During the last decade the therapeutic approach to musculoskeletal tumors has changed dramatically, from ablative surgery with ampu- tation ofthe limb to reconstructive surgery with transplantation of bone and vessels combined with radio-and chemotherapy. This has changed the demands on radiologists and pathologists to a considerable degree. At the same time there has been a manifold increase in the diagnostic possibilities offered by modern radiology, with several new modalities affording a potential for morphologic depiction and tissue character- ization that was unattainable a decade ago....