We often find repeated joint pain and swelling in common conditions such as osteoarthritis or inflammatory arthritis, such as gout. One rare cause of recurrent joint swelling is pigmented villonodular synovitis or PVNS. What is PVNS, and how do we diagnose and treat it?
What is PVNS?
PVNS occurs when the tissue lining the joint, also known as the synovial lining, overgrows and thickens, forming villous projections. These abnormal tissues often contain hemosiderin, a blood byproduct that causes joint swelling like blood. The condition can damage surrounding cartilage and bone, causing joint degeneration over time. While we often describe PVNS as a tumour, it is not usually cancerous.
PVNS is rare, affecting about two people in every million. It commonly affects the knee joint but can also affect the hip, shoulder, elbow, and ankle joints. In one study of 90 patients with pigmented villonodular synovitis, over 90% of cases were found in these joints. The growth can be localised to one area or diffuse, involving the entire synovial lining.
Symptoms and signs
PVNS typically affects one joint, but in some cases, it can affect more than one joint. Common symptoms include the following:
- Joint Swelling: Persistent and often painless in early stages, but worsening over time. Sometimes, PVNS can present as a painless lump on the wrist or lower leg.
- Pain: Aching or throbbing joint pain that worsens with activity.
- Stiffness: Limited range of motion in the affected joint.
- Locking or Clicking: Mechanical symptoms due to joint effusion or tissue overgrowth.
- Warmth and Tenderness: The joint may feel warm and tender to the touch.
- Recurrent Hemarthrosis: Blood within the joint due to minor trauma.
Diagnose PVNS
Your doctor will examine your affected joint to look for swelling, tenderness and restriction in movement.
Generally, we use imaging to confirm a diagnosis. MRI is the gold standard for PVNS diagnosis, revealing characteristic features like synovial thickening, hemosiderin deposition, and joint effusion. Specific MRI images called gradient echo sequences produces a ‘blooming effect’, which is highly characteristic of PVNS. These specific sequences are not routinely performed for a standard joint scan. So, if your doctor suspects PVNS, you may need further sequences to confirm the diagnosis.
A biopsy, which samples synovial tissue, may provide more information in identifying the features of PVNS. The biopsy sample can be examined under a microscope to assess for the presence of particular types of cells or other changes consistent with PVNS.
Treatment Options for PVNS
Once we make the diagnosis, NSAIDs may reduce pain and swelling in the short term.
As PVNS can cause progressive joint damage, your doctor will offer you interventions such as surgery or radiation.
Surgical excision is the most definitive treatment. If the tumour is localised, doctors can surgically excise it. If it is diffuse, doctors may offer arthroscopic or open synovectomy. In some cases, the tumour may return after surgery.
Sometimes, when the tumour has recurred or cannot be excised, radiation therapy is used to shrink it. Radiation therapy can effectively reduce the risk of recurrence.
Other Commonly Asked Questions about Pigmented Villonodular Synovitis:
How rare is PVNS?
It is infrequent. About 2 in 100000 people will develop pigmented villonodular synovitis.
What are the causes of PVNS?
We don’t know. However, about 50% of cases were precipitated by trauma, suggesting bleeding into the joint may precipitate growth of the synovium.
Can PVNS occur outside joints?
Yes, we often call this condition GCTTS also known as giant cell tumour of the tendon sheath. Generally, this condition occurs more frequently in women between 30-50. Most cases occur in the wrist and hand.
Just like PVNS, MRI with special echo gradient sequences is the gold standard in diagnosing GCTTS, although ultrasound can help as well.
Final word from Sportdoctorlondon about Pigmented Villonodular Synovitis
Pigmented villonodular synovitis is challenging due to its rarity, variable presentation, and potential for joint destruction. If you experience persistent joint swelling, pain, or dysfunction, consult a sports medicine doctor for evaluation. Advances in imaging, surgical techniques, and targeted therapies offer hope for improved outcomes in PVNS management.
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