Understanding the Different Types of Brain Tumors

Though there are over 150 different brain tumors, you don’t need to learn about all of them to get a solid understanding of the various types.

Our neurosurgeon, Richard B. Kim, MD, whittled the list down to the most common brain tumors and an explanation about how brain tumors are classified. Armed with this information, you’ll gain a broad understanding of all types of brain tumors.

Brain tumor classification

All the different types of brain tumors are either primary or metastatic. Beyond these two broad categories, tumors are further classified by the type of cells where the tumor started to grow and their location in your brain.

Primary tumors

Primary tumors originate in the brain and may be benign or malignant. These tumors are further classified as arising from glial or nonglial cells.

Nonglial cells make up structures such as the nerves, blood vessels, and glands. Glial cells are all the other brain cells. They have jobs supporting neurons, repairing damage, and producing cerebrospinal fluid, to name a few.

Metastatic tumors

Metastatic brain tumors spread from another part of your body to your brain. Up to 40% of people with lung cancer develop a metastatic brain tumor, for example. Breast cancer and melanoma, a type of skin cancer, also frequently spread to the brain.

Common types of benign brain tumors

This list includes the three most common benign primary brain tumors, meningiomas, schwannomas, and pituitary tumors:


The most common benign tumor, meningiomas originate in the meninges, which are the tissues surrounding your brain. Meningiomas can cause significant symptoms and disability as they grow and press against nerves and blood vessels.

Meningiomas may grow slowly or quickly. In rare cases, a meningiomas can turn into a malignant tumor.


Schwannomas grow in the nerve sheath, a membrane that insulates nerve cells. Over time, these tumors can displace the normal nerve tissue. The most common type of schwannoma, called an acoustic neuroma, affects nerves responsible for hearing and balance.

Pituitary adenomas

After meningiomas, schwannomas, and gliomas (the latter are malignant), pituitary adenomas are the most common brain tumors. Since these tumors grow on the pituitary gland, they may secrete hormones, causing a range of symptoms.

Malignant brain tumors

Gliomas represent 78% of all malignant brain tumors. All gliomas originate in glial cells. But they can begin growing in three different types of glia: astrocytes, ependymal cells, and oligodendroglial cells.

The most common types of gliomas include astrocytomas, glioblastomas, and ependymomas:


About half of all primary, malignant brain tumors are astrocytomas. They can develop in any part of your brain but they most often affect the cerebrum at the front of your brain, the cerebellum near the base, and the brain stem at the bottom of your brain. They can also develop in optic nerve pathways.


A glioblastoma develops in astrocytes, so these tumors are also called grade IV astrocytomas. Glioblastoma multiforme is the most common and deadliest brain tumor because it’s aggressive, grows quickly, and spreads rapidly.


As their name suggests, ependymomas originate in ependymal cells. These cells line the ventricular system, a group of cavities in the brain that produce and remove cerebrospinal fluid as it flows through the ventricles.

Brain tumors cause a range of symptoms. If you have questions about ongoing headaches, confusion, dizziness, difficulty concentrating, or changes in your sight or hearing, don’t wait to seek help. Call our office in Newport Beach, California, or book an appointment online.

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