Chondromyxoid fibroma, or CMF, is a tumor of the cartilage found between your bones. Cartilage is a rubber-like tissue that cushions and protects the ends of your bones, sits in between the disks in your spine, and makes up the ear and nose.

CMF tumors are benign, which means they are not cancer. While the cells of the CMF tumor do not travel to other parts of the body like cancer can, they can invade nearby tissues and can be painful and cause other symptoms.

CMF is a rare type of tumor, making up less than 1% of all bone tumors. It is usually found in older children and young adults. This type of tumor usually affects people between the ages of 10 and 30.

CMF is so rare, very little is known about what causes it to form. Scientists are always working to understand how tumors form, but it can be hard to prove.

We do not know if it runs in families because there are so few people with CMF.

CMF tumors can cause symptoms which include:

• Pain
• Swelling
• Stiffness
• Tenderness
• A growth or bump under the skin

Imaging:

If you have symptoms of CMF, your doctors will use imaging scans such as X-rays, CT, and MRI to look at where the tumor is and how big it is.

Biopsy:

To check if the tumor is CMF, your doctor will do a biopsy, taking a small sample from the tumor with a needle. An expert, called a pathologist, will study cells from the sample under the microscope to see what kind of tumor it is.

Treatment for each patient will be unique. Treatment options to discuss with your doctor include:

Surgery:

Once CMF is diagnosed, you may have surgery to remove the part of the bone with the tumor.

Cryotherapy:

Along with surgery, liquid nitrogen may be used to kill the tumor cells.

Phenol:

After surgery, phenol is a chemical which can be used to kill the remaining tumor cells.

The estimate of how a disease will affect you long-term is called prognosis. Every person is different and prognosis will depend on many factors, such as:

• Where the tumor is in your body
• How much of the tumor was taken out during surgery

If you want information on your prognosis, it is important to talk to your doctor. NCI also has resources to help you understand your prognosis.

Doctors estimate survival rates by how groups of people with CMF have done in the past. Because there are so few people with CMF, these rates may not be very accurate. They also can’t consider newer treatments being developed.

We know that surgery is a very effective treatment for CMF and that patients can live for many years. There is a 10 to 20% chance that CMF tumors may grow back, so it is important for patients to continue to see their doctors for follow-up care.