Glioma and Glioblastoma
Glioma is a tumor that originates in some cells of the central nervous system (which includes brain and the spinal cord) called glia cells. Like any tumor, glioma is also caused by a genetic mutation, but the exact cause of this mutation is still under study.
There are different types of gliomas: their characteristics depend mainly on the type of affected cell of the glia and the speed of growth of the tumor mass. The most severe gliomas, such as the glioblastoma multiforme, are characterized by a high rate of growth.
The diagnosis of glioma is established through neurological, instrumental and laboratory tests.
By knowing the characteristics of a glioma such as site, size and gravity makes it possible to set the most appropriate therapy. Brain tumors characterized by a slow grow rate of the abnormal are considered benign while brain tumors with fast grow rate are instead considered malignant.
Primary brain tumors are those that originate directly in the brain or in parts adjacent to it. Secondary brain tumors are the result of metastasis of a tumor originating elsewhere.
Glia cells provide support and stability to the network of neurons and communicate with neurons to keep them healthy and direct their development. Based on the affected glial cells, there are different categories of gliomas: astrocytomas involve astrocytes; oligodendrogliomas involve oligodendrocytes; ependymomas affect ependymal cells; Mixed gliomas affect both oligodendrocytes and astrocytes.
Brain tumors can also be distinguished according to the degree of severity. There are four grades, from I to IV, taking into account both the growth rate and the infiltration and diffusion capacity.
Grade I and II tumors are considered slow-growing and localized on one spot; all infiltrating and rapidly growing tumors are instead considered to be of III and IV degree. Over time, it is possible that a grade I or II tumor mass will evolve and become grade III or IV.
Glioblastoma multiforme is grade IV and is an astrocytoma.
Gliomas represent about 80% of primary brain tumors and about 30% of malignant ones.
The glioblastoma multiforme, which is one of the most common and deadly tumor of the brain, affects people aged 55 and over.
Grade I and II astrocytomas usually occur in people aged 20-30, while anaplastic astrocytomas and oligodendrogliomas predominantly affect individuals in their forties.
The precise causes, which cause gliomas, have not yet been fully clarified, however, since they are a form of brain tumor, researchers believe that at the origin there is a genetic mutation against glia cells.
What triggers this mutation is still under study: the only known risk factors are some rare genetic diseases, which, being rare, cannot explain most of the gliomas and brain tumors.