What causes Pigmented villonodular synovitis ?
What causes pigmented villonodular synovitis? The exact cause of pigmented villonodular synovitis (PVNS) is unknown.  Some doctors believe that it is similar to arthritis, arising from swelling (inflammation) of the joint tissue. Others believe it develops like a tumor, caused by cells growing and multiplying more quickly than usual. The association between a history of trauma and the development of  PVNS is unclear. One study found that 56% of individuals with PVNS had a history of previous trauma, while other studies have found a much lower incidence.  There have been studies suggesting that PVNS could be caused by specific genetic changes in the cells lining the joint. More studies are needed to research this association.