You usually have a biopsy taken under a general anaesthetic. Sometimes a local anaesthetic is used. The surgeon uses scans taken before and sometimes during the operation to guide them while taking the biopsy. They may take the biopsy:
- through a small hole they drill in the skull (burr hole)
- by removing a small piece of skull over the tumour (craniotomy) – this is sometimes called an open biopsy.
The tests give your doctor information about how the tumour may develop and grow. Knowing this helps them to plan the best treatment for you.