The Types of Brain Cancer
Brain tumors are broadly classified based on where they originate (primary or metastatic) and the type of cell they arise from.
Here is an overview of the types of brain cancer and tumors:
1. Primary Brain Tumors3
These tumors originate within the brain or spinal cord tissue.
A. Gliomas (The Most Common Type)
Gliomas arise from glial cells, the supportive cells of the brain.
| Type of Glioma | Originating Cell | Common Grade | Key Characteristics |
| Glioblastoma (GBM) | Astrocytes (or mixed) | Grade IV (Highest) | The most common and most aggressive, malignant (cancerous) primary brain tumor in adults. |
| Astrocytoma | Astrocytes | Grade II, III, or IV (GBM) | Can occur throughout the brain; often infiltrative (grow into surrounding tissue). |
| Oligodendroglioma | Oligodendrocytes | Grade II or III | Arise from cells that produce myelin; often have specific genetic markers that can predict treatment response. |
| Ependymoma | Ependymal cells (lining the ventricles) | Grade I, II, or III | More common in children and often found in the cerebellum or spinal cord. |
B. Non-Glial Primary Tumors
These tumors arise from other structures surrounding the brain:
| Tumor Type | Originating Tissue | Typical Nature | Key Characteristics |
| Meningioma | Meninges (membranes covering brain/spinal cord) | Usually Benign (Grade I) | The most common primary brain tumor; typically slow-growing and more common in women. A small number are malignant (Grade II or III). |
| Medulloblastoma | Embryonal cells in the cerebellum | Malignant (High Grade) | Highly aggressive; one of the most common malignant brain tumors in children. |
| Pituitary Adenoma | Pituitary gland | Usually Benign | Slow-growing; can affect hormone production. |
| Schwannoma (Acoustic Neuroma/Vestibular Schwannoma) | Schwann cells (on nerves) | Usually Benign | Develops on the vestibular nerve (balance/hearing); slow-growing. |
| Primary CNS Lymphoma | Lymphatic cells | Malignant | A rare, aggressive cancer of the immune cells that starts in the brain or spinal cord. |
2. Metastatic (Secondary) Brain Tumors8
These are cancers that start in another part of the body (e.g., lung, breast, skin/melanoma, colon) and spread to the brain.
Key Fact: Metastatic tumors are far more common than primary brain tumors.
10 The tumor is named and treated according to the tissue of origin (e.g., metastatic lung cancer to the brain).
11
The WHO Brain Tumor Grading System
The World Health Organization (WHO) classifies brain tumors into four grades based on how the cells look under a microscope (histology) and their likely behavior:
| WHO Grade | Classification | Characteristics |
| Grade I | Benign / Low-Grade | Slowest growing; least malignant; often curable with surgery alone. |
| Grade II | Low-Grade | Grow slowly but may spread into nearby tissue; can potentially recur as a higher grade. |
| Grade III | Malignant / High-Grade | Faster growing; cells are abnormal (anaplastic); likely to recur. |
| Grade IV | Malignant / High-Grade | Fastest growing; most aggressive and invasive (e.g., Glioblastoma). |
There are over 100 types of cancer that can affect the central nervous system (CNS).16 As mentioned previously, cancers that arise in other locations (breast, lung, etc.) and spread (metastasize) to the brain are not considered brain cancer. They are still treated as the cancers of the original site. Here, we will only discuss primary brain cancers (those that originate in the brain).
Gliomas
Malignant gliomas are the most common and deadly brain cancers. They originate in the glial cells of the central nervous system (CNS). Gliomas can be divided into 3 main types:
- astrocytomas,
- oligodendrogliomas, and
- ependymomas.
The median survival of patients with glioma has improved over the past few years but is still only 15 months, with few patients living more than two years.Research indicates that this type of brain cancer may resist treatment because it contains stem cells that are responsible for driving the formation of blood vessels (angiogenesis), spread of the tumor (metastasis), and resistance to treatments.
- Astrocytomas:
Astrocytomas are tumors that develop in astrocytes and are found in the cerebrum and the cerebellum. Astrocytomas make up approximately 50% of all primary brain tumors. Glioblastoma multiforme, an astryocytoma subtype, is the most aggressive form of brain cancer and is associated with poor prognosis.
- Oligodendrogliomas:
Oligodendrogliomas are tumors that develop in oligodendrocytes, and more often in the oligodendrocytes that are found in the cerebral hemispheres. Oligodendrocytes are glial cells that produce myelin, a component of the brain that increases impulse speed. Oligodendrogliomas make up approximately 4% of primary brain tumors. Approximately 55% of all cases of oligodendrogliomas appear in people between the ages of 40 and 64.
- Ependymomas:
Ependymomas are tumors that develop in the ependymal cells. Ependymal cells are the cells in the brain and where ceribrospinal fluid (CSF) is created and stored. 24Ependymomas account for only 2% to 3% of all primary brain tumors but account for 8% to 10% of brain tumors in children. Ependymoma tumors are usually found in ventricle linings, the spinal cord, or the regions near the cerebellum.
Nongliomas are tumors that do not arise from glial cells. More prevalent examples of nongliomas include meningiomas and medulloblastomas. Less prevalent examples include medullpituitary adenomas, primary CNS lymphomas, and CNS germ cell tumors.
Meningiomas:
Meningiomas are tumors that develop in the meninges, membranes covering the brain and spinal cord. Meningioma tumors are frequently formed from arachnoid cells. These cells are responsible for the absorption of the cerebrospinal fluid (CSF). Meningioma tumors are responsible for 13% to 30% of all tumors arising within the cranium - the bony case surrounding the brain. Tumor arising within the cranium are also called intracranial tumors. Most meningiomas are benign. Malignant meningiomas are extremely rare, with an incidence rate of approximately two out of every million people, per year. The risk for developing meningiomas increases with age and is more prevalent in women.
Medulloblastomas:
Medulloblastomas are the most common brain malignancies in children. These cancers arise in the posterior fossa - a specific region of the space inside the skull (intracranial cavity) that contains the brainstem and the cerebellum. The fourth ventricle region is involved in the development of approximately 80% of childhood cases.
The Types of Brain Cancer Video :
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