National Organization for Rare Disorders, Inc.
It is possible that the main title of the report Astrocytoma is not the name you expected.
An astrocytoma is a tumor that arises from the star-shaped cells (astrocytes) that form the supportive tissue of the brain. Other supportive cells of the brain include oligodendrocytes and ependymal cells. Collectively, these cells are known as glial cells and the tissue they form is known as glial tissue. Tumors that arise from the glial tissue, including astrocytomas, are collectively referred to as gliomas.
The World Health Organization (WHO) classifies astrocytomas into four grades depending on how fast they are growing and the likelihood that they will spread (infiltrate) to nearby brain tissue. Non-infiltrating astrocytomas usually grow more slowly than the infiltrating forms. Infiltrating, or diffuse astrocytomas are more common than non-infiltrating astrocytomas. They are generally more common in men and are most common in the cerebral hemispheres of adult patients. In children they occur both in the cerebral hemispheres as well as the brain stem. Tumors from oligodendrocytes (oligodendrogliomas) are also in the category of infiltrating gliomas and can occasionally be difficult to distinguish from astrocytomas. Some infiltrating gliomas are categorized as mixed oligodendroglioma-astrocytoma (oligoastrocytoma).
Grade I astrocytoma is usually a non-infiltrating tumor. The most common type of grade I astrocytoma is pilocytic astrocytoma which is also known as juvenile pilocytic astrocytoma or JPA. This tumor grows slowly but can become very large. Pilocytic astrocytoma occurs most often in the cerebellum, cerebrum, optic nerve pathway and brainstem. This tumor occurs most often in children and teens and accounts for 2% of all brain tumors.
Grade II astrocytoma is also called low-grade astrocytoma or diffuse astrocytoma and is usually an infiltrating tumor. This tumor grows relatively slowly and usually does not have well-defined borders. It occurs most often in adults between the ages of 20 and 40.
Grade III astrocytoma is also called anaplastic (malignant) astrocytoma because this tumor grows more quickly than a grade II astrocytoma. Anaplastic astrocytoma occurs most often in adults between the ages of 30 and 50, and accounts for 4% of all brain tumors.
Grade IV astrocytoma is also called glioblastoma or GBM and is the most aggressive type of nervous system tumor. It is also referred to as glioblastoma multiforme because of its wide variety of appearances under the microscope. Rarely, non-glial tissue elements can exist in a glioblastoma. The most common variant of GBM showing these additional tissue elements is called a mixed glioblastoma-sarcoma, or gliosarcoma. GBM occurs most often in adults between the ages of 50 and 80, is more common in men, and accounts for 23% of all primary brain tumors.
Recently several markers have been identified in diffuse gliomas. Astrocytomas grades II and III often have acquired mutations in a gene called IDH1. These mutations ar acquired by the tumor and are not generally present in the normal cells of the patient. The presence of an IDH1 mutation in an astrocytoma is generally associated with an improved prognosis compared to an astrocytoma of similar grade that does not have an IDH1 mutation. A second marker, relevant to GBM, is MGMT methylation. When present, MGMT methylation may be associated with better response to chemotherapy (usually temozolomide) compared to GBMs without MGMT methylation.
American Brain Tumor Association
- 8550 W. Bryn Mawr Avenue, Suite 550
- Chicago, IL 60631
- Tel: (773)577-8750
- Fax: (773)577-8738
- Tel: (800)886-2282
- Email: firstname.lastname@example.org
- Website: http://www.abta.org
American Childhood Cancer Organization
- 10920 Connecticut Ave
- Suite A
- Kensington, MD 20895
- Tel: (301)962-3520
- Fax: (301)962-3521
- Tel: (800)366-2223
- Email: email@example.com
- Website: http://www.acco.org
Brain Tumor Foundation for Children, Inc.
- 6065 Roswell Road Suite 505
- Atlanta, GA 30328-4015
- Tel: (404)252-4107
- Fax: (404)252-4108
- Email: firstname.lastname@example.org
- Website: http://www.braintumorkids.org
- American Society of Clinical Oncology
- 2318 Mill Road Suite 800
- Alexandria, VA 22314
- Tel: (571)483-1780
- Fax: (571)366-9537
- Tel: (888)651-3038
- Email: email@example.com
- Website: http://www.cancer.net/
Children's Brain Tumor Foundation
- 274 Madison Avenue, Suite 1004
- New York, NY 10016
- United States
- Tel: (212)448-1595
- Fax: (212)448-1022
- Tel: (866)228-4673
- Email: firstname.lastname@example.org
- Website: http://www.cbtf.org
Genetic and Rare Diseases (GARD) Information Center
- PO Box 8126
- Gaithersburg, MD 20898-8126
- Tel: (301)251-4925
- Fax: (301)251-4911
- Tel: (888)205-2311
- Website: http://rarediseases.info.nih.gov/GARD/
Harvard Brain Tissue Resource Center
- McLean Hospital
- 115 Mill Street
- Belmont, MA 2178
- Tel: (617)855-2400
- Fax: (617)855-3199
- Tel: (800)272-4622
- Email: email@example.com
- Website: http://www.brainbank.mclean.org
National Brain Tumor Society
- 55 Chapel Street
- Suite 200
- Newton, MA 02458
- Tel: (617)924-9997
- Fax: (617)924-9998
- Tel: (800) 770-8287
- Email: firstname.lastname@example.org
- Website: http://www.braintumor.org
- 98 Random Farms Drive
- Chappaqua, NY 10514
- Email: email@example.com
- Website: http://www.fightplga.org/
Pediatric Brain Tumor Foundation
- 302 Ridgefield Court
- Asheville, NC 28806
- Tel: (828)665-6891
- Fax: (828)665-6894
- Tel: (800)253-6530
- Email: firstname.lastname@example.org
- Website: http://www.pbtfus.org
For a Complete Report
This is an abstract of a report from the National Organization for Rare Disorders (NORD). For a full-text version of this report, go to www.rarediseases.org and click on Rare Disease Database under "Rare Disease Information".
The information provided in this report is not intended for diagnostic purposes. It is provided for informational purposes only.
It is possible that the title of this topic is not the name you selected. Please check the Synonyms listing to find the alternate name(s) and Disorder Subdivision(s) covered by this report.
This disease entry is based upon medical information available through the date at the end of the topic. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder.
Last Updated: 5/15/2015
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