Oligodendrogliomas come from oligodendrocytes, one of the types of cells that make up the supportive, or glial, tissue of the brain. They can be low-grade (grade II) or high-grade (grade III, or anaplastic). Oligodendrogliomas are generally soft, grayish-pink tumors. They often contain mineral deposits (called calcifications), areas of hemorrhage, and/or cysts. Under the microscope, these tumor cells appear to have “short arms,” or a fried-egg shape. Sometimes oligodendrogliomas are mixed with other cell types.
These tumors can be found anywhere within the cerebral hemisphere of the brain, although the frontal and temporal lobes are the most common locations.
Because of their generally slow growth, oligodendrogliomas are often present for years before they are diagnosed. The most common symptoms are seizures, headaches, and personality changes. Other symptoms vary by location and size of the tumor.
Tumors of the frontal lobe may cause weakness on one side of the body, personality or behavior changes, and difficulty with short-term memory. Temporal lobe tumors are usually “silent,” causing few symptoms other than perhaps seizures or language problems.
If the tumor is accessible, standard treatment for oligodendroglioma is surgical removal of as much of the tumor tissue as possible. Biopsy is typically performed on tumors that are not accessible to confirm the diagnosis and determine the grade of tumor. Recurrent low-grade oligodendrogliomas can be treated with surgery, radiation therapy (if not given initially), and chemotherapy.
“Prognosis” is the medical term for a prediction of life expectancy. Keep in mind that these predictions are estimates. When your doctor talks with you about prognosis, s/he will take into account your age, the location of the tumor, grade of the tumor cells, whether your tumor has deletions of 1p and 19q, and the amount of tumor removed during surgery. Low-grade oligodendrogliomas tend to be slow growing tumors. Anaplastic oligodendrogliomas are more aggressive tumors which grow more quickly. Oligoastrocytoma growth generally depends on the percent of astrocytoma in the tumor, as astrocytomas tend to grow more rapidly than oligodendrogliomas. Scientists continue to study the impact of natural biologic differences amongst all of these tumors and the role of various treatment plans.
About 4% of primary brain tumors are oligodendrogliomas, representing about 10-15% of the gliomas. Only 6% of these tumors are found in infants and children. Most oligodendrogliomas occur in adults ages 50-60, and are found in men more often than women.Oligodendroglioma Brochure Oligodendroglioma Brochure | Spanish