Chordoma
Definition
Chordomas are a type of primary bone malignancy usually found in the skull or spine. These tumors are rare and slow growing, accounting for only one percent of cancers of the central nervous system. These tumors develop from remnants of notochord, which precedes the spinal column during embryonic development. While chordomas may be found at any site along the axial skeleton, they are most frequently found at the sacrum (base of the spine), the coccyx (tailbone), and at the clivus (base of the skull).
Chordomas rarely metastasize, but are locally aggressive and affect adjacent organs, tissues, and bone. This type of tumor has a high reoccurrence rate.
These types of tumors are most commonly found in patients ranging in age from 40 to 70.
Causes
While the cause of primary bone tumors is unknown, chordomas are thought to develop from leftover pieces of notochord that did not break down after birth. Over many years, these harmless bits of notochord may transform and become cancerous, forming chordomas.
Risk Factors
There are no known risk factors associated with chordomas. They are thought to develop spontaneously. Chordomas are not known to be caused by environmental factors, trauma, or diet, and are not associated with any medical conditions.
Symptoms
Symptoms often develop gradually and vary depending on the size and location of the tumor.
These may include:
- back pain
- changes in bowel habit
- incontinence
- impotence
- numbness
- changes in mobility (movement)
- headache
- double vision
- facial pain
- changes in hearing
- difficulty swallowing
Symptoms are dependant on the location of the tumor. Patients with tumors located near the sacrum may experience pain in their back and lower extremities, while patients with intracranial chordomas often present with double vision and headaches.
Diagnosis
In addition to a physical exam, your physician may request one or more of the following tests to confirm diagnosis:
- Computed Tomography (CT scan): A computerized x-ray machine is used to take a series of detailed pictures from many different angles. Dye may be injected to help to clarify organs and tissues.
- Magnetic Resonance Imaging (MRI): Powerful magnet waves are used to make a series of detailed pictures. Patients are injected with a substance called gadolinium to highlight possible cancer cells.
- Biopsy: Biopsies of chordomas are useful when the results of imaging studies don’t allow for positive identification. Fine needle aspiration (FNA) is the preferred method, and has been reported to lower local recurrence rates when compared with open biopsy.
Treatment
There are three standard treatments that are used: surgery, chemotherapy, and radiation therapy. Your physician may recommend one or a combination of these treatments.
Surgery: Surgery is the main modality of treatment for chordomas. The type of procedure depends on the size and location of the tumor. Today there are a variety of minimally invasive surgical options allowing surgeons to access areas previously impossible to reach.
Chordomas of the skull base can be directly approached through expanded endonasal approach(EEA). this state-of-the-art, minimally invasive surgical procedure uses the nose as a natural corridor to reach these lesions. There are no incisions in the skin of the face or head. After an expanded endonasal resection of the tumor, patients do not need to wait several weeks to heal from the surgery before any radiotherapy is performed. Patients can receive radiation treatment sooner when indicated.
Radiation: Radiation therapy may be delivered externally by directing radiation at the tumor from an outside source, internally by placing radioactive material directly in the body near the cancer, or using stereotactic radiosurgery to deliver a concentrated dose of radiation directly to the brain tumor. This procedure requires the use of special immobilizing equipment and MRI or CT scans to guide the radiation.
Chemotherapy: Chemotherapy uses drugs to stop the growth of cancer cells. Depending on the type and stage of the cancer, chemotherapy may be taken by mouth, as an injection, or placed directly into the tumor site.
Clinical trials are an important component of care for patients with cancer, and participation in clinical trials may offer additional treatment options. Ask your physician if a clinical trial may be right for you.
Frequent follow up is required because of the high rate of recurrence of these tumors.
Prevention
There are no guidelines for prevention. Early diagnosis may prevent serious complications.