Medical Malpractice Insurance for orthopaedic surgeons
Home » Arthroscopy » Pigmented Villonodular synovitis

Pigmented Villonodular synovitis


  • pigmented villonodular synovitis is a slow growing, benign, and locally invasive tumor of the synovium;
  • location: most often involves the knee (also in hip, ankle, elbow, etc.);
    • always consider PVNS in a younger patient with unexplained hip pain;
  • acute episodic attacks of pain and swelling may occur;
  • patients may have mechanical symptoms (locking and catching);
  • most have hemorrhagic, dark brown synovial fluid;
  • biopsy is diagnostic;
  • diff dx: rheumatoid arthritis: unlike PVNS, RA tends to affect multiple joints;
  • sub-types:
    • it usually presents as a monoarticular hemarthrosis, and may exist in a nodular or a diffuse form;
    • diffuse form:
      • disease may be active or inactive;
      • look for peri-articular erosions on radiographs;
      • diffuse mass may be present on exam;
    • nodular form:
      • less common than the diffuse form of the disease;
      • does not show the same destructive changes as the diffuse form of PVNS;
      • may cause recurrent hemarthrosis and aspirate may be of normal color (may not show classic brown color);


reference: Roentgenographic findings in pigmented villonodular synovitis of the knee.

MRI Findings


  • histologic characteristics are similar to GCT of tendon sheath;
  • classic cytoarchitecture consists of subsynovial nodular proliferation of large round, polyhedral, or spindle cells with prominent cytoplasm and pale nuclei;
  • phagocytic histiocyte-like cells are also present;
  • lipid-laden foam cells and multinucleated giant cells are interspersed with hemosiderin-laden cells that resemble lining cells;
  • giant cells appear to have phagocytic role;
  • findings include deposition of iron, foam cells, or giant cells;