ON THIS PAGE: You will find a list of common tests, procedures, and scans that doctors use to find the cause of a medical problem. To see other pages, use the menu.
Doctors use many tests to find, or diagnose, a tumor. Doctors may also do tests to learn which treatments could work best.
For most tumors, a biopsy is the only sure way for the doctor to know whether an area of the body has a tumor. In a biopsy, the doctor takes a small sample of tissue for testing in a laboratory. If a biopsy is not possible, the doctor may suggest other tests that will help make a diagnosis.
This list describes options for diagnosing craniopharyngioma, and not all tests listed will be used for every child. Your child’s doctor may consider these factors when choosing a diagnostic test:
The type of tumor suspected
Your child’s signs and symptoms
Your child’s age and medical condition
The results of earlier medical tests
The tests listed below may be used to diagnose craniopharyngioma. This list describes options for diagnosing craniopharyngioma, and not all tests listed will be used for every person.
Physical examination. The doctor will examine your child’s head and body and ask questions about the symptoms he or she is experiencing and his/her medical history. This may also include tests to check your child’s vision, growth and development, and brain function.
Blood tests. The doctor may recommend different blood tests, including tests that measure the levels of certain hormones.
Biopsy. A biopsy  is the removal and examination of a small piece of tumor. For craniopharyngioma, a neurosurgeon removes a sample of the tumor or the entire tumor. A neurosurgeon is a doctor who specializes in CNS surgery. Then, a pathologist looks at the tissue removed under a microscope. A pathologist is a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease. A neuropathologist is a pathologist who specializes in CNS tissues and diseases. During the surgery, a small piece of tumor may be removed at first and analyzed by the pathologist so that the surgeon knows what kind of tumor it is. Most neurosurgeons will try to remove as much of the tumor as possible once they know that it is a craniopharyngioma (see Treatment Options ).
Results of the physical examination and blood tests may suggest that imaging tests are needed to look for a craniopharyngioma. Imaging tests show pictures of the inside of the body. There are 2 main types of imaging tests used to find craniopharyngioma.
Computed tomography (CT or CAT) scan. A CT scan  creates a 3-dimensional picture of the brain using x-rays taken from different angles. A computer then combines these images into a detailed, cross-sectional view that shows abnormalities, including tumors. Sometimes, a special dye called a contrast medium is given during the scan to provide better detail. This dye is injected into a patient’s vein.
Magnetic resonance imaging (MRI). An MRI  uses magnetic fields, not x-rays, to produce detailed images of the brain and/or spinal column. An MRI scan can also be used to measure the tumor’s size. A special dye called a contrast medium is given before the scan to create a clearer picture. This dye is injected into a patient’s vein.
After diagnostic tests are done, your child’s doctor will review all of the results with you.
The next section in this guide is Stages . It explains that doctors do not commonly use stage to describe craniopharyngioma. Or, use the menu to choose another section to continue reading this guide.