How are central nervous system (CNS) tumors graded?

The generally accepted scale for grading CNS tumors was approved by the World Health Organization in 1993. Grading is based on the tumor's cellular makeup and location. Tumors may also be classified as low-grade (slowly growing) or high-grade (rapidly growing). The grade of some tumors changes as they progress, usually to a higher grade, and they can change into a different type of tumor. The tumor is graded by a pathologist following a biopsy or during surgery.

Grade I tumors grow slowly and generally do not spread to other parts of the brain. It is often possible to surgically remove an entire grade I benign tumor; but this type of tumor may be monitored periodically, without further treatment.

Grade II tumors also grow slowly, sometimes into surrounding tissue, and can become a higher-grade tumor. The treatment varies according to the location of the tumor and may require chemotherapy, radiation, or surgery followed by close observation.

Grade III tumors are malignant and can spread quickly into other CNS tissue. The tumor cells look different from those in the surrounding tissue. Aggressive treatment, often using a combination of chemotherapy, radiation, and/or surgery, is required.

Grade IV tumors invade nearby tissue very quickly and are difficult to treat. The cancerous tissue looks very different from the surrounding tissue. Aggressive treatment is required.

This answer is based on source information from National Institute of Neurological Disorders and Stroke.

Continue Learning about Brain Cancer (Neurological Cancers)

News: Sen. John McCain To Discontinue Medical Treatment for Aggressive Brain Cancer
News: Sen. John McCain To Discontinue Medical Treatment for Aggressive Brain Cancer
The family of John McCain announced that he will no longer be receiving treatment for brain cancer. The Republican senator from Arizona has been battl...
Read More
Are seizures a symptom of a glioma or metastasis?
Patricia Bartley DanielePatricia Bartley Daniele
Seizures, associated with a glioma or brain metastasis, are related to affected areas of the brain. ...
More Answers
What are the treatment options for brain cancer?
Honor Society of Nursing (STTI)Honor Society of Nursing (STTI)
Different types of brain cancer need different treatment. You may need surgery to remove the tumor, ...
More Answers
Inside Big Ang’s Cancer Treatment
Inside Big Ang’s Cancer Treatment

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.