Recurrent Parathyroid Carcinoma

The study will be an effectiveness study. The study will include enrollment of a total of 20 patients with at least one PC lesion for ultrasound guided RFA to PC recurrence in the neck to assess the effectiveness in reducing patient's hypercalcemia. Patients will have surgically proven PC from prior parathyroidectomy and suspicious PC visible on ultrasound and request for treatment for uncontrolled hypercalcemia (Figure 1).