[Semi-malignant giant cell synovioma as an incidental finding in open dislocated fracture of the upper ankle joint].

A rare statement is demonstrated with reference to a case concerning a sixteen years old girl who caught an open luxation fracture of her upper ankle joint by a sudden fall from a horse on August 8, 1988. During the operative treatment a spontaneously loosing soft tissue tumor of plumlike size could be obtained. The histological analysis proved a semimalignant giant cell-synovialom.