What is tenosynovial
giant cell tumor (TGCT)?

TGCT is not cancer, but it can be life-altering

TGCT is a type of chronic, rare disease that can lead to ongoing pain and long-term joint damage.

An overview of TGCT

Watch to learn more about TGCT and how it grows.

TGCT is known by other names

TGCT can be called by different terms, depending on various medical resources, areas of the world, and some doctors. PVNS, GCT-TS, and TGCT are terms that refer to the same disease.

While typically noncancerous (nonmalignant), TGCT is a chronic and debilitating tumor occurring in or around a joint. It can cause pain, swelling, stiffness in the affected joint, and other symptoms. TGCT can reduce the function of small and large joints. In some cases, it can damage them. Surgery may be a cure for many people with TGCT. For some, however, tumors may grow back after surgery.

GCT-TS, giant cell tumor of the tendon sheath; PVNS, pigmented villonodular synovitis; TGCT, tenosynovial giant cell tumor.

PVNS, GCT-TS, and TGCT are terms that refer to the same disease
A TGCT tumor forming

What causes TGCT?

Scientists believe that TGCT tumors start in cells that line the joints. A small number of these cells can have a defect that causes them to make too much of a protein called colony-stimulating factor 1 (CSF-1). These defective cells merge and form the tumor.

Extra CSF-1 is thought to work in 2 different ways. It acts like a magnet to attract inflammatory cells to the joint lining, which causes swelling, and it causes tumor cells to multiply.

A TGCT tumor forming

TGCT may return after surgery

Depending on severity, TGCT may return after surgery in 4 years or sooner. The estimated recurrence rates are up to 15% for localized TGCT and up to 55% for diffuse TGCT. In addition to being painful, multiple surgeries limit range of motion and come with risk of infection.

For patients with TGCT not likely to improve with surgery, talk to a doctor about Turalio® (pexidartinib) as a treatment option.

4 years icon
Siobhan, Turalio patient and brand ambassador since 2021
TGCT has a different feel. When the disease came back after the knee replacement, I knew it.

–Siobhan

Siobhan, Turalio patient and brand ambassador since 2021
Share your TGCT story Hear more of Siobhan’s story

There are 2 types of TGCT

TGCT is classified into 2 types: diffuse and localized. If you have TGCT, it’s important to understand the differences between the 2 types and how each can affect your life.

Symptoms and disease features

Diffuse TGCT: 10% to 20% of all TGCT cases

Image representing common locations of diffuse TGCT in the body Image representing common locations of diffuse TGCT in the body

The circles represent common locations of diffuse TGCT. The large circle indicates the joint most commonly affected. Typically, only one joint is affected at a time.

Tumor locations

  • Tumors are most commonly seen in large joints
  • Tumors most often occur in the knee
  • Tumors can also occur in the hip, ankle, elbow, and shoulder joints

Common symptoms

  • Pain and tenderness
  • Locking of joint
  • Swelling (can be due to excess blood and fluid in the joint)
  • Limited movement in joint (range of motion)

Features and recurrence (growing back after treatment)

  • Tumors are usually larger than 5 centimeters (2 inches)
  • The borders of the tumors are not easy to see in surgery
  • Tumors typically grow in the spaces between joints and in tissues that line and surround joints
  • In some people, the disease may be linked to joint problems that get worse over time
  • Tumors mostly affect one joint and grow slowly over time
  • Tumors can recur after surgery in up to 55% of patients

Age and gender

  • Diffuse TGCT tends to affect younger people, but it can occur in people of any age
  • Diffuse TGCT is usually first diagnosed in adults under 50 years of age
  • Reported to be more common in women than in men

Symptoms and disease features

Localized TGCT: 80% to 90% of all TGCT cases

Image representing common locations of localized TGCT in the body Image representing common locations of localized TGCT in the body

The circles represent common locations of localized TGCT. The large circle indicates the joint most commonly affected. Typically, only one joint is affected at a time.

Tumor locations

  • Tumors are commonly seen in small joints
  • Tumors most often occur in the fingers and toes
  • Tumors can also occur in other joints, such as the wrist, ankle, foot, knee, elbow, or hip

Common symptoms

  • Swelling without pain (most common)
  • Pain that develops as the tumors grow (in some patients)
  • Limited movement in joint (in some patients), also called limited range of motion

Features and recurrence (growing back after treatment)

  • Tumors have a somewhat rounded, small shape; the borders of the tumors are easy to see in surgery
  • Larger tumors can appear in larger joints
  • Tumors mostly affect one joint and grow slowly over time
  • In rare cases, tumors may lead to damage of nearby joint or bone, or they can affect the skin
  • Tumors can recur after removal by surgery in up to 15% of patients

Age and gender

  • Localized TGCT is typically seen in people 30 to 50 years of age, but it can occur in people of any age
  • Reported to be more common in women than in men
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Treating TGCT

Learn how TGCT is managed.

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TGCT treatment centers

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