Diagnosis

Tests and procedures used to diagnose pineoblastoma include:

• Imaging tests. Imaging tests can help your doctor determine the location and size of your child's brain tumor. Magnetic resonance imaging (MRI) is often used to diagnose brain tumors, and advanced techniques, such as perfusion MRI and magnetic resonance spectroscopy, may also be used.

  Additional tests might include computerized tomography (CT) and positron emission tomography (PET).

• Removing a sample of tissue for testing (biopsy). A biopsy can be done with a needle before surgery or during surgery to remove the pineoblastoma. The sample of suspicious tissue is analyzed in a laboratory to determine the types of cells and their level of aggressiveness.
• Removing cerebrospinal fluid for testing (lumbar puncture). Also called a spinal tap, this procedure involves inserting a needle between two bones in the lower spine to draw out cerebrospinal fluid from around the spinal cord. The fluid is tested to look for tumor cells or other abnormalities. In certain situations, cerebrospinal fluid may instead be collected during a biopsy procedure to remove suspicious tissue from the brain.