[Reticulum cell sarcoma of the pelvis. Diagnostic and therapeutic problems].

Diagnostic and operative problems of malignant bone tumors of the pelvis are discussed. Especially mentioned is resection therapy of pelvis tumor including large parts of the pelvis and the hip joint. A case-report is given. In this case replacement of the entire hip joint was successfully performed with a special prosthesis. Stabile fixation of the prosthesis is one of the major problems to be dealth with. Follow-up examination of our patient one year after the operation showed no loosening of the prosthesis and free movement of the hip joint iwth partial loack capacity of the leg.