Primary Rosai-Dorfman disease of the bone in a patient with history of breast cancer: appearance on 99mTc-MDP scintigraphy, CT, and X-ray.

A 49-year-old woman with history of breast cancer presented with pain at the level of the left anterior proximal tibia. An x-ray of the tibia demonstrated a lytic cortical lesion that prompted a whole-body 99mTc-MDP bone scan. The bone scan revealed intense bone remodeling at the level of the tibial lytic lesion and in the cervical spine.