A malignant glioma is a type of cancerous brain tumor. There are two main categories of brain tumors: primary and secondary. Secondary brain tumors are cancers that started in another part of the body and spread to the brain. Primary brain tumors, which are less common, start developing in the patient’s brain tissue. Gliomas are primary brain tumors that develop from glial cells, which are cells that support the brain and help to maintain and repair the nervous system.
A tumor, no matter where it develops in the body, is simply a mass of abnormal cells. Sometimes tumors are not cancerous and are refereed to as benign tumors. Those that are cancerous are called malignant tumors, and gliomas can be either benign or malignant. Unfortunately, malignant gliomas can be deadly. They can also spread and grow, though they usually spread within a person’s nervous system and do not move to other parts of the body.
Glial cells are the most common brain cells. When compared to neurons, which are nerve cells, they are far more prevalent. In fact, there are at least five glial cells for every one neuron in the brain. The main types of glial cells include astrocytes, which are typically found in the cerebrum; ependymal cells, which are cells that line the area of the brain in which cerebrospinal fluid is produced; and oligodendrocytes, which support cells responsible for nerve impulse transmission.
The brain cells that are called neurons do not have the ability to divide and multiply; glial cells, however, do have this ability. As such, they may sometimes divide too rapidly and create a brain tumor. Most gliomas form in the astrocytes and are referred to as astrocytomas. The tumors that form in the oligodendrocytes are called oligodendrogliomas, while those that form from ependymal cells are called ependymomas—both of these types occur less frequently than astrocytomas.
Just as there are different types of malignant glioma cases, there are also different speeds at which gliomas may grow. Some are called low-grade gliomas because they grow very slowly, while others are called high-grade and grow quickly. Thousands of people are diagnosed with gliomas every year.
A malignant glioma presents a treatment challenge. Treatment options depend on the type of malignant glioma a person has and how much it has spread. One treatment method is surgical removal of the tumor and chemotherapy once the tumor is gone. Radiation treatment may be used as well, but carries the risk of damaging healthy cells while killing the cancer. Unfortunately, some malignant gliomas return, even after successful treatment.