or avoid radiotherapy while the brain is still developing.

How the diagnosis is made

From first symptoms to a full molecular diagnosis.

The steps a UK paediatric neuro-oncology centre will normally follow, in order - so families know what to expect and why.

  1. 01

    Recognising

    Recognising the pattern

    Morning headache, vomiting and unsteady gait together should prompt urgent assessment - not a wait-and-see approach.

  2. 02

    Recognising

    Urgent MRI brain

    The first and most important test - it shows the posterior fossa mass and any obstructive hydrocephalus.

  3. 03

    Recognising

    Whole-spine MRI with contrast

    Performed alongside the brain scan - medulloblastoma can seed through the CSF, so the whole spine is checked for drop metastases.

  4. 04

    Confirming

    CSF diversion if needed

    A VP shunt or endoscopic third ventriculostomy relieves pressure from hydrocephalus, often before or during the operation for the tumour itself.

  5. 05

    Confirming

    Surgical resection and histology

    Tissue taken at surgery confirms the diagnosis under the microscope and starts the molecular subgrouping process.

  6. 06

    Confirming

    CSF cytology after surgery

    A lumbar puncture, done once it is safe, looks for tumour cells shed into the spinal fluid - never performed beforehand if pressure is raised.

  7. 07

    Planning

    Molecular subgrouping

    Specialist neuropathology defines WNT, SHH, Group 3 or Group 4 status - this shapes the whole treatment plan and outlook.

  8. 08

    Planning

    Chang staging and MDT planning

    Tumour extent and metastatic spread are staged, and a specialist paediatric neuro-oncology MDT sets the risk-adapted treatment plan.

Typical timeline: urgent imaging and surgery within days, with a full molecular diagnosis over the following one to two weeks.

Symptoms

What medulloblastoma actually looks like.

A combination of raised intracranial pressure and cerebellar signs, often developing over weeks. And the features that mean it's time to seek urgent care.

  • Morning headache

    Headache that is worse on waking or lying flat - a classic sign of raised intracranial pressure.

  • Vomiting, often without nausea

    Early-morning vomiting that can occur suddenly, sometimes relieving the headache briefly.

  • Papilloedema

    Swelling of the optic disc seen on eye examination - a sign of sustained raised pressure inside the skull.

  • Unsteady gait and ataxia

    Difficulty walking in a straight line or standing steadily - reflects cerebellar involvement.

  • Nystagmus and dysmetria

    Abnormal eye movements and poor coordination reaching for objects - both point to the cerebellum.

  • Cranial nerve palsies

    Double vision, facial weakness or swallowing difficulty if the tumour presses on the brainstem.

  • Spinal symptoms from CSF spread

    Back pain, leg weakness or bladder changes can signal leptomeningeal dissemination via the spinal fluid.

  • Red flag - the triad together

    Headache, vomiting and unsteadiness appearing together in a child warrant same-day urgent assessment.

Treatment

How medulloblastoma is treated in the UK.

Surgery first, then risk-adapted radiotherapy and chemotherapy - planned by a specialist paediatric neuro-oncology multidisciplinary team.

  • Maximal safe surgical resection

    The first and most important step - removing as much tumour as safely possible, performed by specialist paediatric neurosurgeons.

  • CSF diversion

    A VP shunt or endoscopic third ventriculostomy to relieve hydrocephalus, before, during or after tumour surgery as needed.

  • Risk stratification

    Age, extent of resection, metastatic status and molecular subgroup together define average-risk versus high-risk disease.

  • Craniospinal radiotherapy

    Standard for children over three, covering the whole brain and spine - dose can be reduced for average-risk WNT-activated disease.

  • Multi-agent chemotherapy

    Regimens vary by risk group and age, given alongside or after radiotherapy to reduce recurrence.

  • Infant chemotherapy-only protocols

    In children under three, chemotherapy-led approaches aim to delay or avoid radiotherapy to protect the developing brain.

  • Molecular-targeted therapy

    SHH-pathway inhibitors are an emerging option for relapsed SHH-subgroup disease, used selectively given growth-plate toxicity concerns in children.

  • Long-term survivorship care

    Ongoing monitoring of neurocognitive function, hearing, endocrine health and growth through dedicated survivorship clinics.

Genetics and survivorship

Some families need more than oncology alone.

Where SHH-activated disease is linked to Gorlin syndrome and a germline PTCH1 mutation, genetic counselling helps the family understand the wider implications. Once active treatment ends, long-term survivorship clinics take over - tracking neurocognitive development, hearing (platinum chemotherapy can be ototoxic), growth and hormone function for years afterwards, working alongside charities such as The Brain Tumour Charity.

What this guide is based on

The sources behind every claim on this page.

UK and international paediatric oncology guidance and specialist society standards, current at the time of last review.

Key references

Guidelines and standards we relied on.

A quiet reminder

This guide is for information, not medical advice.

Your paediatric oncology team knows your child's specific tumour, subgroup and history, and can tell you which parts apply to them. If in doubt, get seen urgently.

  • SIOP Europe (International Society of Paediatric Oncology). Medulloblastoma treatment guidelines.

  • CCLG (Children’s Cancer and Leukaemia Group). Medulloblastoma information and treatment protocols.

  • WHO Classification of Tumours of the Central Nervous System. Molecular subgrouping of medulloblastoma.

  • The Brain Tumour Charity. Medulloblastoma patient and family information.

Red flags

When symptoms need urgent attention.

Medulloblastoma is a paediatric emergency once suspected. These are the situations that need same-day specialist care.

  • Signs of raised intracranial pressure

    Persistent morning headache and vomiting in a child need urgent same-day medical assessment, not a routine appointment.

  • Rapid deterioration in coordination

    A sudden or fast-worsening unsteady gait is a strong signal for urgent brain imaging.

  • Reduced consciousness

    Drowsiness, confusion or difficulty rousing a child alongside headache is a neurosurgical emergency.

  • New cranial nerve signs

    Double vision, facial droop or swallowing difficulty suggest brainstem involvement and need urgent specialist review.

  • Spinal cord symptoms

    New back pain, leg weakness or loss of bladder control can indicate CSF-borne spread and need urgent whole-spine imaging.

  • Post-surgical fever or leaking wound

    Signs of shunt or wound infection after neurosurgery need same-day specialist review.

  • Suspected Gorlin syndrome

    A family history of basal cell carcinomas or jaw cysts alongside SHH-activated medulloblastoma should prompt genetics referral.

  • Mood or behaviour change during treatment

    Any marked change in mood or behaviour during chemotherapy or radiotherapy should be discussed promptly with the treating team.

  • Signs of relapse after treatment

    New headache, vomiting or neurological symptoms after finishing treatment need urgent re-assessment and imaging.

Living with it

A demanding journey, with a specialist team behind it.

Four things that make the biggest difference for families through treatment and beyond - staying close to the specialist centre, keeping every scan, watching for long-term effects, and reaching out for support.

A quiet reminder

Outcomes have improved enormously with molecular medicine.

Understanding the exact subgroup means treatment can be tailored - neither over- nor under-treating a child's specific tumour.

  1. 01 Team

    Lean on the specialist centre

    Care sits with a small number of UK paediatric neuro-oncology centres - stay closely connected with your named keyworker.

  2. 02 Monitor

    Keep every follow-up scan

    Surveillance MRI catches recurrence early, when treatment options are widest.

  3. 03 Support

    Long-term effects need attention

    Hearing, growth, learning and hormone function can all be affected - survivorship clinics track these for years.

  4. 04 Connect

    Charity support helps the whole family

    The Brain Tumour Charity and similar organisations offer practical and emotional support alongside medical care.

Frequently asked

Everything we get asked about medulloblastoma.

Quick answers on symptoms, staging, molecular subgroups and treatment.

  • What is medulloblastoma?

    It is the most common malignant brain tumour in children, arising in the cerebellum at the back of the skull. It is classified into WNT-activated, SHH-activated, Group 3 and Group 4 molecular subgroups, each carrying a different prognosis and treatment approach.

  • What are the first signs parents notice?

    Most commonly a combination of morning headache, vomiting and unsteadiness on the feet, sometimes with clumsiness or abnormal eye movements. These signs together, especially in a young child, should prompt urgent medical assessment.

  • Why is a whole-spine MRI needed as well as a brain scan?

    Medulloblastoma can spread through the cerebrospinal fluid to seed tumour deposits along the spine, known as drop metastases. Imaging the whole spine at diagnosis is essential for accurate staging and treatment planning.

  • Why do the molecular subgroups matter so much?

    WNT-activated tumours generally have the best outlook and can sometimes be treated with reduced-intensity therapy, while Group 3 tumours with MYC amplification tend to behave more aggressively. Subgroup status increasingly determines how intensive treatment needs to be.

  • Why is radiotherapy avoided in very young children?

    Craniospinal radiotherapy can affect the developing brain, particularly under the age of three. Infants are often treated with chemotherapy-only protocols first, to delay or avoid radiotherapy while the brain matures.

  • What does long-term follow-up involve?

    Survivors are monitored for years for hearing loss from platinum chemotherapy, growth and hormone changes, and neurocognitive effects, alongside regular surveillance imaging to check for recurrence.

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