Biopsy: how tissue is taken

How a piece of a brain tumor is taken, through a needle or during an operation. What the day is like. And what happens if the sample does not give an answer.

The short version

A biopsy takes a small piece of the tumor so a lab can say what it is. It can be done through a needle, using a scan as a map, or as part of an operation to take the tumor out. It is not a treatment. It is how the tumor gets its name, and the name is what your treatment is chosen from. Most of the time it gives an answer. Sometimes it does not, and this page says what happens then.

What is a biopsy?

It is taking a small piece of the tumor out so it can be looked at and tested.

A scan can show where a growth is and how big it is. Often it can give your doctors a good idea of what type it is. It cannot make that certain. Only the tissue itself can do that.

There are two main ways to get it.

Through a needle. The surgeon makes a small cut in your scalp and drills a small hole in the skull. A hollow needle goes through the hole and into the tumor, and takes out small samples. Surgeons call the small hole a burr hole. This whole thing is called a stereotactic biopsy, or a needle biopsy.

During an operation. If the plan is to take the tumor out anyway, the tissue is taken then, and no separate biopsy is needed. That operation is a craniotomycraniotomy: An operation that opens a window in the skull to reach the brain. The piece of bone is put back at the end and fixed in place. See the glossary. A craniotomy, step by step goes through it.

So a biopsy can be a procedure on its own, or it can be part of surgery.

Why am I having one?

A needle biopsy is used when a sample is needed but taking the tumor out would be too risky. That is usually because of where the tumor sits: deep in the brain, or right next to something you would not want damaged.

A needle biopsy is not an attempt to remove the tumor. It is there to get an answer, and that is all it is there for. If you were expecting the tumor to come out, this is worth being clear about before the day.

It is a fair question to put to your team, and they are used to being asked it. Ask which of the two you are having, and why they chose it.

What happens, step by step

The rest of this page is about the needle biopsy. If your tissue is being taken during an operation to remove the tumor, a craniotomy, step by step is your page instead: the day, the stay and the recovery are all different.

1. A scan first. You have an MRI or a CT that the surgeon will navigate by. Small markers may be stuck on your scalp for it. A computer turns the pictures into a map of the inside of your head, and that map is called neuronavigation. The scan just before surgery goes through that appointment, and your CT scan covers it when the map is made from a CT instead.
2. Asleep, or awake. A needle biopsy can be done under general anesthesia, so you are asleep. It can also be done with you awake, with the skin numbed where the cut goes. Ask which yours will be.
3. Your head is kept still. In one method a rigid frame is fixed to your head and the scan is used along with it. In the other there is no frame, and the computer map does the guiding. Studies that have compared the two have not found much between them, and the frame is used less often than it used to be.
4. The cut and the hole. A small cut in the scalp, then a small hole in the skull.
5. The samples. The needle is passed to the tumor and takes small pieces of it. Several samples are taken, not one.
6. A quick look, often right there. A piece is often sent straight to the lab while you are still in the room, to check that there is tumor in it. If there is not, the surgeon can take more before you leave. Your team may call that quick check a frozen section.
7. Closing up. The cut in the scalp is closed.
8. A scan afterwards. Your head is scanned again, usually within a few hours, to check that nothing is bleeding.

How long does it take?

Ask your own team about the day itself, because it depends on where the tumor is and on how your hospital runs. What follows is the shape of it.

• The scan for the map: a separate appointment before the biopsy. Ask when yours is.
• The check scan afterwards: usually a few hours later.
• Going home: some people go home the same day. Some stay the night. Which one you get depends on how your hospital is set up and on whether you fit the checklist they use, more than on how the biopsy went. Ask beforehand, so somebody knows whether to plan for a night.
• The first word on what it is: sometimes the same day, from the quick look.
• The full answer: at least a few days, and often longer, because gene tests are usually run on the tissue as well.

That last wait is the long one, and it has its own page. Waiting for your pathology results explains what is happening to your tissue in that gap, and why the name you are given can change while you wait.

What does it feel like?

If you are asleep, you feel none of it.

If you are awake, the skin where the cut goes is numbed first. The skull and the brain do not feel pain. There is nothing in the brain itself to feel the needle with. That is strange to read and it is true, and it is why this can be done at all with someone awake.

Afterwards, you may have a headache, and you may feel tired. It does not usually hurt much, and there is pain medicine if you need it. Ask for it rather than waiting to be offered.

The wound is small. It is one small cut, not the long one people picture when they hear the word surgery.

What can go wrong?

Your team will go through your own risks with you before you sign anything, and that conversation is the one that is about you.

There is no percentage here, and there is a reason worth knowing. The published rates for bleeding after a biopsy run from very low to very high, and most of that gap is about what each study counted as bleeding, not about how risky the procedure is. A number pulled out of that spread would tell you less than nothing.

Bleeding is the main one. A small amount of bleeding where the needle went is common, and most of it causes no symptoms at all. It is picked up on the scan afterwards, and often nothing needs doing about it. Looking for it is what that scan is for.

The other risks include an infection, a seizure, and bruising and swelling around the spot. Bigger bleeding, and a new problem with speech, movement or strength, are not common, which is the honest shape of it without a number. The consent form names the rarer and more serious ones as well, and going through it with you is what that conversation before the day is for.

Two things make bleeding more likely, and neither of them is about you. One is a small target, because a small one is harder to hit cleanly. The other is bleeding during the procedure itself, which your surgeon can see happening.

You may be given steroid medicine before or after, to settle swelling in the brain. Steroids says what that medicine does, and why a team sometimes wants the sample taken first.

That is what the watching afterwards is for. Someone checks on you, you get the scan, and you are told what to look out for at home. The list is further down this page, and it is worth reading with whoever is taking you home.

The hard parts, and what helps

Waiting on an answer you thought you were about to get. The biopsy is the step that gets the answer, so it is easy to expect the answer that day. Usually what you get that day is "there is enough tissue", and the name comes later. Ask before you leave: when will I hear, and who is going to call me?

Being awake for it, if you are. Nobody has to guess what that will be like. Ask what you will be able to feel, what you will hear, and what they will do to keep you comfortable. Ask what happens if you want it stopped.

The frame, if you are having one. A frame fixed to your head is the part people find hardest to picture. Ask your team whether you are having one at all, and if you are, ask them to talk you through how it goes on and how long it stays on.

Not knowing what to hope for. A lot of people come out of this not sure whether they want the answer to come quickly. That is an ordinary way to feel and it does not need fixing. If it is sitting on you, there are people you can say it out loud to today. Get help now has the numbers.

Is there a way to find out without one?

Usually not. For most brain tumors, tissue is the only thing that can give the tumor its name, and the name is what treatment is chosen from.

There are exceptions worth knowing, and two of them come up often enough to name here. Both are rare, and both are your team's call rather than something to ask for.

A place that is hard to take a sample from. If a tumor sits somewhere like the brain stem, a scan may sometimes give enough information on its own.

A tumor that blood and fluid tests can point to. For one rare group of tumors, an expert group from Europe and North America says tests on the blood and on the fluid around the brain and spine can sometimes be enough on their own. Germ cell tumor in the brain goes through which kinds that covers.

If you are worried about having the procedure at all, say that to your team rather than to nobody. There may be more than one way forward, and the conversation is a normal one to have.

What you need first, and what to bring

Before the day:

• The scan for the map. If markers are stuck on your head for it, leave them alone until you are told otherwise.
• Tell them everything you take. Prescriptions, things you buy yourself, vitamins, the lot.
• Ask which medicines to keep taking, and which to stop. Take what you are prescribed exactly as you are told, and do not stop anything on your own. Getting ready for surgery is about that conversation, and it has a section on blood thinnersblood thinner: A medicine that makes it harder for your blood to clot. Aspirin is one. And there are several others. Never stop one on your own before an operation. Your team decides that. And each medicine is different. See the glossary.
• Ask what time to stop eating and drinking, and follow the times your own hospital gives you rather than any you read anywhere else. When do I stop eating and drinking? explains what the times are usually based on, and what to ask about them.
• Ask whether any hair will be shaved, and where. It varies, and it is easier to know beforehand.

Bring:

• A list of your medicines, with the doses.
• Your questions, written down.
• Someone to get you home. You must not drive after a brain biopsy. That is not only the drive home. Your surgeon tells you how long it lasts and when it is safe to start again, so ask before the day rather than after it.
• Someone who can stay with you. If you go home the same day, an adult stays with you for the first day and night.

For the person going with them

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.

For this one day, your job is small and specific.

Getting them home, and staying. Ask before the day whether they are going home afterwards or staying in. If they are coming home the same day, an adult stays with them for the first day and night, so work out early who that is rather than at nine at night.

No driving. Not that day, and not after it either, until their team says it is allowed. Ask how long, and ask in front of them, because this is the rule people bend first.

The wound. It is small, and it still needs looking after. Ask how it is closed, whether the stitches dissolve or need taking out, and if they do, make sure that appointment exists before you leave.

What normal looks like for the next day or two. A headache. Being tired. Wanting to sleep a lot more than usual. None of that means anything has gone wrong.

Call the team the same day if:

• The wound opens, or gets more painful, red, warm or swollen.
• Anything leaks from the wound.
• There is a fever, or a stiff neck.
• The headache is new, or worse, or comes with throwing up.
• They are confused, or cannot think clearly.
• There is a sudden change in vision.
• They are sleeping much more than they are awake.
• A fall, or a hit to the head.
• Pain that the pain medicine is not touching.

Call an ambulance. These cannot wait:

• They are not breathing properly.
• You cannot wake them.
• A seizure that is their first, or that lasts more than five minutes, or that runs straight into another. (Not every seizure needs an ambulance. The seizure page above says which do.)
• They suddenly cannot speak, move, or see.
• Chest pain, or coughing up blood.

If you are not sure which list this is, call.

Why am I having another one?

Being told you need another biopsy is a hard thing to hear, and it is not a sign that anything was done badly.

Most of the time a biopsy gives an answer. Sometimes the piece that came out does not hold enough tumor to name, and then the question is how to get more. The most likely reason is simply that the target was small. In one study of frameless biopsies, the size of the tumor was the thing that decided whether the sample gave an answer, more than anything else about the patient.

This is also why the surgeon often has a piece checked while you are still in the room. If that check comes back empty, more can be taken there and then, which is the whole point of doing it at that moment.

If you are told the sample was not enough, the useful questions are: what would another one tell us that we do not know now, and what happens to my treatment while we get it.

Who reads it, and how do I get the result?

Your tissue goes to a pathologist, or to a neuropathologistneuropathologist: A doctor who works out what a tumor is by looking at the tissue itself. They specialize in the brain and the nerves. You do not usually meet them, but they are the person who names your diagnosis. See the glossary, which is a pathologist who works on the nervous system.

The report goes back to the doctor who ordered it, usually your surgeon or the specialist looking after you, and that doctor is the one who explains it to you.

One worry is worth answering here. A needle sample is small, and people ask whether it is enough for the gene tests. In one study of eighty of these biopsies, every sample was enough for the usual gene tests to be run on it. A wider test was tried on a few of them and worked on nearly all of those.

You may be told part of it quickly and the rest later. The quick look during the procedure can give a first idea the same day. The full answer takes longer, because the tissue has to be prepared and the gene tests have to be run. Waiting for your pathology results is about that gap. When the report itself arrives, your pathology report, part by part walks down one.

Before you leave, ask who will call you and roughly when, and ask for that appointment to be booked while you are standing there.

What to ask your team

• Is this a biopsy only, or an attempt to take the tumor out?
• Why this way rather than the other one?
• Will I be asleep or awake?
• Will I have a frame on my head?
• Will any of my hair be shaved, and where?
• Which of my medicines do I stop, and which do I keep taking?
• Am I going home the same day, or staying in?
• Does somebody need to be with me overnight?
• How is the cut closed, and does anything need taking out later?
• Which tests will be run on my tissue, and where are they sent?
• When will I hear, and who is going to call me?
• What happens if the sample does not give an answer?

Where to go next

• Waiting for your pathology results for what happens to your tissue next, and why the wait is what it is.
• Your pathology report, part by part once the report is in your hands.
• A craniotomy, step by step if your tissue is being taken during an operation to remove the tumor.
• Your MRI scan for the scan that comes before this one.
• The words on your gene results for the tests that get run on the tissue afterwards.
• Get help now if you need to talk to a person today.