Tenosynovial giant cell tumor (TGCT)
Includes giant cell tumor of the tendon sheath (GCT-TS) and pigmented villonodular synovitis (PVNS)
TGCT is a type of non-malignant tumor occurring in or around a joint that can reduce function and cause damage to neighboring tissues. One type of TGCT is called localized; this type is often cured with one surgery. After it is removed, localized TGCT may come back, or recur, up to 15% of the time. The more challenging—and less common—type of TGCT is called diffuse; this type can be harder to treat and is more likely to recur. After it is removed, diffuse TGCT may grow back in 20% to 50% of people. If TGCT recurs, it can result in multiple surgeries and damage to the affected joints over time.
Talk with your doctor to learn more about TGCT.
What makes TGCT grow?
With TGCT, a small number of cells in the lining of the joint have a defect. The defect makes them produce too much of a protein called colony-stimulating factor 1 (CSF-1). Researchers believe the protein acts like a magnet: it attracts other cells (that don’t belong there) to merge and form the tumor, which can cause pain and swelling.
Frequently asked questions
Common questions about TGCT
You may have a lot of questions about TGCT. We've included a few key questions and answers below to get you started. You’ll find many more in the Resources section of this site. You can share the questions below with friends and family with just one click. You can also let us know whether each question is helpful by clicking the thumbs-up or thumbs-down icon.
While TGCT is a tumor, it is not cancer. TGCT is a type of non-malignant tumor occurring in or around a joint that can reduce function and cause damage to neighboring tissues.
While every person’s experience with TGCT is different, a tumor regrowth may be marked by the return of symptoms, increased pain, decreased range of motion without explanation, and/or a new mass.
Talk to your doctor about scheduling follow-up appointments to monitor your condition. If you have been treated for TGCT and your symptoms have returned or you are concerned that that your tumor may come back, talk to your doctor.
Some experts believe that healthcare providers from different specialties working together helps to improve the outcomes of people with TGCT.
The National Comprehensive Cancer Network® (NCCN) recommends that people with TGCT/PVNS be evaluated and managed by a multidisciplinary team. The team should have experience and expertise in sarcoma (a group of tumors that grow in bones or connective tissues like muscle and fat). For a list of doctors and specialists who may be involved in managing TGCT, visit our TGCT treatment section.
We’ve created a simple guide that you can print and take to your next doctor appointment. It includes a list of common topics and questions about TGCT, as well as space to add your own questions.
We have created a set of fact sheets that cover basic information about localized and diffuse TGCT. Please download them to help you, friends, family—anyone in your life—learn more about these rare tumors and how they may affect you.