Fact-sheet: Osteosarcoma
Updated on 09/01/2021 at 11:42 AM
View all RADEOS cases associated with this fact-sheet
Definition
Rare form: Juxtacortical osteosarcoma (4% of bone sarcomas), distinguished by its predominance in women between 40 and 50 years of age, and a better prognosis related to slow growth
Clinical features
After several local recurrences, juxtacortical sarcoma can dedifferentiate into a high-grade sarcoma and be complicated by pulmonary metastases.
Radiography
Distinctive imaging appearance of juxtacortical osteosarcoma: arises from the outer surface of the bone (usually the diaphyseal-metaphyseal junction of the posterior femur), which it tends to encircle; it adheres firmly to the cortex over a very limited area and has a sharply defined, lobulated outer contour; the tumor matrix is almost completely calcified, but contains areas of osteolysis, well seen on CT, which may correspond either to foci of high-grade sarcoma or to benign fibrous or cartilaginous tissue. There is no periosteal reaction.
The prognostic significance of medullary invasion is controversial.
Differential diagnosis
Degenerated exostosis
Myositis ossificans