How is brain cancer diagnosed?Diagnosis of brain cancer involves evaluating symptoms and taking a medical history. Examination often shows focal (isolated location) or general neurologic changes that are specific to the location of the tumor or cancer. Some tumors may not show symptoms until they are very large and cause rapid neurologic decline, others are characterized by slowly
progressive symptoms. Most brain tumors will include signs typical of space-occupying masses (aggregations of cells) which cause increased intracranial pressure and compression of brain tissue.
The patient may have a neurological exam, which involves checking eye movements, reflexes, hearing, balance, coordination, touch, taste, smell, facial muscle movement, tongue movement, head movement, and mental status. The patient may need special tests to show the size, shape, and location of the tumor within the brain. Tests may include an x-ray, CT scan (computed tomography), PET (positron emission tomography) scan, or MRI (magnetic resonance imaging).
A biopsy will probably be done to confirm that the tumor is cancer and to find out what type of cells are involved. This can be done as part of an operation to remove the tumor, or can be done in a separate procedure where only a small sample of tissue is obtained. A needle biopsy may be used for brain tumors in hard to reach areas within the brain. The surgeon drills a small hole, called a burr hole, into the skull. A narrow, thin needle is then inserted through the hole.Tissue is removed using the needle, which is frequently guided by CT scanning.