Diagnosing Brain & Spinal Cord Tumors in Children

Brain and spinal cord tumors are abnormal growths of cells in the central nervous system. Some tumors are benign, or noncancerous; others are malignant, or cancerous. Doctors at the Stephen D. Hassenfeld Children’s Center for Cancer and Blood Disorders, part of Hassenfeld Children’s Hospital at NYU Langone, diagnose the type of tumor based on its location, how fast it’s growing, and the type of cells it contains.

Symptoms of brain and spinal cord tumors in children usually depend on the location and size of the tumor. The most common symptoms include nausea and vomiting, a headache that goes away after vomiting, a loss of balance, seizures, sleepiness, and trouble hearing, speaking, or seeing.

Since an infant’s skull is still developing, brain tumors can sometimes increase the size of a baby’s head. In children, spinal cord tumors can cause back pain, a change in bowel movements or urination, and leg weakness, which leads to trouble walking. Brain and spinal cord tumors can also interfere with a child’s growth and cause abnormal weight gain or loss, which may be detected during checkups.

After performing a physical exam and taking a medical history, your child’s doctor orders tests that can help identify the type and severity of a brain or spinal cord tumor. Our neurosurgeons diagnose some tumors with a biopsy, or tissue sample, which is analyzed in a laboratory. The results of these tests enable the doctor to determine the best course of treatment.

Blood Test

Germ cell tumors may secrete chemicals into the blood that can be detected in the laboratory. If a germ cell tumor is suspected, our specialists may take a sample of your child’s blood to check for a tumor marker, a substance in the blood that indicates the presence of a malignant tumor in the body.

Neurological Exam

The doctor checks your child’s balance, coordination, reflexes, and senses of smell, hearing, touch, and vision. Depending on your child’s age, the doctor may evaluate memory and mental status by checking behavior, attentiveness, and thought processes. Problems in any of these areas can help the doctor pinpoint the location of the tumor, which can provide clues about the type of brain tumor that may be causing symptoms.

Imaging Tests

Imaging tests give your child’s doctor a detailed look at the brain and spinal cord. These images can also provide pediatric neurosurgeons and radiation oncologists information about the size and location of the tumor.

MRI Scans

An MRI scan uses a magnetic field and radio waves to create computerized, three-dimensional images of the brain and spinal cord. Your child’s doctor may also use this scan to check for metastasis, or signs that the cancer has spread to other parts of the body. It can show detailed changes in brain tissue.

During an MRI, your child lies on a table that slides into a tunnel-shaped machine. Sedation or anesthesia may be used to help young children stay still during the test. You may stay with your child during the test because there’s no radiation exposure. The test may take 30 to 45 minutes.

CT Scans

Occasionally, your doctor may order a CT scan, which uses X-rays and a computer to create three-dimensional, cross-sectional images of the brain or spinal cord.

The doctor injects the material into a vein, and it travels throughout the body, allowing a clear view of organs and blood vessels. The contrast fluid contains iodine, and so it’s not recommended for anyone with an allergy to seafood and iodine.

If you are accompanying your child to the CT scan, you must wear a lead apron to avoid radiation exposure. Pregnant women are advised to wait outside the room during the test. The test takes a few minutes.

Magnetic Resonance Spectroscopy Scans

A magnetic resonance spectroscopy may be performed along with an MRI to identify the molecular makeup of the tumor, which can indicate its type and aggressiveness. This scan adds 10 to 15 minutes to the MRI test.

Functional Magnetic Resonance Imaging Scans

A functional MRI shows the brain in action. Images of the brain are taken while a child performs a simple task, such as moving his or her hands. The test is sometimes used before surgery or radiation therapy to determine how a tumor is affecting a person’s movement and speech so that therapy doesn’t affect the areas of the brain responsible for these tasks. Painless electrodes are placed on the head during the MRI.


This new MRI technique allows doctors to trace “tracts” in the brain—the nerve fiber pathways that make up the brain’s white matter. Because brain tumors can displace or infiltrate these areas, it’s important that, prior to surgery, neurosurgeons map the pathways that control movement, language, and vision. This map helps them to avoid damaging these nerve fibers during surgery.


During an open biopsy, a pediatric neurosurgeon removes a small piece of the tumor, which is analyzed to determine what type of tumor it is and whether it’s benign or malignant. In children, this procedure is usually performed at the same time as surgery to remove the tumor.

For tumors that cannot be removed, or when surgery is not the primary treatment, a biopsy may be performed with methods that access the tumor from different areas. In stereotactic biopsy, a CT or MRI scan is used to guide a needle to the tumor through a small hole made in the skull. A small endoscope may also be navigated through the ventricle, the fluid-filled cavities within the brain, so that the surgeon can more easily see and remove a sample of tumor located there.

Lumbar Puncture

Your child’s doctor inserts a small needle into the lower back to withdraw spinal fluid for laboratory testing. Also called a spinal tap, this test, which is performed under general anesthesia in children, is used to determine whether cancer cells have spread beyond the brain.

Molecular Profiling Studies

Molecular profiling studies involve tests to identify the cancer’s genetic makeup and determine what is driving the tumor’s growth. This allows doctors to gather information about the cancer, including its likelihood of responding to certain treatments.

In these tests, pathologists use microscopes to analyze tissue samples collected during biopsy and identify the presence of tumor markers, which are proteins that appear in the blood and tissue when cancer is present. Different types and subtypes of cancer express different types of proteins. These studies can help your child’s doctors personalize chemotherapy treatments to your child’s needs.

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