Tenosynovial giant cell tumor

A tenosynovial giant cell tumor (TGCT) is a soft tissue tumor. A TGCT starts as a growth of synovial cells in the synovium. The synovium is tissue that lines the joints and the structures around them. Those structures include bursae and tendon sheaths. Bursae are tiny fluid-filled cushions that protect joints. A joint is where two or more bones meet. A tendon connects bone to muscle. Tendon sheaths cover tendons and help them move smoothly.

There are two main types of TGCT.

Localized TGCT used to be called giant cell tumor of the tendon sheath (GCTTS). Localized TGCT is sometimes called nodular TGCT. It typically appears as a lump. It often affects the fingers and hand near tendon sheaths or finger joints.

Diffuse TGCT used to be called pigmented villonodular synovitis (PVNS). Diffuse TGCT can grow through several parts of a joint and into nearby tissues. It typically affects large joints in the knees, hips and ankles. It can grow into nearby tissue and damage a joint.

Both types are now grouped under the name tenosynovial giant cell tumor (TGCT). But you still may see GCTTS and PVNS in medical reports.

The two types look very similar under a microscope. But they typically grow and act differently. TGCTs are often benign, which means they are not cancer.

TGCTs most often affect adults in their 30s to 50s. These tumors are very rare in children, but they can happen at any age.

Types

The main types of TGCT are localized TGCT and diffuse TGCT. Localized TGCT also may be called nodular TGCT. Both types often are benign. The cells of these types look alike under a microscope. The types are often diagnosed by how the tumor grows and looks on imaging.

Localized TGCT. This type usually appears as one or more well-defined lumps in one area. This means it is less likely to spread through the joint lining. It often affects the fingers and hand near tendon sheaths or finger joints. It less commonly affects the foot, ankle or knee.

Diffuse TGCT. This type usually grows through many parts of a joint and into nearby tissue. It typically affects large joints in the knees, hips and ankles. It can involve several parts of a joint and extend into nearby soft tissues, tendons and muscles.

Malignant TGCT is a separate, extremely rare cancer that is different from localized and diffuse TGCTs.

Symptoms can vary by TGCT type and where the tumor is located.

Localized TGCT. This type, also called nodular TGCT, most often causes a firm lump that grows slowly. The lump often does not hurt. However, some people with localized TGCT may feel some pain and tenderness. If the lump or tumor is near a finger joint, it may be hard to bend and straighten the finger. If it presses on a nearby nerve, it may cause a tingling feeling.

Diffuse TGCT. The symptoms of diffuse TGCT may include:

• Swelling.
• Stiffness.
• Pain or tenderness.
• Reduced joint movement.

Diffuse TGCT can cause bleeding inside the joint. The bleeding may happen more than once.

Over time, diffuse TGCT can damage the joint's cartilage and nearby structures, including bones and tendons.

When to seek care

Make an appointment with a healthcare professional if you have symptoms that worry you or are not going away. These symptoms may include:

• A new, growing lump or tumor under the skin near a finger, wrist or ankle or around a joint.
• Joint pain, stiffness or swelling where the lump is growing.
• Trouble bending or straightening a finger.

If you have already been diagnosed with TGCT, call your healthcare team if your symptoms get worse or new symptoms develop.

The exact cause of localized and diffuse TGCTs is not known. Researchers have found gene changes in some TGCT tumors.

The exact risk factors for TGCT are not known. A TGCT can occur at any age. Risk may vary by age and sex at birth.

Age. TGCT can happen at any age. Localized TGCT is often more common in adults in their 30s to 50s. Diffuse TGCT usually affects younger people but can happen at any age. TGCT in children is extremely rare.

Sex at birth. Localized TGCT and diffuse TGCT are more common in women.

Healthcare professionals use physical exams and imaging tests to look for TGCTs. In most cases, magnetic resonance imaging (MRI) can diagnose a suspected TGCT. A biopsy may be needed to confirm the diagnosis. A biopsy is a procedure to remove a tissue sample for testing in a lab.

Several other conditions can look like TGCT. The healthcare team may need to make sure the tumor is not:

• Rheumatoid arthritis.
• Fibroma of the tendon sheath.
• Foreign-body or inflammatory granuloma.
• Ganglion cyst.
• Hemosiderotic synovitis.
• Synovial chondromatosis.
• Tendon xanthoma.

Physical exam

A member of your care team may ask about your symptoms and health history. A physical exam may help the care team learn more about your symptoms and look for other clues that help with your diagnosis.

Imaging tests

Images help the care team see where the tumor is and the tissues around it.

MRI and X-ray are the main imaging tests for TGCT. Computerized tomography (CT) scan or ultrasound also may be used, depending on the tumor. Talk with your healthcare team about which imaging tests you may need.

• MRI. This type of imaging uses a magnetic field and radio waves to create pictures of the inside of the body.
• X-ray. This type of imaging takes pictures of the structures inside the body.
• (CT) scan. This type of imaging uses X-ray techniques to create detailed images of the body.
• Ultrasound. This type of imaging uses sound waves to make pictures of structures inside the body.

Biopsy

A biopsy is a procedure to remove a sample of tissue for testing in a lab. How a member of the care team collects the sample depends on the tumor's size and location.

Types of biopsy procedures for TGCT may include:

• Image-guided core needle biopsy. This method uses imaging, such as ultrasound or CT, to help a member of your care team guide a needle through the skin and into a tumor to collect tissue samples.
• Excisional biopsy. This method involves removing an entire lump or tumor from your body to test it in a laboratory. A decision to use this method depends on the tumor's size, location, imaging features and the treatment being considered.

Your tissue then goes to a lab, where a pathologist studies it to help confirm the diagnosis.

The treatment plan for a tenosynovial giant cell tumor (TGCT) depends on the type of TGCT you have, the symptoms the tumor is causing and the location of the tumor.

People who don't have any symptoms might be monitored by their care team. Treatment often is needed if symptoms worsen and affect function, such as when a TGCT affects your finger joint and you cannot bend or straighten your finger.

Localized TGCT

Surgery

Treatment for localized TGCT often involves removing the tumor. This is called an excision. The goal is to remove the entire tumor and protect nearby nerves, joints, tendons and blood vessels.

In some cases, a camera-guided procedure called arthroscopy may be used.

Diffuse TGCT

Surgery

Diffuse TGCT is typically harder to remove than localized TGCT. The treatment often is surgery if the care team believes the tumor can be fully removed without affecting how the joint works. The surgeon typically removes the tumor and affected joint lining. Removal of the joint lining is called a synovectomy. If full removal is not safe, removing part of the tumor may be an option. Discuss the expected benefits and other treatment options with your care team.

Targeted therapy

Targeted medicines block certain signals that help TGCT cells grow. These medicines may be considered when surgery cannot remove the tumor or if a tumor comes back after surgery. If medicine is an option for you, your care team explains what treatment may be given.

Radiation therapy

Radiation therapy may be an option for some people with diffuse TGCT. It usually is considered only when the tumor has come back or if other treatments did not work.

Radiation can cause long-term issues. It may damage the joint and lead to arthritis or stiffness. It also can cause scarring in nearby tissues and may increase the risk of a new cancer in the future.

Follow-up after treatment

It is important to follow up with your healthcare team after treatment. TGCT can return after surgery. This is called a recurrence. Talk to your healthcare team about how often you should schedule medical appointments and what tests you might need in the future.

A tenosynovial giant cell tumor (TGCT) diagnosis can bring many feelings and questions. The following ideas may help.

• Learn about TGCT to make decisions about your care. If you'd like to know more about your condition, ask your healthcare team for the details. Ask for trusted sources where you can learn more about your treatment options. Knowing more about your TGCT and your options may help you feel more confident when making treatment decisions.
• Talk with someone you trust. Talking with someone you trust may help as you manage a TGCT diagnosis. This could be a friend, family member, counselor, medical social worker or faith leader.
• Talk with other people who have TGCTs. You may find it helpful and encouraging to talk to others who have been diagnosed with TGCT. Ask your healthcare team about support groups in your area. Find support through Mayo Clinic Connect, an online community where you can find support, practical information and answers to everyday questions.

Make an appointment with a doctor or other healthcare professional if you have any symptoms that worry you or are not going away. If tests show you might have a tenosynovial giant cell tumor (TGCT), your healthcare team will likely refer you to a specialist.

Here's some information to help you get ready for your appointment.

What you can do to prepare

• Write down your symptoms, including any that may seem unrelated to why you made the appointment.
• Make a list of all medicines, vitamins or supplements that you're taking and the doses.
• Keep all records related to your diagnosis and treatment. Organize them in a binder or folder that you can take to appointments.
• Consider bringing someone you trust. This person may help you remember what you discuss during the appointment.
• Write down questions to ask your healthcare professional.

Questions to ask your doctor

Your time with your healthcare professional may be limited. Prepare a list of questions so that you can make the most of your time together. List your questions from most important to least important in case time runs out. Some basic questions to ask about tenosynovial giant cell tumor (TGCT) include:

• What should I know about TGCT?
• Do I need more tests?
• What treatment options do I have?
• What are the benefits and risks of each treatment you recommend?
• Could the tumor return after treatment?
• Are there any clinical trials or newer treatments that I should consider?

You also can ask other questions during your appointment.

What to expect from your doctor

Be prepared to answer some questions about your symptoms and your health, such as:

• When did you first notice symptoms?
• Are your symptoms always present, or do they come and go?
• How bad are your symptoms?
• What seems to make your symptoms better?
• What seems to make your symptoms worse?