Glioma is the standard type of a brain tumour in adults. Secondary brain tumours are cancers that have metastasized (spread) from elsewhere in the body.
Gliomas develop from glial cells, which are the supportive cells in the brain that help the neurons “do their job.”
This includes many cell-like oligodendrocytes, astrocytes, and ependymal cells. Hence the tumours arising from these are known as astrocytomas, oligodendrogliomas and ependymomas respectively. Oligoastrocytomas are mixed tumours containing both astrocytes and oligodendrocytes.
Pathologists examine gliomas under the microscope to determine their grade, which is based on the World Health Organisation (WHO) classification system.
Low-grade gliomas are benign and include Grade 1 or Grade 2 tumours.
High grade gliomas are malignant and include Grade 3 tumours:
Anaplastic oligoastrocytoma and Grade
Glioblastoma multiforme (GBM)