Glioma and glioblastoma are two types of nervous system tumors. These two terms sound similar, but there are many fundamental differences between the two. Being diagnosed with a brain tumor is bad news for everybody but the type of the tumor makes a world of difference. That is why it is important to understand the basic differences between two tumors like glioma and glioblastoma.
Glioma is a tumor originating from glial cells of the brain. Glial cells are interstitial cells of the central nervous system. Central nervous system is made up of neurons and support cells. Glial cells play that supporting role. There are many types of glial cells, and the tumors that arise from each type is named according to the cell type of origin. Ependymoma, astrocytoma, oligodendroglioma and mixed glioma are such tumors. The World Health Organization classifies gliomas as high grade or low grade. Low grade tumors are well differentiated and contain matured cells. It, therefore, has benign characteristics. Low grade tumors have a better prognosis than the high grade ones which are poorly differentiated and are malignant tumors. Low grade tumors grow very slowly, and most of the time can be followed up regularly without surgical treatment unless it becomes symptomatic. High-grade tumors are notorious because they almost always regrow even after complete surgical removal. High-grade tumors are very vascular and destroy the blood brain barriers in its vicinity. Glial cell tumors are classified according to the site, as well. Tumors located above the tentorium cerebelli, which divides the cerebrum from the cerebellum, is classified as a “supra-tentorial”, while those below are classified as “infra-tentorial”. Pontine gliomasa is located in the pons of the brainstem. The site is very important because the presenting symptoms vary according to the tumor site. Glioma near the optic nerve will present with loss of vision. Gliomas near cranial nerves will present with palsies of respective cranial nerves. In general gliomas present with headache, fits, nausea and vomiting. Gliomas do not spread via the blood stream as like other malignant tumors. However, there is a chance of a spread along the cerebrospinal fluid flow giving rise to “drop metastases”. Treatment plan depends on the grade, location and symptoms. Surgical resection, radiotherapy, and chemotherapy may be utilized to treat gliomas.
Glioblastoma, on the other hand, is the most invasive primary brain tumor known to man. It is also the commonest primary brain tumor. Glioblastoma also causes headache, nausea and vomiting, but the most significant presenting feature is the progressive loss of memory, personality and other neurological deficits arising from temporal lobe involvement. Like in glioma the location is extremely important in symptomatology. Known risk factors for glioblastoma are age above 50, Asian, Caucasian race, male sex, past history of astrocytoma, and presence of genetic disorders like neurofibromatosis, Turcot’s and Von Hippel Lindau syndrome. Treatment is a challenge because tumor cells are resistant to routine treatments. Symptomatic treatment, surgery, radiotherapy, and chemotherapy may be administered with varying degrees of success. Median survival without treatment for glioblastoma is 3 months while one may continue up to a year with treatment.
What is the difference between Glioma and Glioblastoma?
- Glioma may or may not be malignant while glioblastoma invariably is.
- Glioma has a better prognosis than glioblastoma.
- Glioma presents mainly with headache, nausea vomiting while glioblastoma presents with altered higher brain functions.