Glioblastoma Multiforme (GBM)

What Is It?

Glioblastoma multiforme, also known as malignant glioma or a grade IV glioma, is a tumor that arises within the brain or spinal cord and is derived from glial cells. Glial cells can be though of as "helper" cells in the nervous system. They help keep conditions normal so that the nerve cells can function properly. However, when they give rise to a tumor, these tumors are termed Gliomas. GBM is unfortunately one of the most malignant and aggressive tumors that occur in the human body.

GBM, rather than being a completely different type of glioma, is actually just a severe, aggressive form of other glioma tumors. For example, both oligodendroglioma and astrocytomas, if very malignant, can be considered a glioblastoma multiforme. They can occur throughout the brain and spinal cord. They generally have no known cause. However, while some GBMs develop from previously diagnosed lower-grade tumors, some appear to occur spontaneously.

Gliomas are generally graded depending on their level of aggressiveness. They can vary from more benign tumors ("low grade") to more malignant ("high grade"). Generally, benign tumors are more slow growing and less invasive and destructive to normal brain tissue while more malignant tumors grow quickly, invade tissue and are more destructive. All of these tumors are graded on a 4-point scale as either grade I, grade II, grade III or grade IV. Grade I tumors are the most benign and Grade IV tumors are the most malignant.

Grade IV tumors, the most malignant variety of gliomas, are also known as glioblastoma multiforme. Some astrocytomas or oligodendrogliomas which were previously a lower grade, can become more malignant and eventually become a GBM. Some GBMs appear sporadically and seem to first present as a GBM without going through a lower grade tumor stage first.

What Types of Symptoms Are Typical?

As for any glioma, the presenting symptoms can vary greatly depending on its size and location. While glioblastomas are generally very quickly growing, they can present with very different symptoms depending on where they occur. Just about any neurological symptom is possible including, but not limited to, weakness, numbness, visual changes, memory loss, etc. This varies considerably from patient to patient.

Any mass in the head can cause pressure that can lead to headaches, nausea and vomiting. Another common symptom is seizure.

How Is The Diagnosis Typically Made?

Generally, after a general neurological examination, additional testing is required to diagnose glioblastoma. Some form of imaging, either CT scan or MRI scan with contrast dye, is used to get a picture inside the head and brain. These studies are generally very effective in detecting a brain tumor and defining its size and location.

However, the definitive diagnosis of GBM cannot be made until some tissue is collected to be studied by a pathologist. This tissue is usually either obtained by a biopsy or a larger operation.

What Are Some Common Treatments?

As with all gliomas, the treatment plan varies considerably from patient to patient depending on the specifics of each tumor. In general, because glioblastoma is so aggressive and malignant, aggressive treatment strategies, often using surgery, radiation treatments and/or chemotherapy are employed. However, the treatment plan, of course, is determined by the patient and their personal physician and varies depending on many factors.

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Important Note: This site is not intended to offer medical advice. Every patient is different, and only your personal physician can help to counsel you about what is best for your situation. What we offer is general reference information about various disorders and treatments for your education.

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