Astrocytoma

Three different groups of tumors share the name astrocytoma. Which one of the three is yours. What the gene results on your report mean. And both directions of the glioblastoma rename.

The short version

Three different groups of tumors share the name astrocytoma, and they are not variations of one thing. One group includes a tumor surgery can cure. Another cannot be cured, and is treated over years. Which one you have is set by your grade and your gene results, both of which are on your pathology report. This page helps you work out which one is yours. It also covers the name changes that land here more than anywhere else, including the one that moved a whole group of tumors out from under the name glioblastoma: A glioma that is given grade 4. Grade 4 is the highest grade there is. The tumor grows fast. Treatment usually starts soon after it is found. It often means surgery, and then radiation and chemotherapy. See the glossary.

What is an astrocytoma?

Your brain has nerve cells and helper cells packed around them. One kind of helper cell is shaped like a star, and is called an astrocyte. An astrocytoma is a tumor that starts in those cells, or in cells that look like them. It is one kind of glioma.

The three groups, and why the difference matters

So the grade and the gene results tell you more than the word astrocytoma does. If you have been told only the name, the question that gets you further is: is mine IDH-mutant, what grade is it, and does it have a clear edge?

Is an astrocytoma the same thing as a glioblastoma?

They are related, and the honest answer has two halves.

Biologically, a glioblastoma is an astrocytic tumor. The American Cancer Society puts it plainly: glioblastoma is the most common type of astrocytoma.

But since 2021 they are separate diagnoses, and the dividing line is the IDH gene. A tumor with an IDH change is never called glioblastoma now, whatever its grade. A tumor without one may be called glioblastoma even at grade 4 of the same-looking disease. So if your report says astrocytoma, IDH-mutant, grade 4, you do not have a glioblastoma. Research written about glioblastoma is not written about you.

Is it cancer? What does its grade mean?

Some are and some are not, and your grade is what decides it. Grade 1 astrocytomas with a clear edge are usually called benign. Grade 2 and above IDH-mutant astrocytomas are cancer.

The word for the ones that are cancer is malignant. The word for the ones that are not is benign. Benign in the brain does not mean harmless. A benign tumor still takes up room inside a closed skull, and it can still press on a part of the brain that matters.

Grade 1 astrocytomas usually sit in a lump with an edge. Pilocytic astrocytoma is the usual example. If a surgeon can safely reach all of it, an operation can genuinely be the end of it. For those, "they got it all" can mean finished.

Grade 2 and above IDH-mutant astrocytomas are different. They grow out into the brain around them, so there is no edge to cut around. They are malignant, and with today's treatments they are not curable. That is a hard sentence and it is here on purpose. Being told "low grade" and hearing "not serious" is the commonest mistake people make about these tumors. It falls apart later, at the worst possible time.

Not curable is not the same as untreatable, and it is not a timeline. Treatment can work for a long time, and some of these tumors are watched rather than treated for years. What it means is that the plan assumes the tumor will need attention again, which is why the scans do not stop.

What the grade actually describes

A grade describes how abnormal the cells look under a microscope, and what the gene tests say. For an IDH-mutant astrocytoma there are three:

That last one trips people up. A tumor can be graded 4 on the gene result alone, even when the cells did not look that way. It is not a mistake and nobody was hiding anything. The gene results took longer to come back than the first impression did, and they carry more weight. The words on your gene results takes CDKN2A/B and the rest one at a time.

Grading is also done inside each tumor type since 2021, so a grade 4 astrocytoma and a grade 4 of some other tumor do not describe the same thing. Comparing your grade with somebody else's, when the names differ, tells you less than it looks like it does.

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

A side view of the brain with each part labeled in plain words.
The parts of the brain, in the words this site uses. Image: Made for BrainHarbor. CC0 1.0 (public domain).

An IDH-mutant astrocytoma can occur anywhere in the brain or spinal cord, but it is usually near or in the frontal lobes, the front of the brain. That matters more than a location usually does, and the next section is about why.

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.

The change that came before the diagnosis

Tumors at the front of the brain are the ones linked to changes in behavior and personality. Those changes can come on slowly enough that nobody connects them to illness.

The National Brain Tumor Society puts it plainly: with tumors in the frontal lobe, changes in behavior and personality can be present months to years before diagnosis. Subtle changes in speech, vision or sensation can be there beforehand too.

After a diagnosis, families often look back and see it. Months or years of someone being short-tempered, withdrawn, flat, or just not themselves. Seeing that can bring a lot of guilt with it, on all sides.

So it is worth saying directly:

If this is still going on, say so at appointments. Some of it can be helped, and some of what looks like the tumor turns out to be the steroids or the seizure medicine instead.

What symptoms does it cause?

Seizures are common at diagnosis. Alongside them: headaches, trouble finding words, trouble understanding speech, changes in vision, and weakness or numbness on one side. So are the changes in behavior and thinking described above.

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?

A scan first, then a piece of the tumor.

How tissue is taken goes through both ways of getting that sample.

The answer arrives in layers rather than all at once, and the name can change as later results come back, which on this page is not a small thing. Waiting for results is about that wait.

What do the words on my report mean?

Four results do most of the work on an astrocytoma report.

Each has its own entry on the words on your gene results. Your pathology report, part by part walks through the document itself.

If your paperwork uses words you cannot find

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.

The renames that land on this page, and they run both ways

More retired names point here than to any other page, and one direction is reassuring and the other is not. Both are below, because finding out the hard one by accident is worse.

If your old report said glioblastoma with an IDH change, you are in the right place. That tumor is now called astrocytoma, IDH-mutant, grade 4. Nothing about it changed. It was moved out from under the glioblastoma name. These tumors were found to behave differently from the ones still called glioblastoma. You have not been given a different disease, and you have not been downgraded or upgraded. It was renamed.

You may also see the older phrase secondary glioblastoma. It meant a glioblastoma that had grown out of a lower-grade tumor, so it described how the tumor arose rather than what its genes said. Which page is yours comes down to the IDH line on your report. IDH-mutant means this page. IDH-wildtype means glioblastoma. If your old paperwork uses that phrase and you cannot find an IDH result anywhere, that is a good thing to ask about.

And here is the direction nobody warns people about. If your tumor is IDH- wildtype, meaning it does not carry an IDH change, the 2021 rules may call it a glioblastoma, grade 4, on gene results alone. That happens when the tumor has certain changes: a gain of chromosome 7 with a loss of chromosome 10, extra copies of a gene called EGFR, or a change in the switch that turns on a gene called TERT promoter mutation: A change in the switch that controls the TERT gene. It keeps tumor cells from aging out. It is one of several findings your team reads together to name the tumor. See the glossary. It happens even when the cells did not look grade 4 under the microscope.

So some people whose report once said "anaplastic astrocytoma" are now told they have a glioblastoma. That is a real change in what you are called, and it is fair to be shaken by it. It is not a new tumor and it is not something that was missed. It is the same tissue, read against rules that now weigh the gene results more heavily. If this is you, glioblastoma is the page you want, and the question to ask your team is: is mine IDH-mutant or IDH-wildtype, and which name applies to me now?

How is it usually treated?

The plan depends on your grade, your gene results, where the tumor sits, and how much of it can safely be removed.

Alongside these there is supportive treatment: medicine to bring swelling down, medicine to control seizures if you have had one, and help with tiredness.

Clinical trials are a normal part of this conversation, at diagnosis and again later.

Why the grades are treated differently

These three are for the IDH-mutant group. A circumscribed tumor of the same grade is treated differently, so ask which applies to you.

If your plan looks different from someone else's with the same grade, the question that gets you the answer is: which exact diagnosis is mine, and why this plan for it?

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.

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

The library pages go through the day-to-day of each one. What the operation involves, and the weeks after it. What a course of radiation is like from the inside. What chemotherapy does to your blood counts.

Two things particular to this group.

Finishing treatment is not the same as feeling finished. Tiredness after radiation often arrives late and lingers. Thinking and memory can feel slower for a while. Neither means treatment failed.

"Is this the tumor, or the medicine?" matters more here than on most pages, because the front of the brain is already involved. Steroids cause muscle weakness and can change mood. Seizure medicines can affect temper and concentration. If someone seems more irritable after treatment starts, that is worth asking about rather than assuming the worst. Steroids covers what that medicine does and what can be done about it.

Everyday life: work, driving, seizures and tiredness

Seizures and driving. The rules depend entirely on where you live, and in some places it is your doctor who has to report it rather than you. Living with seizures covers the practical side, and the driving section is where to start before confirming it with your own team.

Work and money. Many people keep working, sometimes with changes. Where the front of the brain is involved, the difficulty is often not the tasks themselves but planning, starting things, and holding on to attention. Those are worth naming at work rather than pushing through, because adjustments exist for them.

Relationships. This is the one people do not expect. Changes in temper, motivation and warmth are hard on the people closest to you, and they often started before anyone had an explanation. Saying out loud that some of it was the tumor can matter a great deal to both sides.

Tiredness and thinking. Both are common and both are easy to blame on the wrong thing. Say them out loud to your team. There are things that help, and nobody offers them if they do not know.

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

Scans continue whether or not you are having treatment, and for some people they are the plan.

The wait has a name: scanxiety. For most people the hardest part is not the scan but the gap between the scan and the result. Ask who will give you the result and roughly when, and ask one more thing: will it appear in your online records before anybody calls you? For a lot of people it does.

If something changes between appointments, you do not have to wait. Bringing a scan forward is an ordinary thing to ask for.

Follow-up scans, and what the results mean goes through what your team compares your scan with, and what the words on the report mean.

If it comes back, or changes

Some grade 2 astrocytomas change into a higher grade over time. That is called transformation, and it can go to grade 3 or straight to grade 4. It is a known behavior of these tumors rather than a sign something went wrong, and it is one of the things each scan is looking for. If it happens, the treatment options are the ones on this page, in a different order.

For grade 3 and grade 4, the plan assumes the tumor will need attention again from the start. That is why the scans continue.

If something does change, there are usually still options. More surgery. Radiation, if it has not been used or can be used again. A different drug. A clinical trial. Which of them are open to you depends on your diagnosis, what you have had already, and how well you feel day to day.

Being told there has been a change is a hard day. It is not the same as being told there is nothing left to try.

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.

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 is worth knowing what those numbers are before deciding whether you want them.

They come from large groups of people treated years ago, and that matters more here than on most pages. The 2021 rules moved a whole set of tumors out of the glioblastoma group and into this one. So an older figure may describe a group that included people who would be given a different diagnosis today, or exclude people who would now be given yours.

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. Half did better and half did worse. It is not a prediction about any one person, and it is not a number of months anybody was handed.

The other thing worth knowing is the shape of the group. These figures are not spread evenly around the middle. There is a long tail of people who do far better than the middle, and those are real people rather than exceptions to be set aside. A median cannot show you that tail, which is one of the reasons it is a poor thing to hear on its own.

What shapes your own situation most is your exact diagnosis, your grade, your gene results, how much of the tumor came out, and how it behaves over the first few years. Those are things your own team can see, and a page written for everybody cannot.

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.

This page has a section most tumor pages do not need, and it is for you. If the tumor is at the front of the brain, the changes you have been living with may go back months or years. A shorter temper. Less interest in things. Less warmth. Plans not made, or not kept. You may have spent that time thinking the relationship was in trouble, or that you were failing at it.

You were not. Some of what you were dealing with was, in some part, a tumor in the part of the brain that shapes personality. Knowing that afterwards is its own kind of hard, and it is worth saying to somebody rather than carrying it quietly.

What helps, practically:

If seizures are part of this, learn what to do before you need to. What to do during a seizure is the one to know.

Look after your own health, and keep your own appointments.

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 8, 2026

Sources for this page:

Some parts of this page are shared with other pages on this site. These are the sources for those shared parts. They are here so you can check any part of this page.