[Villonodular synovitis. An uncommon localization: the ankle. Apropos of a case]

The authors report an uncommon soft tissue tumor, a diffuse giant cell tumor of tendon sheath. The location is uncommon too, the ankle, behind tibial shaft and forward achilleus tendon. The primary diagnosis of ankle and leg lymphoedema, has been for a long time. But CT Scan and MRI allowing the discovery of a firm and multinodular mass, have permitted surgical excision and histological diagnosis. This case agrees with the literature review. The pigmented villonodular synovitis is rather uncommon in comparison to localized form. Young people and lower extremities are more affected; symptoms are of relatively long duration. Histological examination gives diagnosis but surgical excision has to remove the tumor completely as possible because of local recurrence rate of about 50%.