The differential in this case is between a primary agressive bone tumor (e.g. Ewing sarcoma) or a process such as LCH or an inflammatory osteitis (e.g. CRMO).

A whole body MRI is useful to determine whether there are other lesions that might narrow the differential or offer another site for biopsy.

In this case, there were no other abnormalities.

A biopsy was performed that excluded an underlying neoplastic process and the diagnosis of CRMO was made. Treatment resulted in a reduction of the periostotic inflammation and improved pain control.