Diagnosis of Childhood Central Nervous System Tumors

Executive Summary

Childhood central nervous system (CNS) tumors are diagnosed based on signs and symptoms. Biopsy is the common diagnostic approach for childhood (CNS) tumors. Imaging tests help determine the type of tumors in the (CNS) among children. Along with physical examination in children, other tests are also done involving Magnetic resonance imaging (MRI), CT scan, and Molecular testing of the tumor.

Diagnosis of Childhood Central Nervous System Tumors

Many tests are performed to find or diagnose cancer. Also, tests are done to learn if the Central Nervous System tumor has spread to parts other than where it started. The spread of the tumor to other regions is called metastasis.

A biopsy is a sure way to know if you have cancer in a particular part or organ of the body for most types of cancer ​1​.

Imaging tests can help doctors determine if the tumor is a primary tumor or if cancer has metastasized to the brain from elsewhere in the body.

The different tests can be used for a person depending upon the following factors – 

  • Your signs and symptoms
  • The age and general health status
  • The type of cancer suspected
  • The result of earlier medical tests

In addition to the physical examinations, the below-mentioned test can be used for the diagnosis of Central Nervous System tumors ​2​:

  • Magnetic resonance imaging (MRI) – An MRI uses magnetic fields, not x-rays, to produce detailed body images. A specific dye known as contrast medium is given before the scan to create a better picture. This dye can be injected into a patient’s vein or given as a pill or liquid to swallow.
  • Biopsy – A biopsy removes a small part of tissue to examine under a microscope. A biopsy can also be done as surgery to remove the entire tumor. The type of biopsy performed depends upon the position of the Central Nervous System tumor.
  • CT scan – A CT scan clicks pictures of the body from inside using x-rays taken from different angles. A computer combines photos into a detailed, 3-dimensional image that shows abnormalities or tumors. Changes in the skull bone can also be seen on a CT scan, and it can be used to measure a Central Nervous System tumor’s size.
  • Molecular testing of the tumor – Your doctor may recommend you to take laboratory tests on a Central Nervous System tumor sample to identify proteins, specific genes, and other factors, such as tumor markers, unique to the tumor. It is called molecular testing of the tumor. 

After diagnostic tests are done, your child’s doctor will review all of the results with you. If the diagnosis is a Central Nervous System tumor, these results help the doctor describe the tumor. This process is called staging and grading.


  1. 1.
    Goldman RD, Cheng S, Cochrane DD. Improving diagnosis of pediatric central nervous system tumours: aiming for early detection. CMAJ. Published online November 28, 2016:E459-E463. doi:10.1503/cmaj.160074
  2. 2.
    Shay V, Fattal-Valevski A, Beni-Adani L, Constantini S. Diagnostic delay of pediatric brain tumors in Israel: a retrospective risk factor analysis. Childs Nerv Syst. Published online August 26, 2011:93-100. doi:10.1007/s00381-011-1564-0