Scintigraphic demonstration of an ectopic parathyroid adenoma

Dual isotope subtraction imaging is a well-accepted technique valuable in localizing not only cervical adenomas but also the relatively rare ectopic parathyroid adenomas. In this patient with hyperparathyroidism, the parathyroid scan demonstrated abnormal focal thallium uptake in an unusual mediastinal location, which correlated with a para-aortic mass seen on a CT scan. At surgery, ectopic parathyroid adenoma was proven.