A glioma is a type of cancer that starts in the brain or spine. It is called a glioma because it arises from glial cells. The most common site of gliomas is the brain
Gliomas are classified by cell type, by grade, and by location.By type of cellGliomas are named according to the specific type of cell they most closely resemble. The main types of gliomas are:
Ependymomas — ependymal cells
Astrocytomas — astrocytes - Glioblastoma multiforme is the most common astrocytoma.
Oligodendrogliomas — oligodendrocytes
Mixed gliomas, such as
oligoastrocytomas, contain cells from different types of glia
By gradeGliomas are further categorized according to their grade, which is determined by pathologic evaluation of the tumor
Low-grade gliomas are well-differentiated (not anaplastic); these are benign and portend a better prognosis for the patient.
High-grade gliomas are undifferentiated or anaplastic; these are malignant and carry a worse prognosis
By locationGliomas can be classified according to whether they are above or below a membrane in the brain called the tentorium. The tentorium separates the cerebrum, above, from the cerebellum, below.
supratentorial: Above the tentorium, in the cerebrum, mostly in adults (70%). Senator Edward M. Kennedy’s brain tumor, for example was supratentorial, in the parietal area in the upper part of the left side of his brain, above the ear.[4]
infratentorial: Below the tentorium, in the cerebellum, mostly in children (70%
SymptomsSymptoms of gliomas depend on which part of the central nervous system is affected. A
brain glioma can cause
headaches, nausea and
vomiting, seizures, and cranial nerve disorders as a result of increased intracranial pressure. A glioma of the optic nerve can cause visual loss. Spinal cord gliomas can cause pain, weakness, or numbness in the extremities. Gliomas do not metastasize by the bloodstream, but they can spread via the cerebrospinal fluid and cause "drop metastases" to the spinal cord.
TreatmentStandard therapyTreatment for brain gliomas depends on the location, the cell type and the grade of malignancy. Often, treatment is a combined approach, using surgery, radiation therapy, and chemotherapy. The radiation therapy is in the form of external beam radiation or the stereotactic approach using radiosurgery. Spinal cord tumors can be treated by surgery and radiation. Temozolomide is a chemotherapeutic drug that is able to cross the blood-brain barrier effectively and is being used in therapy
Sources:
http://en.wikipedia.org/wiki/Gliomahttp://www.youtube.com/glioma
