Mono-ostotic disease with claviclular expansion and surroudning inflammatory change. The differential is between an agressive bone tumor (e.g. Ewing sarcoma), LCH, osteomyelitis and CRMO.

Biopsy returned inflammatory cell only.

Diagnosis of CRMO was made and there was symptomatic improvement on treatment. Follow up imaging demonstrates reduction in the inflammatory change around the clavicle.