About skull base chordoma
What is skull base chordoma?
Chordomas are very rare primary bone tumors that can arise at almost any point along the axis of the spine from the base of the skull to the sacrum and coccyx (tailbone). The incidence of chordoma in the general U.S. population is about 8 per 10,000,000 people. They occur somewhat more often in males than females and, for unknown reasons, are rare in African Americans. Under the microscope, chordoma cells appear to be benign, but because of their location, invasive nature, and recurrence rate, the tumors are considered to be malignant. They arise from cellular remnants of the primitive notochord, which is present in the early embryo. In normal mammalian development, the notochord and substances produced by it are involved in forming the tissues that give rise to vertebrae. Normally, the tissues derived from the notochord disappear after the vertebral bodies have begun forming. However, in a small percentage of people, some tissues from the notochord do not disappear. Rarely, these leftover tissues give rise to chordomas.
About one-third of chordomas are found in the region around the clivus. The clivus is a bone in the base of the skull. It is located in front of the brainstem and behind the back of the throat (nasopharynx). Chordomas occur with equal frequency in the skull base, the vertebrae and the sacrococcygeal area towards the bottom of the spine.
Symptoms of the presence of chordomas vary with their location and size. Most chordomas occur randomly among the population (sporadic). However, some people develop this tumor as a result of a mutation inherited as an autosomal dominant trait.
What are the symptoms for skull base chordoma?
What are the causes for skull base chordoma?
The spinal cord is housed within a hollow chamber within the vertebrae (spinal canal). It extends from the base of the skull to the lower back.
It's not clear why most spinal tumors develop. Experts suspect that defective genes play a role. But it's usually not known whether such genetic defects are inherited or simply develop over time. They might be caused by something in the environment, such as exposure to certain chemicals. In some cases, however, spinal cord tumors are linked to known inherited syndromes, such as neurofibromatosis 2 and von Hippel-Lindau disease.
What are the treatments for skull base chordoma?
Ideally, the goal of spinal tumor treatment is to eliminate the tumor completely, but this goal may be complicated by the risk of permanent damage to the spinal cord and surrounding nerves. Doctors also must take into account your age and overall health. The type of tumor and whether it arises from the structures of the spine or spinal canal or has spread to your spine from elsewhere in your body also must be considered in determining a treatment plan.
Using microsurgical techniques, a tumor is gently teased out of the spinal cord in the cervical spine.
Treatment options for most spinal tumors include:
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Monitoring. Some spinal tumors may be discovered before they cause symptoms — often when you're being evaluated for another condition. If small tumors aren't growing or pressing on surrounding tissues, watching them carefully may be all that's needed.
During observation, your doctor will likely recommend periodic CT or MRI scans at an appropriate interval to monitor the tumor.
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Surgery.This is often the treatment of choice for tumors that can be removed with an acceptable risk of spinal cord or nerve injury damage.
Newer techniques and instruments allow neurosurgeons to reach tumors that were once considered inaccessible. The high-powered microscopes used in microsurgery make it easier to distinguish tumor from healthy tissue.
Doctors also can monitor the function of the spinal cord and other important nerves during surgery, thus minimizing the chance of injuring them. In some instances, very high-frequency sound waves might be used during surgery to break up tumors and remove the fragments.
But even with the latest technological advances in surgery, not all tumors can be totally removed. When the tumor can't be removed completely, surgery may be followed by radiation therapy or chemotherapy or both.
Recovery from spinal surgery may take weeks or longer, depending on the procedure. You may experience a temporary loss of sensation or other complications, including bleeding and damage to nerve tissue.
Pediatric neurosurgery consultation
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Radiation therapy. This may be used to eliminate the remnants of tumors that remain after surgery, to treat inoperable tumors or to treat those tumors where surgery is too risky.
Medications may help ease some of the side effects of radiation, such as nausea and vomiting.
Sometimes, your radiation therapy regimen may be adjusted to help minimize the amount of healthy tissue that's damaged and to make the treatment more effective. Modifications may range from simply changing the dosage of radiation to using sophisticated techniques such as 3-D conformal radiation therapy.
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Chemotherapy. A standard treatment for many types of cancer, chemotherapy uses medications to destroy cancer cells or stop them from growing. Your doctor can determine whether chemotherapy might be beneficial for you, either alone or in combination with radiation therapy.
Side effects may include fatigue, nausea, vomiting, increased risk of infection and hair loss.
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Other drugs. Because surgery and radiation therapy as well as tumors themselves can cause inflammation inside the spinal cord, doctors sometimes prescribe corticosteroids to reduce the swelling, either after surgery or during radiation treatments.
Although corticosteroids reduce inflammation, they are usually used only for short periods to avoid serious side effects such as muscle weakness, osteoporosis, high blood pressure, diabetes and an increased susceptibility to infection.
What are the risk factors for skull base chordoma?
The exact cause of skull base chordoma is not known, but it's thought to be related to changes in cells called mesenchymal stem cells. These are found in many different tissues throughout the body, including bone marrow, cartilage, and fat tissue.
- Age: Your risk increases as you get older.
- Gender: Men are more likely than women to develop this tumor.
- Family history: People with a family history of skull base tumors have an increased risk of developing this condition.
- Past radiation therapy to the head and neck
- Previous surgery on the head, neck, or spine