[Left]: X-ray shows a mass arising from the left proximal humerus and extending into the adjacent shoulder soft tissues with really aggressive periosteal reaction ("hair on end"). The proximal humerus itself is also heterogeneous with lucent areas. The lateral surface of the upper humerus shows "saucerization," where the cortex is thinned out and looks like a saucer seen on edge.
[Middle]: MRI IR sequence shows a hyperintense bony mass with large soft tissue component.
[Right]: MRI postcontrast T1 IDEAL shows that the mass is enhancing.
This turned out to be high-grade surface osteosarcoma.
It looks like white tendrils emanating from the bone, pushing into the cloudier area. Definitely looks off, as you should not have tendrils like that on an X-ray.
