Giant cell tumor of bone is a rare, fast-growing noncancerous tumor. It most often grows in adults between ages 20 and 40 when skeletal bone growth is done. It is slightly more common in women.

It often grows near a joint at the end of the bone. The location of a giant cell tumor is often in the knee but can also grow in the bones of the arms and the legs. It can also affect the flat bones, such as the breastbone or pelvis.

The exact cause of giant cell tumors is not known. But in some cases, they have been linked to Paget disease of bone. This is a long-term (chronic) bone disorder in which bones become enlarged and misshapen.

Symptoms can be different for each person. Symptoms may include:

• A visible bump
• Bone break (fracture)
• Fluid buildup in the joint nearest the affected bone
• Limited movement in the nearest joint
• Swelling
• Pain at the nearest joint

Some of these symptoms may be caused by other health problems. Always talk with your doctor for a diagnosis.

Your doctor will ask about your health history and give you a physical exam. You may also have tests, such as:

• Biopsy. A small sample of tissue is taken and tested. This is often needed to confirm diagnosis.
• Radionuclide bone scan. This is a nuclear imaging test. It can show any degenerative or arthritic changes in the joints, find bone diseases and tumors, and find the cause of bone pain or inflammation. This test helps to rule out any infection or fractures.
• X-ray. This test uses a small amount of radiation to make images of tissues, bones, and organs on film.
• CT scan. This test uses a series of X-rays and a computer to make detailed images of the tissues in the body.
• MRI. This is a test that uses large magnets, radio waves, and a computer to make detailed images of tissues in the body. This test can also rule out any problems of the spinal cord and nerves.

Treatment will depend on your symptoms, age, and general health. It will also depend on how severe the condition is.

The goal for treatment of a giant cell tumor is to remove the tumor and prevent bone damage. Treatment may include:

• Surgery to remove the tumor and any damaged bone
• Bone grafting
• Bone reconstruction
• Physical therapy to regain strength and mobility
• Amputation, in severe cases

Tumors that can't be removed with surgery can often be controlled and sometimes destroyed with radiation therapy.

Giant cell tumors can come back. Follow-up with your doctor may be needed for several years.

• A giant cell tumor is a rare, aggressive, noncancerous tumor. It often grows near a joint at the end of the bone. Most occur in the long bones of the legs and arms.
• They most often occur in adults between ages 20 and 40, when skeletal bone growth is complete.
• Symptoms may include joint pain, swelling, and limited movement.
• The goal for treatment of a giant cell tumor is often to remove the tumor and prevent damage to the affected bone.
• Tumors that can't be removed surgically can often be controlled and sometimes destroyed with radiation therapy.
• Giant cell tumors can come back.

Tips to help you get the most from a visit to your doctor:

• Know the reason for your visit and what you want to happen.
• Before your visit, write down questions you want answered.
• Bring someone with you to help you ask questions and remember what your doctor tells you.
• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your doctor gives you.
• Know why a new medicine or treatment is prescribed and how it will help you. Also know what the side effects are.
• Ask if your condition can be treated in other ways.
• Know why a test or procedure is recommended and what the results could mean.
• Know what to expect if you do not take the medicine or have the test or procedure.
• If you have a follow-up appointment, write down the date, time, and purpose for that visit.
• Know how you can contact your doctor if you have questions, especially after office hours, and on weekends and holidays.