[Localized pigmented vellonodular sunovitis, cause of knee hemarthrosis].

The pigmented vellonodular sinovitis (PVNS) is benign neoplasm with synovial proliferation and hemosiderin deposit, characterized by large compromising joints, especially the knee. At present, two variants of clinics, the diffuse form (PVNSD) and the localized (PVNSL) are described. Arthroscopic synovectomy and radiosynoviorthesis (RSO) is the treatment that has shown the best functional results. Nuclear magnetic resonance is an appropriate method for conducting the diagnosis of PVNSL.