Chordoma
Chordomas are rare malignant tumors arising from embryonic remnants of the notochord in axial skeleton.
Epidemiology
They are predominantly found in adults, and comprise 0.2% of all central nervous system tumors and 2-4% of all primary bone neoplasms, with an estimated prevalence of 1 in 2 million people and a male-to-female ratio of 2:1.
Clinical description
The clinical presentation depends entirely on the location of the chordoma. The main possible locations are the sacrum, intracranially at the clivus and along the spinal axis. When the tumor is intracranial, the most common presenting symptoms are diplopia, swallowing problems and headache. Other neurologic signs also occur, primarily as cranial nerve palsies. Tumors in the spine can cause pain in the area of the tumor (neck, back or tailbone), as well as arm or leg pain, weakness or numbness, bladder and intestinal disturbances. Chordomas are characterized by slow growth, with local destruction of the bone and extension into the adjacent soft tissue. They can metastasize to lymph nodes, lungs, liver and bone.
Diagnostic methods
Diagnosis is made by radiography, computed tomography or magnetic resonance imaging.
Management and treatment
Treatment should be undertaken by expert neurosurgical and radiation oncology teams. Surgery is the primary mode of treatment but excision often remains incomplete despite repeat operations. Radiation in combination with surgery is then often used. High radiation doses (i.e. with proton beams) are required for local control. The role of chemotherapy or targeted therapies is still under investigation.
Prognosis
Prognosis depends on the extent and completeness of the tumor excision. Long-term follow-up is required because of the high rate of recurrence of these tumors.