Because there are many varieties of glioma, they are often differentiated by cell type, grade, or location. The cells of the glioma share certain histological characteristics with other cells. These similarities allow clinicians to identify four main types of glioma. The type of cell they resemble is not necessarily the cell where the glioma originates—it simply denotes a resemblance.
Type of Glioma
Cells It Resembles
Astrocytomas, including glioblastoma multiforme
Mixed gliomas, including oligoastrocytomas
Gliomas can also be graded. The World Health Organization (WHO) grades gliomas on a scale of I (least advanced) to IV (most advanced). A low-grade glioma (WHO grades I and II) has cells that are well-differentiated from each other (not anaplastic*).
Physicians also distinguish gliomas based on their location. Gliomas most frequently occur in the brain.
The causes of gliomas are not known. Some hereditary factors have been implicated since neurofibromatoses, and tuberous sclerosis complex (genetic disorders) have been associated with increased risk of gliomas.
Since glioma is a broad term for a variety of different tumors, symptoms vary depending on the type, location, and grade of the tumor. Brain gliomas typically produce symptoms of headache, nausea and vomiting, seizures, and disorders related to increasing intracranial pressure. In some instances, a glioma may produce other symptoms such as vision loss (if it is near the optic nerve) or pain or weakness in the extremities (if it is in the spinal cord).
At the Piedmont Brain Tumor Center, diagnosis is made after a thorough physical examination, neurological study, and patient history has been conducted. In most instances, the presence and location of the tumor will be determined by a computed tomography (CT) or magnetic resonance imaging (MRI) scan. In some cases, it may be important to obtain a biopsy of the tumor tissue to help diagnose it. A biopsy involves surgically removing a tiny amount of the tumor for laboratory analysis.
An important aspect in diagnosing glioma is identifying the type, location, and grade of the glioma.
Since there are many types of glioma, treatment options for glioma are varied. At the Piedmont Brain Tumor Center, your physician will discuss the type of tumor and treatment options. Treatment for gliomas often involves combination therapy, including surgery, radiation, and chemotherapy. However, in some low-grade gliomas, intensive medical monitoring may be required with no surgery. There are currently some new drugs being studied that may be useful in fighting gliomas.
Glioma is actually a broad general term for a tumor originating in the glial cells and encompasses many types of tumors, most of which occur in the brain. Gliomas can be categorized by cell type, grade, and location. Accurate diagnosis of glioma includes a precise identification of the type of tumor as well as its grade and location. High-grade gliomas (WHO grades III and IV) are more advanced and tend to be invasive. There are several treatment options for glioma, which will vary depending on the individual patient. Most frequently, gliomas are treated with combination therapy (surgery, chemotherapy, radiation).
*Anaplastic cells that divide rapidly and have no resemblance to normal cells.