Tenosynovial Giant Cell Tumors

Tenosynovial giant cell tumors (TGCTs), which was previously known as pigmented villonodular synovitis, are a group of rare, benign tumors that form in the synovium (tissue that lines the joints), the tendon sheath (tissue that covers the tendons) or the bursa (a fluid-filled sac between bones, tendons and muscles). They can grow and cause damage to the surrounding tissue and structures of your body. Tenosynovial giant cell tumors are very rare. Fewer than 50 in every one million people worldwide develop them each year.

Types & Stages 

There are two types of tenosynovial giant cell tumors. They are:

• Localized TGCT. Smaller joints tend to be affected, such as digits and parts of your foot.
   
• Diffuse TGCT. Large joints tend to be involved, commonly your knee.

Signs & Symptoms 

Common symptoms of a tenosynovial giant cell tumor include:

• A noticeable bump or lump
• Pain that gets worse when you move the affected part of your body
• Swelling
• A catching, locking or popping feeling when you move your joint
• Heat or warmth on the skin around your joint
• Stiffness
• Your joint feeling unstable or weak

Diagnosis 

Depending on where the tumor is, you might be able to feel and see it under your skin. Your provider will examine the lump and the area around it. They will also use:  

• Imaging tests.  These may include:
   
  • X-rays. A diagnostic test that uses invisible electromagnetic energy beams to produce images of internal tissues, bones and organs onto film.
     
  • Magnetic resonance imaging (MRI). A diagnostic procedure that uses a combination of large magnets, radiofrequencies and a computer to produce detailed images of organs and structures within the body.  
     
  • Ultrasound. A medical imaging technique that uses high-frequency sound waves to create real-time pictures of the body's internal organs, soft tissues and blood flow.
     
• Biopsy. A procedure to remove some cells for testing. The sample might be removed with a needle put through the skin. Or the sample might be taken during surgery to remove the cancer. The type of biopsy depends on the cancer's location.

Treatment

Tenosynovial giant cell tumors are usually removed with surgery including:  

• Arthroscopy. A minimally invasive surgery on a joint, like your knee, shoulder, ankle or elbow. Your surgeon will make a few tiny cuts on the outside of your body then insert an arthroscope (a long, thin tube with a video camera and light on the end) to see inside your joint. They’ll use small tools to excise (remove) the tumor and any other damaged tissues.
   
• Open surgery. Also known as traditional or conventional surgery, in which a single large incision is made to access the surgical site.  
   

Causes & Risk Factors 

Anyone can develop a tenosynovial giant cell tumor, but they’re more common in females and adults ages 30 to 50.

Screening 

There is no routine screening for tenosynovial giant cell tumor.