X-ray
Frontal
Lateral
Does this appearance change your thoughts on the what differential is more likely?
Now FD and SBC are equally likely, as this appearance would be atypical for FD, and the age would be atypical for SBC.
The lesion extends from the proximal humeral physis into the distal third of the humerus. There is moderate medial angulation and lateral offset of the primary oblique fracture, with multiple smaller comminuted fragments of thin cortical bone, making the lesion appear more cystic in nature.