DIPG (pontine)

A diffuse midline glioma in the pons, a part of the brain stem. It is most often found in children. How it is found, and why surgery cannot remove it. What radiation does. And what to ask about dordaviprone for a tumor in the pons.

The short version

DIPG is a fast-growing tumor in the pons, part of the brain stem. It is most often found in children. Most tumors called DIPG are now called diffuse midline glioma, H3 K27-altered: A change in a histone. A histone is a protein DNA wraps around. A diffuse glioma can have it. If it also sits in the middle of the brain or spine, it is called a diffuse midline glioma. See the glossary, and are grade 4. Surgery cannot safely remove it. Radiation is the main treatment. Ask about clinical trials at the start, without holding up radiation your team says is urgent, and ask about a palliative care: Care that helps with pain and other symptoms. It supports the whole family too. It can start early. It includes help with making choices about treatment. See the glossary team too.

What is DIPG?

DIPG stands for diffuse intrinsic pontine glioma: A tumor that starts in the glial cells. Those are the support cells of the brain and spinal cord. Gliomas are given a grade from 1 to 4. The grade says how the tumor is expected to act. See the glossary. It is a tumor in the pons, which is part of the brain stem.

Diffuse means it grows out into the healthy tissue around it, like fingers, rather than sitting in one lump. That is why surgery cannot take it out.

It is most often found in children, and it is rare in adults.

Not every tumor in the brain stem is a DIPG. Some are low-grade tumors with a different name, and a different plan.

DIPG and diffuse midline glioma

DIPG is an older name that says where the tumor is. Most tumors called DIPG are now called diffuse midline glioma, H3 K27-altered, a name that says what it is. A diffuse midline glioma can also grow in other places, such as the thalamus: A part deep in the brain, near its center. It passes messages from the senses and the body on to the rest of the brain. See the glossary or the spinal cord, and those are not DIPG.

Diffuse midline glioma covers the name, the gene change and the grade.

Is it cancer? What does its grade mean?

Yes. DIPG is cancer. The word your team will use is malignant.

A DIPG with the H3 K27 change is grade 4, which is the top of the scale.

With today's treatments, DIPG is not curable. That is a hard sentence, and it is here on purpose, because hearing the grade without hearing this can leave people shocked later.

Not curable is not the same as untreatable, and it is not a timeline. Treatment can ease symptoms and slow the tumor for a time, and there are still choices if it grows.

You may read that a DIPG can look low grade. That is about how the cells look. For a DIPG with the H3 K27 change, it does not change the grade. Diffuse midline glioma explains why.

Where does it grow, and why does it cause these symptoms?

The brain map with the stalk at the base shaded.
The shaded part is the stalk the brain sits on. Image: Made for BrainHarbor. CC0 1.0 (public domain).

It grows in the pons, in the brain stem, the stalk the brain sits on. The nerve paths for eye movement, hearing, speech, swallowing and balance pass through it. So do the paths for movement in your arms and legs. It also helps control things the body cannot do without, such as breathing and heartbeat.

So a tumor there shows up in the eyes, the face, swallowing, speech and balance. As the pons swells, it can also stop fluid draining from around the brain. The section below explains what that does.

Most people are told what they have long before anyone explains what it is doing. These are the ways a tumor in the brain causes symptoms. They overlap, and most people have more than one going on at once. Which of them apply to you depends on what your tumor is and where it sits.

It takes up room. The skull is a closed box. It cannot stretch. So anything new inside it has to push on something. The tumor and any swelling around it together take up space and press on nearby parts of the brain.

It can make the brain around it swell. This one surprises people, and it is worth understanding. Fluid builds up in the brain tissue near the tumor. That swelling plays a major part in deciding what symptoms you get. Some of what you are feeling may not be the tumor itself. It may be the swelling around it. That is why medicines that bring swelling down can change how somebody feels, without the tumor being any different than it was.

Pressure can build up inside the head. When the pressure inside the skull rises, there is a pattern doctors watch for: headaches that are worse in the morning, feeling sick to your stomach and throwing up, odd eye movements, seizures, and being confused or very drowsy. Not everybody with raised pressure has all of it, and some people have almost none of it. If this pattern is new for you, it is worth a phone call rather than a wait. If you have a shunt, it means getting help right away.

It can set off seizures. A tumor and the irritated brain around it can upset the normal electrical activity of that part of the brain. For some people a seizure is the first sign that anything is wrong.

It can block the flow of fluid. The brain makes a fluid that circulates around it and drains away. A tumor sitting in the wrong place can block that flow, so the fluid backs up and the pressure goes up. This is more likely with tumors near the narrow channels the fluid passes through. It can be treated, and the usual treatment is a shunt. That is a thin tube that carries the fluid to another part of the body, where it is absorbed. It is the word your team will use. Shunts and hydrocephalus covers what having one is like, and the signs it has stopped working.

Why your symptoms are the ones you have

The short rule: the symptom tells you where, the scan tells you what. A tumor disturbs whatever job the brain does in that spot, so where it sits decides what you notice.

There is one exception, and it is the fluid. When the flow is blocked, what you notice is the pressure rather than the spot: headaches worse in the morning, throwing up, double vision, and feeling unsteady. Those signs are much the same wherever the blockage sits, so they tell you the pressure is up, not where the tumor is. If that is your pattern, the part above called It can block the flow of fluid is the one about you, and it says what can be done. If the pattern is new, the phone call above applies.

If something on this list matches what you have noticed, it is worth writing down and taking to your next appointment. Your team can tell you whether it fits where your tumor actually is.

This list is about what the place explains. The other half of the question is what the place changes: whether an operation is offered, how much of it can come out, and when the place makes something urgent on its own. Where your tumor is, and what that changes is that half.

What symptoms does it cause?

Symptoms usually come on fast, often over about a month.

The commonest are:

When to call for help right now

Some things should not wait for the next appointment.

Call an ambulance for any of these. Call 911, or your local emergency number:

A seizure like the ones you usually have, that stops on its own, is not an ambulance call. What to do during a seizure draws the line.

Call your team the same day for any of these:

If you are having chemotherapy, a fever is its own rule. It means calling your team right away, at any hour, not waiting for the morning. An infection during chemotherapy can get dangerous fast, and it is treatable when it is caught early. The fever rule explains why, and what number your team will give you.

In the weeks after brain surgery, a fever is its own rule too, especially with a stiff neck or a bad headache. What comes after a craniotomy has the rest of that list.

If you have a shunt, the signs it has stopped working are their own rule. For you, everything on the same-day list above is a right-away call instead, and so are a few other signs. Get help right away, at any hour: call your team, or go to the emergency department. Signs a shunt is not working has the full list.

If you are not sure whether to call, call. Nobody on that team minds a phone call that turns out to be nothing.

Same day means today, not the next clinic appointment. Ask your team now for the after-hours number, and put it somewhere you will find it at two in the morning rather than somewhere sensible.

What to do during a seizure has the step-by-step, and getting help now is the short version to keep on a phone.

How do doctors find out it is this?

An MRI scan is the main test. DIPG often has a picture on the scan that doctors recognize, and it can be diagnosed from the scan and the symptoms alone.

Whether to do a biopsy is a real choice, and centers differ.

It is fair to ask your team how they weigh it for your child. How tissue is taken explains the stereotactic biopsy: Taking a small sample through a narrow opening in the skull, guided by a scan. A full opening is not made. It is used when the area to be sampled is hard or risky to reach. See the glossary itself, and the H3 K27 result explains the test.

What do the words on my report mean?

The rules for naming brain tumors changed in 2021. If your paperwork was written before that, some of its words are no longer used.

This matters more than it sounds. People read an old report next to a new one, see two different names, and think somebody made a mistake. Usually nobody did. The tumor did not change. The way doctors write it down changed.

Three changes affect almost every report.

Seeing an older name on your own report does not mean it was wrong. It means it was written under the old rules. If you are holding an old report and a new one and they do not match, that is a good thing to take to your team and ask about.

If there was no biopsy, the diagnosis comes from the MRI report, and there is no gene result on paper.

If your older paperwork says something different

How is it usually treated?

A tumor board is a meeting where specialists look at one person's case together: surgeons, cancer doctors, the lab, and the people who read scans. It tends to happen when a case is complicated or something is hard to read.

You do not go to the meeting. Afterwards, the doctor who knows you best explains what was said.

What they decide is advice, not an order. The choice is still yours. Because you are not in the room, tell your team what matters to you before it happens, so it is taken into account.

One hard thing to know before radiation starts. Radiation usually eases symptoms for a time, and the tumor often shrinks for a while. It is not a cure. Ask your team what radiation is meant to do for your child.

In general, chemotherapy is not part of standard care for DIPG. Diffuse midline glioma has the honest note about it.

Dordaviprone, and one thing to know for a tumor in the pons

Dordaviprone is a capsule taken once a week. It is approved for a diffuse midline glioma with the H3 K27M change that has kept growing after other treatment.

It was given accelerated approval. That means it was approved early, based on how many tumors shrank and for how long. Trials are still checking whether it helps people live longer. Until they report, nobody can tell you that it does.

The studies the FDA used to judge whether it shrinks tumors left out DIPG. Most of the people in them were adults. The approval itself does not exclude DIPG, and the American Cancer Society says it may be an option for a DIPG that grows after radiation. So the evidence that it shrinks tumors comes from other tumors, mostly in adults. Ask your team what they know about it for your child's tumor, and whether your child has the gene result it needs.

Clinical trials, and why to ask early

Many children with DIPG get their care through a clinical trial. There are trials that start at diagnosis, after radiation, and after the tumor grows. Asking at the start keeps the most options open, as long as it does not hold up radiation your team says is urgent. Clinical trials explains how they work.

What is treatment actually like, and what is normal afterwards?

Radiation for a young child. A young child who cannot lie still may be given medicine to sleep through each session. This is called anesthesia. At some centers, parents can see and talk to their child on a screen from outside the room. Some centers let a child who is close to managing without it practice lying still in the empty room first. Ask what your center does. What radiation is like covers the rest.

Steroids change how your child looks. Weight gain and a round, puffy face come mainly from the medicine, not from the tumor. Steroids goes through the rest of what they do.

The better stretch after radiation. For many children the tumor shrinks for a while after radiation. Symptoms ease, and they can go home to their usual things. Some families hear this called the honeymoon period. It is hard to predict. Some children are almost back to how they were, and some do not improve at all. Neither says anything about how hard anybody tried.

If symptoms that had eased start to come back, call your team the same day, or right away if there is a shunt. Anything on the ambulance list is still an ambulance call.

Palliative care is worth meeting early. The word can sound like giving up. It is not. The team is meant to be there from the start.

Everyday life: school, seizures and tiredness

Follow-up scans, and what to do while you wait

Scans continue after radiation. Follow-up scans goes through what they are compared with, and waiting for results covers the gap before the answer.

If it comes back, or changes

If the tumor grows again, there are still choices. Your team may talk about a clinical trial, dordaviprone, radiation again, or care that focuses only on comfort.

Radiation a second time is something doctors disagree about. St. Jude says it can be done safely, but the tumor is harder to treat the second time and the benefit is more limited. It is usually given over two to three weeks. A 2022 review of DIPG says it can help slow the tumor, but it has significant risks and burdens, and is not usually recommended. Ask your team whether it is an option, and what it would be for.

No choice here is the wrong one. Ask your team what each option is for, and write the answers down.

Did I cause this?

Almost everybody asks this, usually in the first week, usually in private. It is worth answering plainly.

For most brain tumors, nobody knows the cause. That is the honest state of it. The exact cause of most brain and spinal cord tumors is not fully understood, and there are very few well established risk factors. Tumors start when genes that control how cells grow and divide are changed, and in most cases those changes happen by chance during a person's life. Not because of something done or not done.

Cell phones. They give off a kind of radiation called radiofrequency. It is not the same as the radiation in an x-ray. The energy is too low to damage DNA, and it is not known to cause cancer. The evidence so far is that using a cell phone does not cause brain tumors.

Stress. There is no scientific evidence that stress causes brain tumors, and no data linking stress to a higher chance of getting one. A hard year before a diagnosis is a hard year. It is not a cause.

Something you ate, or did not eat. No food and no diet is an established cause of a brain tumor. It is not on the list of known risk factors at all.

Something you passed on, or caught. Brain tumors are not contagious. Most are not inherited either. A small number of people do have an inherited condition that raises the risk, and if that applies to you, your team will raise it and offer to talk it through.

If you are turning this over at three in the morning, that is ordinary and it happens to nearly everyone. It is also worth saying out loud to somebody on your team, because they have answered it many times and they would rather you asked.

Will my other children get this? This tumor is not passed down in families. It is nobody's fault, and nothing done in pregnancy or early childhood has been shown to cause it.

What might happen over time

The next part is about outlook. Some people want to read it. Some people would rather not. You can skip it and come back another day. Nothing else on this page depends on it.

Show the part about outlookHide the part about outlook

Doctors sometimes describe outlook using numbers. It helps to know what those numbers are before you decide whether you want them.

Those numbers describe children who were treated years ago. For a long time a biopsy was not usually done, so many older studies counted tumors by how they looked on a scan, before the gene test. An older figure may describe a mixed group.

The word you will run into is median. A median is the middle of a group. If you lined everybody up, the median is the person standing in the middle. It is not a prediction about any one person.

The shape of the group matters as much as the middle. A few children live well beyond it. St. Jude says that is usually linked to unusual features of the tumor, or to a tumor that turned out not to be DIPG. It also says very young children, and children who had symptoms for longer before diagnosis, may do a little better. A median cannot show you any of that.

In the better stretch after radiation, families may use the time to be together, or to do something special. Wish-granting organizations can often help with that.

Care near the end of life is something families are encouraged to talk about early, with the palliative care team, while there is time to think. Hospice care can happen at home, which is sometimes where a child would rather be, and it can start while a child is still having treatment. Pediatric hospice keeps supporting the family after a child dies, too. Ask your team who to talk to, and when.

For the person caring for someone with this

If you are the one driving to the appointments, keeping track of the pills, and lying awake at night worrying about them, this part is for you.

You are allowed to ask questions. In one study, families said they were afraid of annoying the doctor by asking too much. One of them was told by a doctor to stop playing doctor. Ask anyway. Write your questions down before you go, and bring a notepad. Two people in the room hear more than one.

Ask who your first call is. Care comes from a lot of people at once, and it is easy to end up as the only one holding it together. Ask the team: who do I call first? Some teams have one person whose job this is, often a nurse. Get the name and the number.

Get two numbers, and know which one to use. One for work hours, one for nights and weekends. Then ask what counts as "call us today" and what counts as "call an ambulance" for this tumor, and write the answer down where you can see it. If you are not sure which it is, call. Nobody on that team will mind.

If they have seizures, read about them before you need to. What to do when someone has a seizure is the one to know by heart. Living with seizures is about the rest of the time: what is safe, what to change, and driving.

Ask to be shown anything you are sent home to do. In that same study, families were sent home to change dressings and give medicines with no training at all. That is not fair to you. Before you leave the hospital, ask someone to show you. Then do it once while they watch.

Say what you notice. You may see a change before they do. Changes in thinking, mood and behavior can show up to the people close by first. Telling the team is not going behind their back. It is something the team cannot learn any other way.

Look after yourself, and let people help. Eat, sleep, and keep your own appointments. Take a little of the day back for yourself. When someone asks what they can do, give them a real job: a meal, a ride, an hour with the kids. Most people want to help and do not know how to offer.

You can talk to somebody about all of this today. See where to get help.

Two things specific to this diagnosis.

You are most likely a parent. Everything above still applies to you, and so does asking early for the palliative care team. That team is there for the whole family, not only the child with the tumor.

Watch swallowing. New trouble swallowing, or new drooling, means calling your team the same day. Food or drink can go down into the lungs. Choking, or trouble breathing, is an ambulance call.

What to ask your team

Where to get support

This is not medical advice. It explains research in plain words. Your care team knows your case. Talk with them before you make any decision about your treatment.

Last reviewed: September 15, 2026

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