What is Pigmented Villonodular Synovitis (PVNS)?

Pigmented villonodular synovitis or PVNS is a painful condition that causes the synovium within the joint to overgrow or thicken. The synovium is a thin, connective tissue that lines the inside of the joint capsule. The job of the synovium is to produce fluid which lubricates the joints. When this tissue thickens, it causes a growth of a tumor called pigmented villonodular synovitis (PVNS). The tumor, or PVNS is not cancer and does not metastasize (spread). PVNS is however, a progressive joint disease that continues to worsen and will eventually lead to bone damage and osteoarthritis. Pigmented villonodular synovitis can affect people of all ages, but it occurs most often in young adults from 20 to 50 years of age and most commonly occurs in the knee. PVNS is rare, only 2 out of every 1 million people will be affected. Due to the complexity of PVNS, it is important to find an orthopedic expert who has experience in identifying and treating PVNS. Our “best-in-class” orthopedic doctors are well versed in PVNS and can offer the best treatment advice during a telemedicine visit on our state-of-the-art virtual care platform.

What are the types of pigmented villonodular synovitis, or PVNS?

Orthopedic experts classify PVNS in two categories:

  • Non-localized PVNS – Also known as “Diffuse” PVNS and involves the entire joint lining. Diffuse PVNS is more common and can be more difficult to treat than local PVNS.
  • Local PVNS – Affects one area of the joint or only the tendons supporting the joint. Local PVNS usually responds well to treatment.

Who is susceptible to PVNS?

PVNS is rare in children and usually affects adults 20 to 50 years old. Women are at a slightly higher risk for PVNS than men. The condition is rare, just 2 in every 1 million individuals will have PVNS.

What causes pigmented villonodular synovitis?

The cause of this rare condition is unknown but some doctors suspect a link between PVNS and a recent injury. Heredity may also play a role for individuals more prone to inflammatory diseases or unchecked cell growth (growing benign tumors).

What are the symptoms of PVNS?

As the synovium in the joint thickens and enlarges it can cause the following symptoms:

  • Stiffness in the joint
  • Decreased range of motion
  • Rapid swelling of the joint
  • Mild to moderate pain the joint
    • PVNS is most commonly found in the knee, with the second most common area being the hip.
  • Pain that worsens with use or movement
  • Locking or catching sensation in the joint
  • Feeling of instability, like the knee or hip will not hold your weight
  • Hemarthrosis – when blood collects in the joint space, often with no associated trauma

How is PVNS – pigmented villonodular synovitis diagnosed?

PVNS may require several different diagnostic tests including:

  • X-ray – PVNS may not be detected initially by an x-ray, however PVNS can affect the bones by creating holes in the bone, caused by tumors. If not visible, an x-ray can help rule out other causes of pain.
  • MRI – Helpful in showing the soft tissues and the synovial lining. Synovial thickening and a tumor will show up on an MRI.
  • Joint aspiration – Fluid is removed from the joint and analyzed. PVNS will have a bloody joint fluid.
  • Biopsy – Often required in the presence of a tumor to determine if it is cancerous.

What is the treatment for pigmented villonodular synovitis?

PVNS does not “go away” and will not resolve on its own. Pigmented villonodular synovitis that goes untreated has the potential to destroy bone and cause long-term damage to the joint. Surgery to remove the tumor and painful synovial lining is called a synovectomy.

The experts at BICMD often prefer a minimally invasive procedure called arthroscopic surgery. This type of surgery involves smaller incisions than traditional “open” surgery and uses a small camera along with small, specialized instruments to complete the surgery within the joint capsule.

An open synovectomy may need to occur if the tumor is large and affects both sides of the joint (non-localized PVNS). If there is significant bone damage other treatments for PVNS may include:

  • Total joint replacement or an arthroplasty
  • Radiation – if the tumor cannot be removed completely through surgery
  • Drug therapy – Currently being studied for their ability to reduce cell growth within the joint.

Is there a cure for PVNS – pigmented villonodular synovitis?

Surgery is usually highly successful at treating PVNS, especially the local or non-diffused type of PVNS. Studies show between 10 percent and 30 percent of diffuse PVNS tumors grow back after surgery. It is important to see your doctor for several years after surgery to make sure the tumor has not returned.

For more information and resources on PVNS or pigmented villonodular synovitis in, or if you have been diagnosed with PVNS and would like to understand your treatment options, please contact our orthopedic specialists, by clicking on “Connect With a Doctor.” You will be connected to one of our orthopedic telemedicine experts through our state-of-the-art telemedicine platform.