18F-FDG-Detected Brown Tumor Confined to the Maxillary Bone With Parathyroid Adenoma

Brown tumor is a reactive osteolytic lesion associated with hyperparathyroidism and an extremely rare form of a single lesion in the maxilla. We report the case of a 57-year-old woman with renal dysfunction, nasal obstruction, and hypercalcemia. MRI and CT revealed a huge osteolytic lesion in the maxilla. 18F-FDG PET/CT demonstrated marked FDG uptake within the mass and the lower-left lobe of the thyroid gland. 99mTc-methoxy-isobutyl-isonitrile scintigraphy suggested that this accumulation was a parathyroid adenoma. Parathyroid adenoma resection was performed, and the maxillary tumor was diagnosed as brown tumor. FDG PET/CT was helpful in evaluating brown tumor and detecting parathyroid adenoma.