Tenosynovial Giant Cell Tumor

Medically Reviewed By William C. Lloyd III, MD, FACS
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What is a tenosynovial giant cell tumor?

Tenosynovial giant cell tumors (TGCTs) are benign and rare. However, even though they are not cancerous, these tumors can cause problems ranging from mild discomfort to severe disability.

TGCTs are a group of tumors that can affect three types of bodily tissues:

  • Synovium. Also called stratum synoviale or synovial stratum, this soft membrane protects the inside of joint spaces. It also covers the bursae and tendon sheaths.

  • Bursae. These fluid-filled sacs provide cushioning around the joints so bones don’t grind together when you bend the joint.

  • Tendon sheath. This membrane protects the fibrous connective tissue, the tendon, that attaches your muscles to your bones. 

TGCTs can affect anyone, though they are rare in children. Females have a slightly higher chance of developing a TGCT, but no other risk factors have been found.

Symptoms of tenosynovial giant cell tumors, such as pain, swelling and stiffness, develop gradually and often get worse with time.

Surgery to remove the TGCT is the main course of treatment, but it’s not always successful because the tumor can return. One oral medication has been approved to treat tenosynovial giant cell tumors for certain people.

Without treatment, tenosynovial giant cell tumors can grow larger, increasing pain and decreasing range of motion. TGCTs are not life-threatening, but they can significantly reduce a person’s quality of life. Joint damage can affect the ability to do everyday activities.

What are the different types of tenosynovial giant cell tumor?

Sometimes called subtypes, there are two kinds of tenosynovial giant cell tumors. The type depends on how much of the joint the tumor affects. These two tenosynovial giant cell tumor types include:

Localized-type tenosynovial giant cell tumors. In the past, this type of tumor was called a giant cell tumor of the tendon sheath. Localized-type tenosynovial giant cell tumors:

  • Usually affect smaller joints, such as the fingers or wrist

  • Affect only a small part of the joint

  • Usually do not cause significant, permanent damage to the joint

  • Are less likely to recur

Diffuse-type tenosynovial giant cell tumors. Formerly, this was called nodular tenosynovitis and pigmented villonodular synovitis. Diffuse-type tenosynovial giant cell tumors:

  • Typically affects large joints, such as the knee or hip

  • Are aggressive

  • Affect the entire joint

  • Can cause debilitating joint damage without treatment

  • Are more likely to come back 

Worldwide, localized-type tenosynovial giant cell tumors are more prevalent than diffuse-type tenosynovial giant cell tumors.

What are the symptoms of a tenosynovial giant cell tumor?

While tenosynovial giant cell tumors (TGCTs) are not cancer, they still may cause damage to the tissues as they grow. Depending on the type of TGCT, symptoms may vary. They usually get worse with time.

Common symptoms of a tenosynovial giant cell tumor

The most common TGCT symptoms and signs include:

  • Inflammation (swelling)

  • Joint movement limitations

  • Mass visible under the skin

  • Pain and tenderness

  • Stiffness

  • Warmth

These symptoms can affect any joint in the body, both small and large joints. In both diffuse and localized TGCTs, some people may first notice swelling at the joint without pain, and the affected area may gradually become painful.

Serious symptoms of a tenosynovial giant cell tumor

A tenosynovial giant cell tumor is not life-threatening. However, it can still cause significant damage to bones and joints, resulting in degeneration of the joint and sometimes disability. Serious tenosynovial giant cell tumor symptoms involve increasing severity of pain, swelling and problems moving the joint.

Some types of TGCTs are less likely to cause disability if they are treated promptly.

What causes a tenosynovial giant cell tumor?

A tenosynovial giant cell tumor is a genetic condition. Changes on parts of chromosomes 1 and 2 cause the body to make too much colony stimulating factor-1 (CSF-1) protein. Cells that overproduce this protein attract other cells in the body that have a CSF-1 receptor. As a result, these cells, which are typically a certain type of white blood cell, bind together. When these cells continue to attract and bind with other cells, they develop into a tenosynovial giant cell tumor.

While scientists know that the tumors are caused by chromosomal changes, they don’t know what causes those genetic changes to happen. They have not found any external cause, such as lifestyle habits or environmental triggers, that makes these changes occur.

What are the risk factors for a tenosynovial giant cell tumor?

Tenosynovial giant cell tumors (TGCTs) are rare and seem to have very little propensity for any given demographic. They can develop in anyone of any age, from young children to seniors.

Most people with these types of tumors are diagnosed between ages 25 and 50—it’s very rare that a tenosynovial giant cell tumor occurs in someone younger than 10 or older than 60. Females are slightly more likely than males to develop a tenosynovial giant cell tumor.

Contact your doctor if you experience any persistent symptoms that affect your joints. With an accurate diagnosis and appropriate treatment, you may avoid more serious joint problems later.

What are some conditions related to tenosynovial giant cell tumors?

Tenosynovial giant cell tumors can present symptoms similar to other, potentially more serious medical conditions.

Conditions with similar symptoms to tenosynovial giant cell tumors include:

  • Synovial hemangiomas

  • Synovial chondromatosis 

  • Sports injuries 

  • Fibromas

  • Ganglion cysts 

  • Malignant sarcomas

How do doctors diagnose a tenosynovial giant cell tumor?

Your doctor will conduct a physical exam and gather information about your symptoms and medical history. However, symptoms alone will not provide enough evidence for a diagnosis of a tenosynovial giant cell tumor (TGCT) Your doctor will want to do some tests to rule out other conditions.

Tests may include:

  • X-rays, which can show joint damage

  • MRI (magnetic resonance imaging), which can reveal blood vessels and other changes related to tumor growth 

  • Bone scan, which can detect bone diseases 

  • Synovial fluid sample

  • Biopsy, to rule out cancer

In many cases, the MRI can provide the information the doctor needs to diagnose the tumor, determine the type of TGCT, and develop a treatment plan.

What are the treatments for a tenosynovial giant cell tumor?

If a patient has only mild symptoms, doctors may recommend a wait-and-see approach, since tenosynovial giant cell tumors (TGCTs) are not cancerous and treatment is not urgent. Treatment may be necessary if symptoms worsen. Surgical removal is the standard tenosynovial giant cell tumor treatment, though one oral treatment is available. It has been shown to be effective in some people.


Surgery typically has varying success depending on the type of TGCT.

Surgical removal of a localized tumor is often curative, with a lower chance of tumor recurrence compared to surgical removal of a diffuse tumor.

Diffuse-type tenosynovial giant cell tumors have a 50% or higher chance of coming back, even after multiple surgeries to remove them.

Radiation therapy

If the surgeon cannot remove the entire tumor, they may recommend radiation therapy after surgery. Radiotherapy may be particularly useful if the tumor comes back. However, the complete risks of radiation for a tenosynovial giant cell tumor are not fully understood.


One systemic treatment has FDA approval for adults with TGCT and severe movement problems. The medication, oral pexidartinib capsules, may be an option for people with a TGCT that does not improve with surgery or who cannot have surgery for other health reasons. People may need to take this medication for several months before noticing improvement, and the treatment does not work for everyone.

This medication comes with some side effects, with the potential for severe, life-threatening liver injury. Your doctor will closely monitor your liver function Some people have to stop taking this medication if damage occurs. Other side effects of pexidartinib include changes in hair color, higher cholesterol, and rash.

How does a tenosynovial giant cell tumor affect quality of life?

The movement limitations that tenosynovial giant cell tumors cause often create significant decreases in health-related quality of life, affecting a person’s ability to work, play sports, and do everyday activities. Pain and stiffness make some activities difficult or impossible, depending on the severity of the symptom. After treatment, many people experience less pain and swelling, but some may actually have increased stiffness and reduced movement.

People with a diffuse-type tenosynovial giant cell tumor typically experience a higher negative impact on their quality of life compared to a localized tumor. Treatment is less likely to work or the tumor recurs after treatment. People with tenosynovial giant cell tumors often have higher healthcare costs, including the cost of physical therapy.

A TGCT can become a chronic condition. Some people may find it helpful to participate in a support group for people with tenosynovial giant cell tumors. You can exchange thoughts, feelings and coping strategies with people who may share similar experiences. Talk with your doctor or a member of your care team for resources. Since TGCTs are rare, the support group may meet online instead of in person.

What are the potential complications of a tenosynovial giant cell tumor?

Left untreated, a tenosynovial giant cell tumor (TGCT) can cause significant physical disability. Particularly in larger joints, such as the hip, deterioration of the joint is typically how the TGCT progresses. When the tumor affects the knee, many people need knee replacement surgery.

Even with surgical removal of the tumor, many patients eventually develop osteoarthritis.

Amputation may be needed in severe cases of TGCT, but this is rare.

What is the survival rate and prognosis for a tenosynovial giant cell tumor?

Both localized-type and diffuse-type tenosynovial giant cell tumors (TGCTs) are benign (not cancerous) and not life-threatening. However, for some people, physical disability can be severe. Even after surgery, a significant number of people have a recurrence of the TGCT, particularly diffuse-type TGCTs.

If you are diagnosed with a TGCT, work closely with your doctor to weigh the benefits and risks of potential treatments and how you can limit or prevent joint damage and disability.

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2021 Dec 12
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