A biopsy is a surgical procedure to remove a small sample of brain tumor tissue for examination under a microscope. It is usually performed at the same time as the surgery to remove a brain tumor (called an open biopsy). A biopsy can be performed as a separate procedure if:
- The tumor cannot be removed without damaging critical parts of the brain
- The patient is not a surgical candidate
A pathologist will examine the sample to determine the exact type of tumor, whether it is malignant and its severity (its grade).
If doctors cannot perform a biopsy, they will diagnose the brain tumor and plan the patient's treatment based on other test results.