Glioma brain tumor or brain glioma is a tumor that is derived from the glial cells of the brain and from there it gets its name.
The most common site of gliomas is the brain (Glioma brain tumor or brain glioma). Gliomas account for ~ 30% of all brain and spinal cord tumors, accounting for 80% of all malignant brain tumors.
Gliomas are classified according to the type of cells they are composed of, to their degree of malignancy and their localization.
Depending on the type of cells gliomas have been named according to the particular type of cell that they share histological features with but not necessarily derived from.
Glioma brain tumor or brain glioma - Types
The main types of gliomas are as follows:
- Ependymomas-derived from ependymal cells.
- Astrocytomas-derived from astrocytes (polymorphic glioblastoma is the most common).
- Oligodendrogliomas-derived from oligodendrocytes.
- Mixed gliomas, such as oligoastrocytes. Τhey contain cells from different types of glia.
Each of the above categories has subcategories analogous to the origin of the cells.
Gliomas are further categorized according to their degree of malignancy which is determined by histopathological examination of the tumor.
Of the numerous classification systems for gliomas, the most common classification system for astrocytomas is that of the World Health Organization (WHO), according to which tumors are rated from: I (less advanced disease-better prognosis) to IV (the most advanced stage of the disease worse prognosis).
- Low-grade malignancy - high differentiation glioma [WHO grade I-II]. These tumors are relatively benign and have a better prognosis for the patient.
- High grade malignancy - low differentiation glioma [WHO grade III-IV].These are malignant tumors and have a worse prognosis.
Depending on the location, brain gliomas can be classified according to whether they are above or below the cerebellum tentorium. The tentorium divides the brain (top) from the cerebellum (below), separating them into:
- Hyper - tentorium: above the tentorium, in the cerebral hemispheres. Mostly they are found in adults (70%).
- Hypo - tentorium: under the tentorium, in the cerebellum and are mainly found in children (70%).
- Brain stem gliomas: These are located in the brain stem, consisting of three parts (pons, midde and medulla). The pons controls critical functions such as breathing, performing surgery in this area extremely risky.
- Optic nerve: They are localized in the nerve that connects the brain to the eye.
Glioma brain tumor or brain glioma - Symptoms
Symptoms of Glioma brain tumor or brain glioma depend on which part of the central nervous system is affected.
A brain glioma can cause:
- Seizures, and
- Cranial nerve disorders,
a result of increased intracranial pressure or of direct pressure on brain tissue.
An optic nerve glioma can cause loss of vision.
Gliomas of the spinal cord can cause pain, weakness or numbness of the limbs.
Gliomas do not give metastases through the bloodstream, but can be transmitted through the cerebrospinal fluid and affect the spinal cord.
Glioma brain tumor or brain glioma - Treatment
Treatment for Glioma brain tumor or brain glioma depends on:
- The location,
- The cell type and
- The degree of malignancy.
Often, the Glioma brain tumor or brain glioma therapeutic approach is a combination of:
- Surgery aiming at removal of as much of the tumor as possible.
- Radiotherapy, in the form of external beam radiation or stereotactic radiosurgery.
- Chemotherapy. Temozolomide is a chemotherapeutic drug that is able to cross the blood-brain barrier effectively and is currently being used in the treatment of high malignancy tumors. Also, Bevacizumab (Avastin) is a monoclonal antibody (a type of protein) designed to recognize and to the vascular endothelial growth factor (VEGF), a protein circulating in the blood that constitutes to the development of blood vessels. Through its attachment to VEGF, Bevacizumab prevents cancer cells from developing their blood supply mechanism and thus removes oxygen and nutrients, slowing the growth and spread of glioblastoma. Other chemotherapeutic agents used inter alia for relapse are nitrosoureas, Vinka alkaloids and
- In some cases some patients benefit from the implantation of local chemotherapy with carmustine polymers (Gliadel wafers).
Also, newer therapies for Glioma brain tumor or brain glioma treatment have been developed and are now available to patients at an experimental level, such as immunological vaccine-type therapies, electric field generators applied transdermally in the brain, and of course for various evolving laser and nanotechnology therapies that throw a promising light in the prognosis and treatment of patients with Glioma brain tumor or brain glioma.
Spinal cord tumors are usually treated with microsurgery and radiation.