[Villonodular synovitis of the knee: about 20 cases].

Pigmented villonodular synovitis (PVNS) is a rare benign proliferation of synovial joints, serous bursa, tendinous sheaths of unknown etiopathogeny. We here report 20 cases of PVNS of the knee recorded at the Avicenne Military Hospital, Marrakech over a period of 9 years, from January 2000 to December 2009. This study aimed to identify the specific features of this lesion and to examine its anatomoclinic and prognostic aspects.