Case I: A woman of 37 years old, complained pain and swelling in the lesion of the left hip during five months. Roentgenogram revealed diffuse osteolytic lesion with pathological fracture in the upper end of the left femur. En bloc total excision of the tumor was performed and a specially designed prosthesis was inserted. Microscopic diagnosis was giant cell tumor. Range of movement of the left hip joint was almost normal 3 years later.
Case II: A girl of 17 years old, was diagnosed as the diffuse giant cell tumor of the right femur. Two years after curettage and bonegrafting, the tumor recurred, and the same prosthesis as in Case I was inserted.
