If imaging tests show there may be a brain tumor, a biopsy is usually done to confirm the diagnosis and determine what type of tumor it is. A biopsy is a piece of tumor tissue which is surgically removed in order to examine more closely. This can be done during surgery to remove the tumor or as a separate procedure.

Types of biopsies:

  • Open Biopsy: A biopsy may be done during surgery (called a craniotomy) in which all or part of the brain tumor is removed. If a tumor is difficult to reach during surgery, a CT (computed tomography) scan may be used for 3-D needle placement (stereotactic biopsy). This helps doctors precisely locate the tumor. Because it is often crucial to remove as much of the tumor as possible during surgery, it is critical to find a qualified surgeon.
  • Stereotactic (needle) Biopsy: This method may be used if the tumor is in a place that makes surgery too risky or difficult.

The sample tumor is analyzed by a pathologist (a doctor specializing in tissue cell and organ evaluation) to determine the final diagnosis.

The biopsy can also reveal the type and grade of the tumor and helps in determining treatment.