During a biopsy, a small piece of the tumour is removed to be examined under a microscope. This test provides doctors with information about the type of cell the cancer developed from. It’s used to see what type of tumour you have.

A scan (brain MRI scan or CT scan) is done to locate the tumour. Then a small hole is made in the skull and fine needle is then passed through the hole to remove a sample of the tumour. If the tumour is deep inside the brain, you may have a guided biopsy:

  • by stereotactic biopsy – you’ll be fitted with a head frame that’s used to help guide the needle to the tumour.
  • by neuronavigation – markers are placed on your head before the scan. They’re used as guides to help direct the needle to the tumour.


A biopsy is when the surgeon removes a piece of the tumour. This can then be examined by a doctor who studies cell types (pathologist). They do tests to find out the type and grade of the tumour and check for biomarkers.

There are different ways to take a brain biopsy. Your surgeon will explain what to expect in your situation. Sometimes it is only safe to remove a tiny part of the tumour to look at under the microscope. But often the biopsy is taken as part of a larger operation to remove the tumour.

You usually have a biopsy taken under a general anaesthetic. But sometimes a local anaesthetic is used. During the operation the surgeon may take the biopsy:

  • through a small hole they drill in the skull (burr hole)
  • by removing a small area of skull over the tumour (craniotomy). This is called an open biopsy.

The surgeon uses scans taken before and sometimes during the operation to guide them while taking the biopsy.

Guided biopsy

You may have a guided biopsy if the tumour is deep inside the brain. This can be done using a stereotactic biopsy or a neuronavigation biopsy.

To have a stereotactic biopsy, you need to be fitted with a head frame. The surgeon uses the frame and information from scans, which are fed into a computer, to guide the biopsy needle to the exact place. You usually have this done under a general anaesthetic, but occasionally a local anaesthetic is used.

If you have a neuronavigation biopsy, you don’t need a head frame. The surgeon uses a scan to guide the biopsy needle to the right place. Before the scan, you may have markers taped on parts of your head. These are called fiducial markers. They show up on the scan and also help the surgeon find the affected area.

Back to Surgery explained

When is surgery used?

Surgery can be used to remove all or part of the tumour or to give chemotherapy into the brain.


The surgeon removes all or as much as possible of the brain tumour with an operation called a craniotomy.

Having your operation

A team of healthcare professionals will help you before and after surgery for a brain tumour.


A shunt is a thin tube that drains extra fluid away from the brain to relieve raised intracranial pressure.

What happens before surgery?

To prepare for your operation, you’ll have some tests and may be given steroids. If you smoke, try to give up or cut down.

Who might I meet?

A team of specialists will plan your surgery. This will include a surgeon who specialises in your type of cancer.

What happens after surgery?

You'll be monitored closely after your operation. You may have a drip (infusion) giving you fluids for a short while.