FDG-anorectic parathyroid carcinoma with FDG-avid bone metastasis on PET/CT images.

A 53-year-old man complained of aggravated left hip pain of more than 2 months. Whole-body (18)F-FDG PET/CT revealed only 1 hypermetabolic lesion in the left ilium. Histopathologic examination of the lesion suggested metastatic disease. Blood tests documented mildly elevated blood calcium and parathyroid hormone. Subsequent neck ultrasonography, contrast-enhanced CT, and dual-phase scintigraphy with (99m)Tc-MIBI showed a right parathyroid tumor, which was confirmed to be a parathyroid carcinoma postoperatively. We report a case of parathyroid carcinoma rarely encountered with a FDG-negative primary but a FDG-positive metastasis on PET/CT images.