Serendipitous Diagnosis of Tertiary Hyperparathyroidism in a Case Purportedly thought to have Skeletal Metastases.

Tertiary hyperparathyroidism (THPT) is characterized by over secretion of parathyroid hormone caused by long-standing secondary hyperparathyroidism. THPT can affect the bones as well as cause extraskeletal calcifications. The bony lesions often mimic multiple skeletal metastases or multiple myeloma. We report a case of a 48-year-old man with chronic kidney disease on dialysis, who presented with chief complaints of low back ache and swelling over the left clavicle. In view of clinical suspicion of malignancy with bony metastases, he underwent 18 F-fluorodeoxyglucose positron emission tomography/computed tomography and was subsequently found to have parathyroid adenomas, which were confirmed on 99m Tc-methoxy-isobutyl-isonitrile scintigraphy.