Meningioma: what it is, where it sits, and why size is not the headline

A meningioma starts on the covering of the brain rather than inside it. And there is often a visible gap on the scan that shows the difference. What the grade means, and why location matters more than size. What the words on your report mean. And the hormone medicines worth asking about.

The short version

A meningioma starts in the layers that wrap your brain, not in the brain itself. That is a real difference, not a form of words. On many scans you can see a strip of fluid between the tumor and the brain. That strip is what tells a radiologistradiologist: A doctor trained to read scans and write down what they show. The report goes to the doctor who asked for the scan, who then tells you. One who specializes in the brain and spine is called a neuroradiologist. See the glossary it sits outside. Most meningiomas are grade 1 and grow slowly, and a lot of them turn up by chance on a scan taken for another reason. What matters most is not how big it is. It is where it sits and what it is pressing on. A small one with a nerve right beside it can matter more than a larger one with room around it. And if you take any hormone medicine, that is worth raising early, because a few of them matter here.

What is a meningioma?

It is a tumor that grows from the coverings of the brain.

Your brain and spinal cord are wrapped in three thin layers called the meninges. They cushion the brain, carry its blood vessels, and hold the fluid that flows around it. A meningioma grows from cells in the middle of those three layers.

So it is next to your brain rather than in it. Doctors have a word for that: extra-axialextra-axial: Growing outside the brain itself, not inside it. A meningioma is one. It starts in the layers around the brain and presses inward. See the glossary, meaning outside the brain substance. It is the most common tumor of that kind.

And a scan can often show it. On a scan, a rim of the fluid that normally flows around the brain can often be seen between the tumor and the brain surface. Radiologists look for that strip on purpose, because a tumor growing inside the brain cannot have it. If your report mentions it, that is what it is telling you.

The honest limit of that

This is the part most pages leave out. Leaving it out is how "it is not in your brain" turns into "it is harmless".

A meningioma grows inward and presses. Pressing causes real symptoms and real damage. Where it grows around a nerve or a large vein, it can be genuinely difficult to remove. Some of them are graded 2 or 3 and grow faster.

So: starting outside the brain matters, and what it matters for is what the tumor is doing to brain tissue. It does not settle everything else, and this page tries to hold both.

Is it cancer? What does its grade mean?

Most meningiomas are not cancer, and the word "benign" does more harm than good here.

Grades run 1 to 3, and they describe how the cells look and behave under a microscope. They are written as ordinary numbers now. A grade is not a prediction about you.

• Grade 1 is most of them. Slow-growing.
• Grade 2, sometimes written "atypical", is a smaller number. It comes back more often, which changes the plan rather than the diagnosis.
• Grade 3 is a small number. It grows faster and is treated more firmly from the start.

We do not print what share falls into each grade. The counts that exist do not agree with one another, and the number would only be used to guess at your own situation.

Two things can change a grade without anything looking different under the microscope. One is a change in something called the TERTTERT 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 promoter. The other is losing both copies of CDKN2A or CDKN2B, which are two different genes. Either of those two changes makes it grade 3, whatever the cells look like. What the markers mean explains those words.

Why "benign" is a poor word for this. It means "not cancer", and people hear "harmless". A grade 1 meningioma can still take your sight. A grade 1 meningioma can come back years later. Both of those are true of something that is not cancer. The useful questions are where it is and what it is doing, not which side of that word it falls on.

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

This is the idea the whole page is built on. Where it sits decides what you notice, and much of what your team plans. Size decides less than you think.

A meningioma can grow anywhere the coverings go, and the coverings go everywhere your brain and spinal cord do. What it presses on is what you notice. So two people with the same size tumor can have completely different lives.

Your report probably names the address, not just the tumor. Meningiomas are usually called after the spot they grew from, so a letter may say "convexity meningioma" rather than just "meningioma". The list below holds the addresses themselves, in plain words first, with the word your report is likely to use.

What a tumor in different parts of the brain tends to do comes later on. That list reads the same whatever kind of tumor is sitting there. So each entry here adds only what that list cannot say about a meningioma at that address.

• On the surface, under the top of the skull. Often nothing at all for a long time. Which part of the brain it sits over decides the rest. Your report may call this a convexity meningioma.
• In the covering that runs between the two halves of the brain. Weakness in a leg is the give-away here. Your report may call this parasagittal, or name the covering itself, the falx.
• On the wing of bone behind the eye socket. Loss of vision, double vision, numbness in the face, or an eye that slowly starts to bulge. Your report may call this a sphenoid wing meningioma.
• On the floor at the front of the skull, by the smelling nerves. Loss of smell that often goes unnoticed for years. Your report may call this an olfactory groove meningioma.
• Near the pituitary and the crossing of the optic nerves. It grows beside the pituitary gland rather than out of it, so a pituitary tumor is a different thing. Your report may call this tuberculum sellae.
• At the back, near the brainstem and the nerves to the face and ear. Facial pain, or a hoarse voice. Your report may call this the posterior fossaposterior fossa: The space low at the back of the skull. It holds the cerebellum, which helps with balance, and the brain stem. See the glossary, or petroclival.
• Inside the fluid spaces of the brain. Your report may call this intraventricular. When where it sits makes it urgent is the part to read if this is yours.
• On the spinal cord. Back pain that is typically worse at night, numbness, and weakness in the legs. The general list further down is about the brain, so this address is not on it.

"Skull base" is an umbrella word you are likely to meet. It covers more places than this page names. Some of the addresses above sit under it, such as the one on the floor at the front and the one near the brainstem. Yours may sit under it even if it is not named here. Ask your team whether yours counts. The floor of the skull is where the word itself is explained.

The point, said plainly. The measurement on your report is not the headline. What the tumor is up against is the headline.

What the address changes about the plan

Nobody can read your outcome off the address. There is no list here of good spots and bad ones. What the address changes is what your team is aiming at, and that is a thing you can ask about.

Why your team keeps coming back to where it sits sets out the things that decide how much of a tumor can come out. The guideline quoted there is the European one for meningioma, so that list is yours rather than a general one. Your address is one of the things on it.

What is next to a tumor changes what the team protects. On the floor of the skull, the nerves that serve the face, eyes and ears run through. Keeping those working is a major concern there. So a planned smaller operation, followed by focused radiation, is used more and more. Around the optic nerves, that radiation has been used in a few smaller sittings rather than one, for the same reason. That trade is about what is touching your tumor, not about the address. It comes up wherever the tumor is right up against something a surgeon will not risk. The floor of the skull and the optic nerves are named here because the guideline names them, and neither is a place being ranked. Both of those plans are your team saying out loud what they are protecting.

Taking out less, on purpose, can be the plan rather than a disappointment. Where the whole tumor cannot safely come out, the guideline's advice is to plan the smaller operation rather than push on. That is sometimes decided beforehand and sometimes in the room. What happens in an operation on the brain goes through the words your report will use afterwards.

On the spinal cord the question is a different one. There an operation is usually what is offered. What your team weighs is whether to operate or to watch instead. They weigh the good that taking it out would do against the risk of the operation itself. Spinal cord tumors covers that decision and the operation behind it.

And "where is it, and what does that change?" is a question you can ask in those words. Where your tumor is, and what that changes is the page for the address on its own, whatever the word on your report turns out to be.

And why does that cause symptoms at all?

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.

• Front of the brain. Personality, behavior, planning, motivation, and on one side, producing speech.
• Side of the brain, near the temple. Seizures, memory, and understanding what people say.
• Upper back part of the brain. Sensation, knowing where your body is in space, reading, writing and arithmetic.
• Back of the brain. Vision, and losing part of your field of view.
• Cerebellum, low at the back. Balance, coordination and walking.
• Brainstem. Double vision, facial weakness, and trouble swallowing.
• Deep in the middle, near the spaces the fluid runs through. A tumor here can block the flow, so what you notice is often the pressure rising rather than anything that points to the spot.
• The floor of the skull, below and behind the ear. Hearing, balance, and the nerves to the face. So hearing loss or ringing in one ear, dizziness, and numbness or weakness down one side of the face. Your team may call the whole floor of the skull the skull base. This spot is one part of it.
• Behind the eyes, at the base of the brain. Vision, and the hormones that set energy, weight, thirst and periods. In a child, growth and puberty too. Side vision is what usually goes first, so things start disappearing at the edge. Your team may call this the pituitary or the sellar region.

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?

It depends on where it sits, so the addresses and the general list above are where to look. The ones that turn up across many locations are headache and seizures, something going wrong with your eyesight, and a limb that feels weak or numb. Then there are the changes in thinking, mood or personality, which the people around you often spot before you do.

Many meningiomas cause no symptoms at all.

If your meningioma is on your spinal cord, the list below is not yours. The signs that matter there are different, and they are the ones doctors call red flags: new weakness in the legs, a change in how you walk, numbness around the saddle area, and any new trouble with your bladder or bowel. New weakness or a change in how you walk is a same-day call, not something to leave until the next appointment. Do not wait for it to get bad first, because the early signs are often vague ones. New trouble controlling your bladder or bowel, or numbness around the area you would sit on, is the emergency room now rather than an appointment. Spinal cord tumors is the page for that half.

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 first ever seizure.
• A seizure that lasts more than five minutes.
• One seizure right after another, with no waking up in between.
• Someone who cannot be woken.
• Trouble breathing, or someone who seems to be choking.
• Suddenly not being able to speak, move one side, or see.

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:

• A headache much worse than usual, or one that wakes you from sleep.
• Throwing up again and again.
• New weakness in the face, an arm or a leg.
• New trouble speaking, or understanding what people say.
• New confusion.
• Sleeping much more than being awake.
• A sudden change in your vision.

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?

Usually with a scan, and often before anybody suspected anything.

A meningioma has a look an MRI can often pick out. A lump with a clear edge, attached to the covering. It lights up evenly with contrast dyecontrast dye: A liquid put into a vein before some scans. It makes certain tissues stand out, which helps show where a tumor is. It does not always show the whole of it. See the glossary. And that strip of fluid sits between it and the brain. A CT can show thickened bone next to it, or flecks of calcium inside it. MRI scans covers what the scan itself is like.

Many are found by accident. Somebody is scanned after a car accident, or for headaches, or for dizziness, and there it is. That is not bad luck uncovering a hidden disaster. Meningiomas are common enough that a meaningful number of people are walking around with one they will never know about, and scanning a lot of people finds them.

Here is the gap almost nothing tells you: if you have not had surgery, your grade is an estimate. Grade comes from looking at cells, and that needs tissue. Before an operation, a team can say how it looks and how it behaves, and that is genuinely informative, but it is not the same as a grade off a report. If somebody has told you a grade and you have not had surgery, it is fair to ask which of those two you are being given. Biopsy and the pathology report cover the tissue side.

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.

• Roman numeral grades, such as grade II or grade IV on an older report. These are now written with ordinary numbers instead: grade 2, grade 4. Nothing about the grade itself changed. Only the way of writing it did.
• Gene results are now part of the name. Older reports named a tumor mostly by how the cells looked. A name written now usually has a gene result built into it. That is why a newer report can look longer and more technical than an older one about the same tumor. You may also see NOSNOS: Short for "not otherwise specified". It means the gene tests needed to name the tumor fully were not done or could not be done. Ask your team whether they can be. See the glossary or NECNEC: Short for "not elsewhere classified". The tests were done, but the results do not match any named tumor type. Ask your team what it means for your plan. See the glossary written next to your diagnosis. These say something about the testing, not about how serious the tumor is. NOS means the tests needed to be more exact were not available. NEC means testing was done, but the results did not fit any defined group neatly.

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.

Meningioma reports are unusually full of jargon, and some of it sounds much worse than it is.

Extra-axial. Outside the brain substance. This is the reassuring one.

CSF cleft. The strip of fluid between the tumor and the brain described above. It is evidence the tumor sits outside.

Dural taildural tail: A streak of thickened covering next to the tumor on a scan. It is a common sign on a meningioma scan. Other things can cause it too. See the glossary. A thin tapering streak of the covering next to the tumor, lighting up with dye. Common with meningioma, but it turns up with other things too, so on its own it does not settle anything.

Hyperostosis. Thickening of the bone beside the tumor.

Calcificationcalcification: Calcium built up inside a tumor. It shows as bright specks on a CT scan. It is common in oligodendroglioma, and the pattern can point to that diagnosis. It is not something you did. See the glossary. Flecks of calcium in the tumor, seen best on a CT.

Brain invasion. This is the one that frightens people, and it does not mean what it sounds like. It has a strict definition: tumor cells have to break through the innermost covering layer and push into brain tissue in finger-shaped tongues. Indenting the brain is not invasion. Nor is growing along the outside of a blood vessel as it dips into the brain, because that innermost layer stays intact. When it is present it moves the tumor to grade 2 on its own. And whether it actually predicts anything is unsettled among the specialists who wrote the rule. Several studies have found no consistent link with the tumor coming back. If those two words are on your report, they mean more testing and a closer plan, not a verdict.

Ki-67Ki-67: A stain that shows how many tumor cells were dividing when the sample was taken. The report gives it as a percentage. It is read together with everything else, not on its own. See the glossary, or MIB-1. A measure of how many cells are dividing. Higher goes with a higher chance of it coming back.

Progesterone receptor. Whether the tumor's cells carry a docking point for that hormone. Many meningiomas do. It connects to the medicine question below.

Grade 1, 2 or 3, and Simpson I to V, which is a completely different thing. Your operative note may carry a Simpson grade in Roman numerals. It is not a second opinion on your WHO gradeCNS WHO grade: A number from 1 to 4 for how a tumor is likely to behave. Since 2021 it is written in plain numbers, not Roman ones. Gene results can set it too. See the glossary. Simpson describes how much came out. I is the whole tumor, plus the piece of covering it grew from, plus any abnormal bone. V is a biopsy, or an operation to relieve pressure only. I, II and III all count as a complete removal. IV means some was deliberately left behind. So a report can say "grade 1, Simpson II", and each number is telling you something different.

One more, if the Roman numerals worry you. The section above explains that Roman numeral grades belong to the old way of writing things down. Simpson grades are the exception, and always have been: they are written in Roman numerals on purpose. So Roman numerals beside the word Simpson are expected. Your WHO grade is the one that should be an ordinary number.

NF2-related schwannomatosis. An inherited condition linked with meningiomas. It used to be called neurofibromatosis type 2. The name was changed in 2022, because the growths the old name described are not the ones that actually occur in it. An older letter will say the old name. Around half the people who have the condition have meningiomas. If this is in your family, ask your team what that means for relatives.

How is it usually treated?

There are three treatments and one honest gap, and which of them applies depends on the tumor rather than on preference.

Watching it. For a small one causing no trouble, a plan of scans is the recommended approach rather than a delay. What triggers a change is growth that keeps going, symptoms starting, or the tumor getting close to something important. A little growth does not automatically change the plan, so ask your team how much change would make them act. Watching a tumor, step by step sets out what living with that plan is like, and it has a section on meningioma specifically.

Surgery. The main treatment for one that is causing symptoms or growing. The aim is to take out the tumor. Where it is safe, the surgeon also takes the piece of covering it grew from, and any abnormal bone. That is what makes it much less likely to grow back. How completely that can be done depends on more than the address, and what the address changes sets out what your team is weighing. Brain surgery covers the operation and the weeks after.

Radiation. Used when a tumor cannot be removed, when some is left behind, or after surgery for grade 2 and grade 3 tumors. It can be given as a focused single treatment or a few, or as a longer course over weeks. Radiation therapy covers what that involves, and the focused single treatment, stereotactic radiosurgerystereotactic radiosurgery: Radiation aimed at a small target, in one visit or a few. There is no cutting, despite the name. See the glossary, has a page of its own. Doses and schedules are your team's to set, and they differ between tumors and between hospitals.

Drug treatment: the honest answer is that there is not one yet. No medicine is approved specifically for meningioma. Several have been tried over the years. If your tumor keeps coming back, that is a reason to ask your team what is being studied, rather than a reason to assume a drug exists. Clinical trials covers how to think about that.

Am I on a medicine that should be looked at?

This is the part of the page with something to actually do in it. Read to the end of the section rather than the middle.

Some hormone medicines are linked with meningioma. Not all of them, and not to the same degree, which is exactly why this needs three answers rather than one.

Strongest, and the one with a clear instruction: high-dose progestogens. A medicine called cyproterone acetate is linked with meningiomas being more common and growing faster, and the advice to doctors treats that as a real risk rather than a maybe. The guidance to doctors is to stop it permanently if somebody is diagnosed with a meningioma. Two related medicines, chlormadinone acetate and nomegestrol acetate, carry a similar but lower risk. There is some evidence the risk falls again after cyproterone acetate is stopped.

Cyproterone acetate is prescribed for several reasons, and one of them is gender-affirming hormone therapy for trans women. It is also used for heavy hair growth and for acne. If you take it for any of those reasons, this applies to you and it is worth raising at your next appointment. It is a conversation about alternatives, and there are alternatives.

Mixed, and with a real trade-off: hormone replacement therapy. HRT around the menopause seems to raise the risk, and the evidence is less settled than for the medicines above. The advice is to avoid it where you can if you have a meningioma or have had one removed. But menopausal symptoms can be worse to live with than the meningioma, and that is a judgment to make with a doctor rather than alone. Do not stop HRT on your own on the strength of a web page.

Other contraceptive pills: no apparent increase, with one exception. Ordinary contraceptive pills do not appear to raise the risk, and here is the exception that matters: some combined pills contain cyproterone acetate, usually prescribed for acne or excess hair. Those belong in the group above. So the useful move is not to reason about your pill. It is to take the box to your team and ask which kind it is.

Fertility treatment. There is not enough information to say either way.

Nothing here means stopping a medicine today by yourself. What it means is putting the list of what you take in front of somebody this month.

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

If you have surgery, the first weeks are mostly tiredness. A deep, unfamiliar tiredness that comes in waves and takes longer than people expect to lift. The scar aches. Concentration is patchy. Sleep is odd.

What you can expect to recover depends on what the tumor was pressing on and for how long. Pressure that has been there a long time does not always undo completely. A nerve that was already thinned may not come all the way back. Ask about that before the operation. What counts as a good outcome for you depends on the answer.

Was the tumor near the nerves for vision, hearing, smell or the muscles of the face? Then ask three things. What is expected to improve. What is expected to stay. And how long anybody will wait before calling it settled.

And here is the thing nobody warns people about. A grade 1 meningioma taken out completely is often the end of it. It still does not feel like an ending. You get scans for years. That is normal, and the section below says when they can stop.

Everyday life: work, driving, seizures and tiredness

Tiredness is the symptom people underestimate, both before and after treatment. It is not laziness and it is not depression, though it can look like both from the outside.

Seizures happen with some meningiomas, mostly the ones on the surface of the brain. Read what to do when someone has a seizure before you need it. Living with seizures is about the days when nothing is happening. Anti-seizure medicines covers the tablets.

Driving depends on where you live and on whether you have had a seizure. The answer is set by whoever gives out licenses where you are, so this page does not print one. Driving and seizures has the shape of it and where to look yours up.

Work. Many people go back. What gets in the way is usually the tiredness and the concentration rather than anything dramatic, and those are the things adjustments help with most.

Changes in personality and memory are real, common with tumors near the front of the brain, and easy to mistake for the person choosing to be difficult. Saying it out loud at an appointment is worth more than managing it privately.

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

Scans go on for a long time with this diagnosis. For once there is something worth waiting for at the end of them.

The wait for the result is harder than the scan, which trips people up. Follow-up scans goes through how one scan is set against the last, and what to do with the waiting.

If your meningioma was found by chance and is being watched, the long-term studies of tumors like that are reassuring. Growth tends to slow down after the first couple of years, and after several more years it slows almost to nothing. That is the growth slowing, not the tumor shrinking. The counterweight is on watching a tumor, step by step, which has the study where more people ended up having treatment than not. And when a tumor turns out to be one of the ones that limits itself, it usually keeps doing that. Your own intervals are your team's to set.

And if you had a grade 1 meningioma taken out completely, the scans can eventually stop. In the work that surveillance plans are built on, no tumor of that kind came back after eleven clear years. Eleven years is a long time to be watched, and it is not forever. That is worth knowing at the start of it rather than at the end.

For a grade 2 or grade 3 tumor, or one where some was left behind, watching carries on. Ask your own team what yours looks like and what would change it.

If it comes back, or changes

A grade 1 meningioma can come back, and that does not mean anybody got anything wrong.

This is the clearest thing to understand about this tumor. A meningioma grows from the coverings. An operation takes out the lump, and where it is safe, the piece of covering underneath it. Sometimes the tumor is wrapped around a nerve or a large vein. Leaving a little behind is then the right decision rather than a mistake, because taking it would cost you something you use. If any of the cells it grows from are still there, it can slowly grow again from them.

That is why "not cancer" and "completely removed" are two separate statements, and why scans carry on for years after a grade 1 tumor.

The shape of it, without numbers: grade 1 comes back rarely, and after about a decade it essentially stops. Grade 2 comes back often enough that radiation after surgery is usually advised. Grade 3 comes back often and early, which is why it is treated firmly from the beginning.

If it does come back, the choices are the ones you have already met. Surgery again. Radiation, where there is room to give it. Or a trial. Which of those is open depends on what was done last time and where the tumor sits.

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.

Two things are worth naming for meningioma specifically, because they are real.

Radiation to the head, long ago. People who had radiotherapy to the head as children, for cancer or for old skin conditions, have a higher chance of a meningioma decades later. This is an established link. It is not the same thing as a dental x-ray or a CT scan. The evidence comes from doses far larger than anything used for imaging, and your head scan did not cause this. If you did have childhood radiotherapy, say so, because it changes how closely you are watched.

The hormone medicines above. This one is different from the others on this page, because it is the only one where there is something to do rather than something to absorb. It is still not a thing you did wrong. Those medicines were prescribed to you.

What might happen over time

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.

Three things that belong to this tumor in particular.

The changes you are seeing may be the location. A meningioma near the front of the brain can flatten somebody's personality. It can blunt their drive, or take their sense of smell. None of that looks like illness from the outside. It looks like them being different. Say what you have noticed, at the appointment, in front of them. Nothing else you do will help the team more.

"Not cancer" will be said to you, and it will not settle anything. People outside will hear "benign" and expect you to be relieved. You may be dealing with somebody facing brain surgery, or years of scans, or a change in who they are. Both things are true and you do not have to pick one to say out loud.

Go with them to the appointment where the medicine list comes up. The hormone question above is easy to forget in a room where somebody has just been told they have a brain tumor. It is one of the few things here with a clear action attached.

What to ask your team

• Is it on the covering of my brain, or in my brain?
• Where exactly is it, and what is it near?
• Why is the size not the main thing here?
• What grade is it, and did that come from tissue or from the scan?
• If I have not had surgery, how sure is the grade?
• Are we watching it or treating it, and why that?
• What would make you change the plan?
• If surgery is the plan, how much do you expect to be able to take out, and what decides that?
• What should I expect to get back afterwards, and what might not come back?
• Does my report say brain invasion, and what does that change?
• Am I on any hormone medicine that should be reviewed? Here is the box.
• If I had radiotherapy as a child, could that have caused this?
• Is this linked to NF2-related schwannomatosis, and should anyone in my family be checked?
• How long will I have scans, and is there a point where they stop?
• If it comes back, what then?

Where to get support

• Get help now if you want to talk to a person today.
• Brain tumor types for the other pages on this site.
• Watching a tumor, step by step if that is your plan.
• Follow-up scans for the waiting.