Top left and right: X-rays showing a BIG right jaw mass. Whispy calcifications likely represent spiculated periosteal reaction, a very aggressive bony reaction.

Bottom left: CT in the bone/calcification window shows the periosteal reaction better.

Bottom right: MR in the T2 sequence shows the full extent of the jaw mass and how it extends far beyond the mandible’s margins, both outward and inward into the floor of mouth.

While this mass is very large, in general, jaw osteosarcoma has a better prognosis than conventional osteosarcomas.