Chordomas are rare malignant tumors that generally are formed in the spine (50%) or skull base (35%). Within the brain, they are located in the clivus which is a bone in the middle of the head.  Chordomas make up only 1% of all bone tumors, tend to occur in mid-age to older adults and occur in males twice as much as females. Because chordomas are malignanat, they are life-threatening and cause death by either growing directly and compressing nearby structures or by infecting other areas of the body, generally the lungs. 

Symptoms of a skull base (clival) chordoma tend to be varied. Because they grow so slowly, it is not uncommon for patients to have symptoms for over a year before they seek medical attention. Some symptoms of a chordoma to look for include headaches, neck pain, facial nerve palsy or facial muscle paralysis, and diplopia or double vision.

Diagnosing clival chordomas can require multiple approaches. By using computed tomography (CT) scanning, the amount of clival bone destruction and calcification can be assessed. While a magnetic resonance imaging (MRI) provides three dimensional analysis of the brain fluid and tissue. 

The treatment of chordomas is very difficult requiring a multi-staged approach. Since chemotherapy has not shown itself to be effective, radiation therapy is often used concurrently to surgery options. 

Surgical options include stereotactic radiosurgery and surgical resection. Unfortunately, aggressive surgery is required for a clean resection and a margin of normal brain tissue surrounding the chordoma must also be removed. This can lead to long term neurological impairment. However, with new skull base endoscopic and microneurosurgical techniques, less amount of surrounding tissue is disrupted and fewer amounts are required for marginal dissection. 

The prognosis for chordomas is better when treated early and aggressively. For patients who have surgery, 50% to 75% of them will be alive after five years with slightly lower numbers at ten years. Chordomas do tend to recur and even after multiple surgeries, once a recurrence happens the chance of survival is significantly reduced. Positively, clival chordomas have less than a 10% chance of metastasizing to another part of the body.