Chordoma is a rare form of tumor arising at the spine or base of skull. It grows out of remnant of notochord cells left over from fetal development of the spinal cord. Chordomas are not particularly metastatic (i.e., tending to go to other parts of the body), but the tumor may eventually grow to invade surrounding structures, including bone.
Approximately half of all chordomas occur at the spine, with the tailbone and the base of the skull serving as other common locations.
The notochord is a developmental structure that guides the boney growth and overall development of the spine. By around the sixth month of pregnancy, the baby's notochord has largely disappeared, although remnants may remain associated with the spine and skull base past birth and throughout life. These remnants are normally harmless, but may occasionally develop into a tumor: chordoma.
Chordomas are rare, with approximately one case diagnosed per million people. The incidence is split between men and women. Most patients harboring a chordoma are between 40 and 70 years of age at the time of diagnosis.
Because chordomas and chondrosarcomas arising from the skull base or spine are both tumors affecting the bones around the central nervous system, they tend to present with very similar symptoms. Neither tumor is particularly prone to metastasis, localizing most symptoms to the organs and structures surrounding the primary tumor. This makes the symptoms highly dependent on where the tumor is localized.
Tumors arising at the base of the skull typically present with one or more of the following signs/symptoms:
- Vision problems (such as double vision)
- Hearing loss
- Facial pain
- Difficulty swallowing
Tumors arising from the base of the spine present with symptoms separate from those arising from the skull base. Common signs/symptoms are:
- Lower-back pain
- Changes in bowel habits
- Impotence (in men)
- umbness in the lower back or extremities
- Changes in mobility (movement)
Symptom onset may be gradual (as with most low grade chordomas and chondrosarcomas) or relatively rapid (as with aggressive chordomas and chondrosarcomas).
The method of diagnosis for both chordomas and chondrosarcomas of the spine and skull base is similar. A physician will obtain a detailed medical history and perform a physical examination that may include a neurological evaluation in order to identify the tumor's location or to rule out alternative diagnoses.
Depending on your physician's findings, a variety of tests can be ordered to identify a possible chordoma/chondrosarcoma:
An x-ray in order to identify any boney abnormalities, such as a boney tumor.
A CT (computerized tomography) scan to image the affected bony area in more detail. A CT scan is a set of x-ray images compiled by a computer to form a series of 2-D pictures. Contrast dye may be used to highlight the tumor.
An MRI (magnetic resonance imaging) scan to exam the tumor and soft tissues in detail. Strong magnetic fields and radio waves produce better pictures of soft tissues than a CT scan. A contrast dye may be used to highlight the tumor.
A biopsy is to sample a section of the tumor for specific examination by a pathologist. A section of tumor may be removed with a needle, or it may be sectioned off by a surgeon attempting to remove the tumor. Tumor biopsy may often be performed when a chordoma or chondrosarcoma tumor is suspected. The biopsy allows for specific diagnosis of whether the tumor is a chordoma or chondrosarcoma, as well as a measure of how aggressively the tumor is growing (its malignancy).
Depending on what other structures are affected by the tumor, the physician may choose to order a variety of other laboratory or neurological tests to evaluate the patient's overall health and neurological function.
The course of treatment for a chordoma or chondrosarcoma of the spine or skull will depend on the tumor's size, location, and degree of spread, as well as the patient's age and overall health. Treatments include:
Surgery to remove as much of the tumor as possible is the preferred primary treatment. The ability of a surgeon to remove the tumor and the percentage of tumor he/she is able to remove will depend highly on the size and location of the growth. It may not be possible to totally excise tumors adjacent to or encapsulating certain nerves, blood vessels, or important parts of the brain/spinal cord.
For tumors located at the base of the skull, the surgeon may use a procedure known as the expanded endonasal trans-sphenoidal approach to access and remove the tumor through the nose (Please see the attached video.) Endoscopic methods (small cameras to see around the corners and maximize tumor removal) may be used. Other methods of surgical resection will depend on the tumor’s overall size, shape, and location.
The surgery will take approximately 2-6 hours based on the location and size of the tumor. After surgery, you will be observed in the intensive care unit overnight and then transferred to a private room the next day. There will be some discomfort in and around the nose but this is usually not very bothersome. You may be discharged from the hospital within a few days.
During surgery, if the tumor is invading or attached to the membranes around the brain (dura), a tear in these membranes in an attempt to remove the tumor may cause leakage of brain fluid (cerebrospinal fluid-CSF) from the nose after surgery. If this is the case, your hospitalization may be prolonged by a few days to allow the surgeon fix the leakage through a small tube placed in your back (lumbar drain) or a short second surgery to repair the leakage site. If the leakage is not corrected, the chance of infection (meningitis) increases.
Depending on the extent of your surgery, you may return to your daily activities shortly after discharge from the hospital. Any leakage of clear fluid from your nose should be reported to your surgeon.
Radiation therapy often follows surgical removal, but may also be used in instances of tumor recurrence or inoperable tumors. Radiation therapy is more often used to treat chordomas than chondrosarcomas.
There are several ways to administer radiation therapy. External-beam radiation involves high-energy radiation applied to the site of interest. Treatment usually occurs five times a week over the course of several weeks.
Stereotactic radiosurgery can apply higher doses of radiation to a smaller area. The radiation dose may be broken up over multiple beams. Using the radiological imaging data, your surgeon and radiation oncologist can deliver the radiation more precisely while avoiding healthy areas. It is an outpatient procedure, involves minimal anesthesia, and is usually done in one session.
All forms of radiation therapy carry some risk of damage to normal tissues. Specifics should be discussed with your radiation oncologist and surgeon.
Chemotherapeutic agents target the rapidly dividing cells of tumors and may rarely be used to treat chordomas or chondrosarcomas. These drugs also damage normal cells in the body that may frequently divide, resulting in side effects like hair loss and anemia.
The doctor may prescribe other medicines used to control or manage the symptoms associated with these tumors.
While tumor growth tends to be slow, the rate of recurrence for these tumors is high, and frequent follow-up observation is necessary to monitor for such recurrences.
University of Pittsburgh Medical Center Visit website
The Chordoma Foundation Visit website