A brain tumor is a growth in the brain. Tumors are characterized by either benign and malignant features.
Gliomas are the most frequent tumors of the central nervous system with a share of 30-50%. Approximately 7-11 out of 100,000 people develop gliomas each year. Gliomas are tumors of the brain, i.e. they develop from the supporting and nourishing tissue of the nerve cells, the glial cells. They usually grow in the brain, but also occur in the area of the spinal cord and cranial nerves. Depending on the localization, different symptoms appear, such as headaches, impairment of mental abilities (neurocognitive deficits), epileptic seizures, speech disorders or paralysis.
In order to maintain a better overview of this very large and heterogeneous group of tumors, the World Health Organization (WHO) initially divides them into four grades from low-grade, i.e. benign according to fine-tissue criteria, to high-grade, i.e. malignant according to fine-tissue criteria. The four grades are each assigned Roman numerals, i.e. WHO grade I-IV. In addition to this rough classification, however, there are further categories that are determined according to immunohistochemical and molecular pathological features. Simplified, it can be said that the tissue in which the tumor begins to grow determines the name: pilocytic astrocytoma, ependymoma, hemangioblastoma, oligodendroglioma, oligo-astrocytic glioma, anaplastic glioma, glioblastoma, or gliosarcoma.
Genetic characteristics are also increasingly playing a central role and a corresponding "molecular pathological fingerprint" has been created. For the layperson, this classification may seem complicated and confusing. However, it is important to know that therapy decisions and statements on the possible prognosis of the disease are made on the basis of this classification.
After the diagnosis has been made, interdisciplinary consensus is reached on further examination of the tissue and/or removal of the tumour. In case of surgery, "high-tech" procedures such as intraoperative neuronavigation, neuroendoscopy in combination with high-resolution surgical microscopes, intraoperative imaging by means of magnetic resonance imaging (MRI) or ultrasound and neurophysiological monitoring are available.
If a histological examination confirms the diagnosis of glioblastoma—that is, a tumor of the highest grade—the standard treatment usually involves its complete removal with the highest possible degree of safety, followed by a combination of radiation therapy and chemotherapy.
In the case of lower-grade gliomas (WHO Grade I–II), treatment may sometimes consist solely of follow-up care, including monitoring for any symptoms that may arise and MRI imaging. Other types of tumors, however, require adjuvant—that is, supplementary or supportive—therapy at this stage. The exact course of action is always tailored to the individual patient and decided on a case-by-case basis.
