What is pigmented villonodular synovitis?

Pigmented villonodular synovitis (PNSV) is a joint disease characterized by inflammation of the synovial membrane, which is the lining of the joints. This inflammation can lead to the formation of synovial nodules or masses, which contain inflamed synovial tissue and the pigment hemosiderin, a breakdown product of hemoglobin.

The synovial membrane becomes inflamed and forms nodules or masses inside the joint. These nodules can vary in size and number.

Pigmented villonodular synovitis usually affects large joints, such as the knee, although it can also occur in other joints.

Patients with pigmented villonodular synovitis may experience joint pain, swelling, and limitation in the range of motion of the affected joint. The presence of synovial nodules may be palpable.

Diagnosis is based on clinical evaluation, medical history, and imaging. Imaging tests such as magnetic resonance imaging (MRI) or ultrasound may be helpful in visualizing synovial inflammation and nodules.

Treatment for pigmented villonodular synovitis may vary and will depend on the severity of the symptoms and the involvement of the joint. Options may include:

  • Nonsteroidal anti-inflammatory drugs (NSAIDs) to relieve pain and reduce inflammation.
  • Aspiration or surgical removal of synovial nodules.
  • In some cases, surgery may be necessary to address more extensive or recurring problems.

Pigmented villonodular synovitis is a rare disease, and its clinical course can be variable. Although not usually malignant, the presence of synovial nodules can affect joint function and cause painful and restrictive symptoms.