A glioma is a type of primary central nervous system (CNS) tumor that arises from glial cells. The most common site of involvement of a glioma is the brain, but they can also affect the spinal cord, or any other part of the CNS, such as the optic nerves. The human central nervous system consists of the brain and spinal cord. ... Tumor (American English) or tumour (British English) originally means swelling, and is sometimes still used with that meaning. ... Neuroglia cells of the brain shown by Golgis method. ...

Gliomas are named according to the specific type of cell they derive from. The three main types of gliomas are astrocytomas, oligodendrogliomas, and ependymomas, which are named for astrocytes, oligodendrocytes, and ependymal cells, respectively. Mixed gliomas, such as oligoastrocytomas, contain cells from different types of glia. Astrocytomas are intracranial tumors derived from astrocytes. ... Oligodendroglioma is a type of intracranial tumor. ... Ependymona are intracranial tumors arising from the inner lining of the ventricles and the spinal canal. ... Astrocytes, also known as astroglia, are characteristic star-shaped cells in the brain. ... Oligodendrocytes are a variety of neuroglia. ... Neuroglia cells of the brain shown by Golgis method. ...

Classification

Gliomas are further categorized according to their grade, which is determined by pathologic evaluation of the tumor. Low grade gliomas are well-differentiated, slower growing, biologically less aggressive, and portend a better prognosis for the patient. High grade gliomas are undifferentiated or anaplastic, fast growing and can invade adjacent tissues, and carry a worse prognosis. There are numerous grading systems, but the most commonly used system is the World Health Organization (or WHO) grading system for astrocytomas. The WHO system assigns astrocytomas a grade from 1 to 4, with 1 being the least aggressive and 4 being the most aggressive. Various types of astrocytomas are given corresponding WHO grades. A grade may refer to many different concepts, including: in various contexts: Each item in a (generally ordered and finite) collection of symbols or designators used as a particular grade system to distinguish and rank corresponding groups, where distinct members or instances of each group are regarded as sufficiently similar... Pathology (in ancient Greek pathos = pain/pation and logos = word) is the study of diseases. ... For other meanings of the acronym WHO, see WHO (disambiguation) WHO flag Headquartered in Geneva, Switzerland, the World Health Organization (WHO) is an agency of the United Nations, acting as a coordinating authority on international public health. ...

WHO grading system for astrocytomas

• WHO Grade 1 — e.g. pilocytic astrocytoma
• WHO Grade 2 — e.g. diffuse astrocytoma
• WHO Grade 3 — e.g. anaplastic (malignant) astrocytoma
• WHO Grade 4 — glioblastoma multiforme (most common glioma in adults)

The prognosis is worst for Grade-4 gliomas, with an average survival time of 14-18 months. Overall, the five year survival rate is 5%.

The gliomas can also be roughly classified according to their location:

• infratentorial : mostly in children (70%)
• supratentorial : mostly in adults (70%)

Categories: Move to Wiktionary | Substubs ... In anatomy the supratentorial is located above the tentorium cerebri. ...

Symptoms

Symptoms of gliomas depend on which part of the central nervous system is affected. A brain glioma can cause headaches, nausea and vomiting, 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. Cranial nerves are nerves which start directly from the brainstem instead of the spinal cord. ... The optic nerve is the nerve that transmits visual information from the retina to the brain. ...

Pathology

High grade gliomas are highly vascular tumors and have a tendency to infiltrate. They have extensive areas of necrosis and hypoxia. Often tumor growth causes a breakdown of the blood-brain barrier in the vicinity of the tumor. As a rule, high grade gliomas almost always grow back even after complete surgical excision. Necrosis (in Greek Νεκρός = Dead) is the name given to unprogrammed death of cells/living tissue (compare with apoptosis - programmed cell death). ... Hypoxia is a pathological condition in which the body as a whole (generalized hypoxia) or region of the body (tissue hypoxia) is deprived of adequate oxygen supply. ... The blood-brain barrier is a physical barrier between the blood vessels in the central nervous system, and the central nervous system itself. ...

On the other hand, low grade gliomas grow slowly, often over many years, and can be followed without treatment unless they grow and cause symptoms.

Treatment

Treatment for brain gliomas depends on the location and the grade. 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. Gene therapy using lytic viruses or prodrug converting retroviruses and adenoviruses is another new development for the treatment of gliomas. Temozolomide is a chemotherapeutic drug that is able to cross the blood-brain barrier effectively and is being used in therapy. Radiation therapy (or radiotherapy) is the medical use of ionizing radiation as part of cancer treatment to control malignant cells (not to be confused with radiology, the use of radiation in medical imaging and diagnosis). ... Chemotherapy (pronounced keem-o-therapy) is the use of certain drugs to treat disease, as distinct from other forms of treatment, such as surgery. ... Stereotactic surgery is a minimally-invasive form of surgical intervention which makes use of a three-dimensional coordinates system to locate small targets inside the body and to perform on them some action such as ablation (removal), biopsy, lesion, injection, stimulation, implantation, etc. ... Radiosurgery is a medical procedure which allows non-invasive brain surgery, i. ... Gene therapy is the insertion of genes into an individuals cells and tissues to treat a disease, and hereditary diseases in particular. ... The blood-brain barrier is a physical barrier between the blood vessels in the central nervous system, and the central nervous system itself. ...