Fibrous Dysplasia of Frontal Process of Maxilla: False-Positive Finding on 18F-FDG PET in Multiple Myeloma.

18F-FDG focal uptake in bone is always concerning, especially in patients with a history of cancer. We report a case of increasing hypermetabolic activity of a maxillary bone lesion in a patient with a history of multiple myeloma that was managed with definitive treatment. A targeted CT scan revealed that the abnormal 18F-FDG uptake was fibrous dysplasia. Vigilant interpretation is required for focal osseous activity on PET/CT in patients with a history of cancer to avoid false-positive readings.