Abnormal FDG Uptake on PET/CT Due to Periosteal Reaction Caused by Hypervitaminosis D in a Pediatric Patient.

A 7-year-old boy presented with diffuse bone pain. FDG PET/CT was performed to find the possible underlying malignant cause of hypercalcemia. The images demonstrated multiple foci of abnormal FDG activity at the sites of periosteal reaction. In addition, calcium deposit was noted in the basal ganglia, stomach, and the colon. History taking revealed that the patient had routinely taken an over-the-counter "supplement" that contains a high dose of vitamin D. One week after calcitonin therapy and stopping the supplement, the patient became symptom free. This case suggests that hypervitaminosis D might cause hypermetabolic periosteal reaction on FDG PET/CT imaging.