by | Oct 19, 2018 | Uncategorized

If you or someone you love has been diagnosed with a brain tumor, the more you know about it, the better your understanding will be of what needs to be done to treat the condition.

A brain tumor is either a malignant (cancerous) or a benign (non-cancerous) mass or growth of abnormal cells that develop in the brain. Whereas most types of tumors and cancers are classified by stages, brain tumors are classified by grades.

How Are Brain Tumors Classified?

Brain tumors are determined by the degree of complexity of the tumor. Doctors classify brain tumors with the following grades:

  •  Grade I: The tissue is benign. The cells resemble normal brain cells and grow slowly.
  • Grade II: The tissue is malignant. The cells appear less normal than the cells in a Grade I tumor.
  • Grade III: The malignant tissue has cells that are clearly different from normal cells, and the abnormal cells are actively growing.
  •  Grade IV: The malignant tissue has cells that appear abnormal and are growing quickly.

Types of Brain Tumors

There are more than 120 types of brain and central nervous system (CNS) tumors. However, they can be classified into two general groups: primary (originating within the brain) and metastatic, or secondary (originating in another part of the body).

Primary brain tumors are categorized by the type of tissue in which they occur. The most common of these tumors are gliomas, which originate in the glial (supportive) cells.

There are several types of gliomas, including:


These form from small, star-shaped cells called astrocytes and can grow anywhere in the brain or spinal cord, but most often develop in the cerebrum. A grade III astrocytoma is sometimes called anaplastic astrocytoma. A grade IV astrocytoma is usually glioblastoma multiforme (GBM). Glioblastoma is the most common type of primary brain cancer.


These tumors begin in cells that produce myelin (for the central nervous system), the fatty covering that protects the brain and nerves, usually in the cerebrum. They are slow-growing and rarely spread into surrounding brain tissue.


These usually form in the lining of the ventricles or in the spinal cord. Ependymomas can develop at any age but are more common during childhood and adolescence.

Primary Brain Tumors That Are Not Gliomas

There are also other types of primary brain tumors that do not originate in glial cells. Among the most common are:


These grow from the meninges, which are the membranes that line the skull and vertebral canal and enclose the brain and spinal cord. Meningiomas are usually benign but grow quite large before causing any symptoms. Most often, they affect women between 30 and 50 years of age.


These are also benign tumors that develop from Schwann cells that produce myelin (for the peripheral nervous system). Schwannomas affect adult women twice as often as men.


These tumors develop in the pituitary gland near the hypothalamus. They’re usually benign but are considered malignant when they place pressure on or damage the hypothalamus, affecting vital functions.


Since these tumors occur in or around the pineal gland – which is a tiny organ located near the center of the brain – they are often too difficult to reach and cannot be removed. A pineocytoma is a slow-growing pineal tumor, and a pineoblastoma is a fast-growing tumor.

Metastatic brain tumors, which are caused by cancer that originates in another part of the body, are named for the original metastasizing (spreading) cancer. For example, lung cancer that spreads to the brain is referred to as metastatic lung cancer. That’s because the cells in the secondary brain tumor resemble abnormal lung cells rather than abnormal brain cells.

Cancer Treatment in Miami

If you or a loved one has been diagnosed with a benign or malignant brain tumor, The CyberKnife Center of Miami can treat your tumor using our advanced, image-guided robotic CyberKnife® System – which provides painless, noninvasive radiotherapy with few if any side effects.

Our dedicated staff would love to talk to you about your treatment options and help you on your journey to recovery. Call us at (800) 204-0455 or (305) 279-2900, or fill out our online form today to make an appointment. We look forward to hearing from you.