Delayed massive soft tissue uptake of Tc-99m MDP after radiation therapy for cancer of the breast.

A patient with a history of breast cancer and known lung metastases was referred for a bone scan to investigate the cause of severe neck and right shoulder pain. The bone scan showed massive uptake of the radiopharmaceutical in the soft tissue surrounding the right shoulder. A review of the patient's history indicated that the patient had undergone radiation therapy to the right upper thorax and breast area 14 months previously and an acute radiation dermatitis of the proximal right arm and should had developed. This had long since resolved. Physical examination and plain radiographs of the right shoulder and humerus failed to demonstrate any abnormality.