Giant Cell Tumors

A giant cell tumor (GCT) is a noncancerous growth. They don’t usually spread to other parts of your body, but they typically damage surrounding tissues. They often start in your bones or in the lining of your joints. To treat a GCT, your healthcare provider usually removes the growth with surgery.


What is a giant cell tumor?

A giant cell tumor (GCT) is a type of noncancerous (benign) growth (tumor). GCTs aren’t cancer, so they don’t usually spread to other parts of your body; although very rarely, they can spread to your lungs. But they may grow quickly and damage surrounding tissues, as they’re considered a locally aggressive tumor.

You may have a giant cell tumor at the end of one of your bones. These tumors often grow near your knee, either at the bottom of your thigh (femur) or the top of your shin (tibia). GCTs that grow in the soft tissues are called tenosynovial giant cell tumor (TGCT). TGCTs are also locally aggressive, but they’re even less likely to spread than GCTs.


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Is a giant cell tumor a sarcoma?

No. Both giant cell tumors and sarcomas are growths in your bones or soft tissues. Sarcomas are cancer, and GCTs aren’t.

Where do giant cell tumors get their name?

Giant cell tumors get their name because of how they look under a microscope. When viewed up close, giant cell tumors look like clusters of irregularly large cells.


Who might get a giant cell tumor?

GCTs of the bone are slightly more common in women. Younger people are also more likely to get giant cell tumors:

  • More than 1 in 2 people with a bone GCT are in their 30s or 40s.
  • Most people with a tenosynovial GCT are ages 25 to 50.

How common are giant cell tumors?

Giant cell tumors are rare. Experts estimate that each year about:

  • 1 in 1 million people get giant cell tumors of bone.
  • 43 in 1 million people get tenosynovial giant cell tumors.


Symptoms and Causes

What causes a giant cell tumor?

Giant cell tumors usually occur for no known reason. If you have a condition called hyperparathyroidism, you may be more likely to get multiple GCTs throughout your body.

TGCTs develop when there’s a change in your chromosomes. Chromosomes are the central part of your cell that contains DNA. Experts don’t know what causes the chromosome change that leads to TGCT.

What are the symptoms of a giant cell tumor?

Pain is the most common sign of a giant cell tumor in your bone. The pain may be mild at first, but usually worsens as the tumor grows. You may also have:

  • A noticeable bump or lump.
  • Pain that worsens with movement.
  • Swelling.
  • Fractures, as the GCT weakens the bone around it.

TGCT symptoms affect the joint where the growth is. Usually, the first sign of a TGCT is pain or swelling around one joint. You may also have:

  • Catching, locking or popping sensations.
  • Skin that feels tender or warm to the touch.
  • Stiffness.

Over time, your joint may feel unstable. Large TGCTs may cause your cartilage to wear away. Cartilage is the tissue that cushions and protects your bones. Over time, cartilage breakdown leads to arthritis.

Diagnosis and Tests

How is a giant cell tumor diagnosed?

Diagnostic tests, including radiology scans, help diagnose a giant cell tumor. Your healthcare provider may use:

  • Imaging tests, such as an X-ray, CT scan or MRI, look at your bone or cartilage.
  • Bone scans use a safe radioactive dye and imaging scans to look for a bone GCT.
  • Biopsy, takes a small tissue sample to examine in a lab for signs of a GCT.

Management and Treatment

How is a giant cell tumor treated?

Usually, healthcare providers treat both bone and tenosynovial giant cell tumors with surgery:

  • To treat bone GCTs, your healthcare provider scrapes the tumor away from your bone (curettage). Then, they fill the bone in with another piece of bone or a bone cement mixture (bone graft). When tumors are very big, your doctor may prescribe medications, followed by resection (removal) of the bone segment and reconstruction with a prosthesis.
  • To treat TGCTs, your healthcare provider removes the tissue lining in your joint where the TGCT is.

If your healthcare provider can’t safely remove the entire tumor with surgery, you may have nonsurgical treatments, such as:

  • Embolization blocks the blood vessels that send blood to the tumor so the tumor starts to die.
  • Medication may target certain parts of the cells in a bone GCT to slow down tumor growth and prevent your bones from breaking down.


How can I prevent a giant cell tumor?

Experts don’t know what causes giant cell tumors, so there’s no way to prevent them. If you notice pain, swelling or a lump around one of your bones or joints, see your healthcare provider. GCTs are often easier to treat when they’re found early.

Outlook / Prognosis

What is the outlook for giant cell tumors?

The outlook for a giant cell tumor varies depending on the tumor size, location and your overall health. After treatment, you’ll have regular follow-up appointments with your healthcare provider. If the tumor comes back, these visits increase the chances of finding and treating it early.

Is a giant cell tumor life-threatening?

Giant cell tumors are rarely life-threatening. But they can damage your bones and tissues. If you have any signs of a giant cell tumor, it’s important to see your healthcare provider right away. If available to you, you may wish to see an orthopaedic oncologist, who specializes in bone cancer.

Living With

What else should I ask my provider?

You might want to ask your healthcare provider:

  • What type of giant cell tumor do I have?
  • What tests do I need to diagnose a giant cell tumor?
  • What are my treatment options?
  • What are the chances that a giant cell tumor will come back after treatment?
  • Is there anything I can do to reduce the risk of a GCT coming back?

A note from Cleveland Clinic

Giant cell tumors (GCTs) are noncancerous growths. They commonly start in your bones or in the tissues that surround your joints. Although GCTs aren’t cancer, they can damage your bones and tissues. You may have pain, swelling, stiffness or catching sensations when you move. Usually, GCT treatment involves surgery to remove the growth.

Medically Reviewed

Last reviewed on 02/10/2022.

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