[Ultrasound-guided anhydrous ethanol and microwave ablation for functional parathyroid cyst: a case report].

We report a case of functional parathyroid cyst treated by ultrasound-guided anhydrous ethanol sclerotherapy and microwave ablation. The 63-year-old female patient was diagnosed to have functional parathyroid cyst with hypercalcemia, high PTH and cystic space-occupying lesions in the neck by ultrasound, radionuclide scanning and PTH measurement of the cystic fluid. The patient refused to receive cyst resection, and anhydrous ethanol sclerotherapy with microwave ablation was performed under ultrasound guidance. The procedure was completed smoothly without any complications either during or after the operation. Follow-up examination of the patient at 18 months after the operation showed a significant reduction of the mass and normal blood calcium and iPTH levels, demonstrating a clinical cure of the patient. Ablative treatment of functional parathyroid cyst has not been documented so far. This approach provides a minimally invasive treatment modality for such cases where surgical resection is not an option, but its efficacy and safety need to be evaluated in more cases with longer follow-up time.