Skip to main content

The Types of Brain Cancer


 

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.1 The World Health Organization (WHO) also assigns a grade from I to IV based on how aggressive the cells are.2

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.4 They are often named after the cells they resemble.5

A. Gliomas (The Most Common Type)

Gliomas arise from glial cells, the supportive cells of the brain.6 They are categorized by the specific type of glial cell they develop from:7

Type of GliomaOriginating CellCommon GradeKey Characteristics
Glioblastoma (GBM)Astrocytes (or mixed)Grade IV (Highest)The most common and most aggressive, malignant (cancerous) primary brain tumor in adults.
AstrocytomaAstrocytesGrade II, III, or IV (GBM)Can occur throughout the brain; often infiltrative (grow into surrounding tissue).
OligodendrogliomaOligodendrocytesGrade II or IIIArise from cells that produce myelin; often have specific genetic markers that can predict treatment response.
EpendymomaEpendymal cells (lining the ventricles)Grade I, II, or IIIMore 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 TypeOriginating TissueTypical NatureKey Characteristics
MeningiomaMeninges (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).
MedulloblastomaEmbryonal cells in the cerebellumMalignant (High Grade)Highly aggressive; one of the most common malignant brain tumors in children.
Pituitary AdenomaPituitary glandUsually BenignSlow-growing; can affect hormone production.
Schwannoma (Acoustic Neuroma/Vestibular Schwannoma)Schwann cells (on nerves)Usually BenignDevelops on the vestibular nerve (balance/hearing); slow-growing.
Primary CNS LymphomaLymphatic cellsMalignantA 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.9

  • 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:12

WHO GradeClassificationCharacteristics
Grade IBenign / Low-GradeSlowest growing; least malignant; often curable with surgery alone.
Grade IILow-GradeGrow slowly but may spread into nearby tissue; can potentially recur as a higher grade.
Grade IIIMalignant / High-GradeFaster growing; cells are abnormal (anaplastic); likely to recur.
Grade IVMalignant / High-GradeFastest 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. 

  1.     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.

  1.     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. 

  1.    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

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 :



Comments

Post a Comment

Popular posts from this blog

Your Brain and What It Does

Your Brain and What It Does Brain Information AMYGDALA : Lying deep in the center of the limbic emotional brain , this powerful structure, the size and shape of an almond, is constantly alert to the needs of basic survival including sex, emotional reactions such as anger and fear. Consequently it inspires aversive cues , such as sweaty palms , and has recently been associated with a range of mental conditions including depression to even autism. It is larger in male brains, often enlarged in the brains of sociopaths and it shrinks in the elderly. BRAIN STEM : The part of the brain that connects to the spinal cord . The brain stem controls functions basic to the survival of all animals, such as heart rate, breathing, digesting foods, and sleeping. It is the lowest, most primitive area of the human brain. CEREBELLUM : Two peach-size mounds of folded tissue located at the top of the brain stem, the cerebellum is the guru of skilled, coordinated movement (e.g., returning a tenn...
3 comments
Read more

The Limbic System

The Limbic System The Limbic System is a complex group of interconnected structures deep within the brain that is primarily involved in emotion, motivation, memory , and certain survival behaviors (like feeding, reproduction, and fight-or-flight responses ).2 It is often referred to as the emotional nervous system because of its profound influence on how we feel and react to the world. 3 🧠 Major Components and Functions While the exact components can vary slightly depending on the source, the core structures of the limbic system and their primary functions are: Structure Shape/Location Primary Role Amygdala Almond-shaped, near the hippocampus Processes emotions , especially fear and anger. Essential for forming memories tied to strong emotions (emotional valence). Hippocampus Seahorse-shaped structure Crucial for forming new long-term memories ( memory consolidation ) and spatial memory (navigation). Hypothalamus Sits below the thalamus Regulates the Autonomic Nervous System (he...
Post a Comment
Read more

HOW THE BRAIN CONTROL MOVEMENT

HOW THE BRAIN CONTROL MOVEMENT The brain controls movement through a complex, hierarchical system involving multiple regions that The brain controls voluntary movement through a precisely organized, hierarchical system that begins with intent and ends with the contraction of specific muscles. This is primarily executed via the motor pathways (descending tracts) involving several key brain regions. 🧠 Key Brain Regions for Movement Movement is not controlled by a single area, but by a network of structures that coordinate planning, initiation, execution, and correction. Cerebral Cortex (The Planner and Initiator): Premotor Cortex and Supplementary Motor Area : These areas in the frontal lobe are involved in the planning and sequencing of complex movements (e.g., deciding the steps to pick up a cup). Primary Motor Cortex (M1): Located in the frontal lobe's precentral gyrus , this is where the final, specific commands to initiate a voluntary movement are generated. It operates a...
Post a Comment
Read more