Radiofrequency ablation of an intrathyroidal parathyroid adenoma with intraoperative parathyroid hormone monitoring: a case report of a novel technique.

Background: Primary hyperparathyroidism (PHPT) is classically treated by conventional parathyroidectomy, an open neck surgery. Radiofrequency ablation (RFA) has been shown as a safe minimally-invasive alternative to parathyroidectomy for the management of PHPT and has been shown to be effective in 60-90% of cases. Here, we present a patient successfully treated for persistent PHPT by RFA with simultaneous intraoperative parathyroid hormone (IOPTH) monitoring. Case Description: A 51-year-old female with a past medical history of resistant hypertension, hyperlipidemia, and vitamin D deficiency presented to our endocrine surgery clinic with PHPT. Neck ultrasound (US) localized a 0.79 cm lesion suggestive of a parathyroid adenoma. Parathyroid exploration resulted in the excision of two masses. IOPTH levels dropped from 259.9 to 204.7 pg/mL. No ectopic parathyroid tissue was found. Three-month follow-up demonstrated elevated calcium levels, suggesting persistent disease. A repeat neck US one-year post operation localized a suspicious hypoechoic sub-centimeter thyroid nodule, which was subsequently determined to be an intrathyroidal parathyroid adenoma. The patient elected to proceed with RFA with IOPTH monitoring, citing concern for increased risk of redo open neck surgery. Operation pursued without complication and IOPTH levels dropped from 270 to 39.1 pg/mL. The patient's only three-day post-operative complaints, occasional numbness and tingling, were completely resolved by her three-month follow up. The patient had normal PTH and calcium levels at seven months post-operation visit and was without complaint. Conclusions: To our best knowledge, this is the first reported case of RFA with IOPTH monitoring used to manage a parathyroid adenoma. Our work adds to the growing literature suggesting minimally-invasive techniques, such as RFA with IOPTH, as a potential management option for treating parathyroid adenomas.