Chordoma

Chordoma is a rare, malignant, slow-growing tumor that usually occurs along the spine, most often at the base and the tailbone, or at the base of the skull. It can spread to other organs like the lungs. Chordomas form from remnants of the notochord — embryonic tissue that eventually forms the center of spinal disks. They tend to grow slowly, beginning in the bones of the skull base or spine. They often cause problems with vision, hearing, balance and headaches.

Types & Stages 

Different types of chordoma include:

• Conventional chordoma. Also called classic chordoma and classical chordoma, this is the most common type. Under a microscope, it looks like bubbly cells in a slimy mix, similar to soap bubbles.
   
• Chondroid chordoma. Up to roughly 15 percent of chordomas are this type. Under a microscope, chondroid chordomas look similar to classic chordomas. But they also have tissue that looks similar to cartilage tissue found in parts of the body such as the nose.
   
• Dedifferentiated. Up to just under 10 percent of chordomas are this type. Under a microscope, this type of chordoma has two parts. One part looks like classic chordoma cells that also have a special protein called brachyury. The other part looks like a different type of cancer cell.
   
• Poorly differentiated. This rare type of chordoma mostly affects kids and young adults and is usually found in the skull base. It's identified due to a missing gene called SMARCB1 (INI1).

Signs & Symptoms 

Signs and symptoms of chordoma may differ depending on where the tumor is located and how large or advanced it is. But no matter where a chordoma is located, symptoms may include:

• Pain near the location of the tumor
• New nerve problems, such as numbness or weakness
• New changes to how and when you pass stool or urine

Signs and symptoms of a clival bone (bone that lies in a central position of the skull base) chordoma or a skull base chordoma may include:

• Headache
• Facial numbness, weakness, drooping or paralysis
• Vision trouble, including blurred or double vision or, sometimes, vision loss
• Hearing loss
• Hoarseness
• Trouble speaking as usual
• Trouble swallowing

Signs and symptoms of a chordoma in the part of the spine between the skull base and the sacrum (the triangular bone at the base of the spine) may include:

• Arm or leg numbness or weakness
• Back pain that may spread to the buttocks and legs
• Breathing trouble
• Headache
• Neck stiffness or pain
• Neck pain that may spread to the shoulders
• Swallowing trouble
• Walking trouble

Because chordomas grow very slowly and have general symptoms caused by many things, it's common not to notice signs and symptoms for years.

Diagnosis 

Tests and procedures to diagnose chordoma include:  

• Imaging tests. These may include:  
   
  • Computerized tomography scan (CT or CAT scan). A diagnostic imaging procedure that uses a combination of X-rays and computer technology to produce cross-sectional images (often called slices), both horizontally and vertically, of the body. CT scans are good at showing bone changes, such as holes or weak spots. On a CT scan, chordomas usually look like light or dark spots with damaged bone around them.  
     
  • Magnetic resonance imaging (MRI). MRI scans are better at showing tumors and the blood vessels around them. MRI scans can show if the tumor has different sections and how it's affecting the tissues around the spine. Chordomas usually appear as bright spots with darker areas inside them.
     
• Biopsy. A biopsy is a procedure to remove a sample of tissue for testing in a lab. A biopsy is essential to confirm whether what's seen on imaging is chordoma. That's because in imaging scans, chordoma can look like other conditions that need different treatments.  

Treatment 

Treatment for chordoma depends on the size and location of the cancer, as well as whether it has invaded nerves or other tissue. It includes:  

• Surgery. This is often the first step and an important chordoma treatment. If a tumor can be taken out fully, it offers the best chance at a cure. Types of surgery may differ depending on where the tumor is located:  
   
  • Skull base chordoma surgery. Sometimes surgeons can go through the nose to get to a skull base chordoma. This kind of surgery is called endoscopic skull base surgery. It uses a long, thin tube called an endoscope. The endoscope is inserted through the nose to access the tumor. Special tools can be passed through the endoscope to remove it.  
     
  • Traditional open surgery. During open surgery, a surgeon uses surgical instruments inserted through a large cut, also called an incision, at the back of the head or neck. Other approaches may also be used.
     
  • Mobile spine and sacral chordoma surgery. The goal of chordoma surgery in areas of the spine below the skull base is to take out as much of the tumor as possible. Other surrounding bone and tissues may also be removed. If the tumor is in the sacrum, at the bottom of the spine, the whole sacrum may be taken out. This is called a sacrectomy. This surgery may be done through an incision in the belly or in the back.
     
• Radiation therapy. Usually following surgery to kill any cancer cells that might remain. Sometimes radiation therapy is used before surgery to make a tumor smaller and easier to take out. It might be used by itself if it's not possible to take out the tumor through surgery.
   
• Targeted therapy. Medicines may be used for cancer that's spread in the body, called metastases, or for cancer that returns after initial treatment, called a recurrence.  

Causes & Risk Factors 

Factors that may increase the risk of chordoma include:

• Age. Chordoma can happen at any age. Most often, this cancer happens in people ages 40 to 60.
   
• Family history. Most chordomas happen randomly. But people with a family history of chordoma may have a greater chance of getting it. When this happens, it's because of changes in certain genes, such as the TBXT gene. This gene plays a role in making a protein called brachyury. Chordomas have a lot of brachyury in them. This can help tell chordomas apart from other tumors.
   
• Gender. In adults, males are somewhat more likely to be diagnosed with chordoma, accounting for about 60 percent of chordomas. In children, females are slightly more likely to be diagnosed with chordoma.

Screening 

There is no routine screening for chordoma.