Radiology Cases Fibrosarcoma

Description: Fibrosarcoma is fairly rare. It has a peak incidence of 35 yrs. It usually starts in the bone and 80% of cases occur around the knee. Some of these cases will be in the soft tissue. Flat bone involvement is unusual. The tumour is usually a medullary lesion, although it can rarely be periosteal. With large tumours, the site of origin is inferred from the centre of radius of the mass. The tumour is primary lytic with no visible sclerosis. There is a wide endosteal margin between normal and abnormal bone. The tumour may contain spotty densities of contained residual dead bone which may confuse its appearance with metaplasia in other tumours.