Thoracoscopic Resection of an Ectopic Mediastinal Parathyroid Adenoma Utilizing a Gamma Probe and Intraoperative Parathyroid Hormone Monitoring in a Child

Abstract

We herein report the case of a 13-year-old boy treated for an ectopic mediastinal parathyroid adenoma with thoracoscopic surgery utilizing a gamma probe and intraoperative parathyroid hormone (PTH) monitoring. The patient experienced repeated abdominal pain. An abdominal CT scan showed right hydronephrosis and a right ureter stone. His serum calcium level was elevated at 12.9 mg/dL and intact PTH was also elevated at 124 pg/mL. He was referred to our hospital for further examination and treatment. A 3D chest CT scan showed a high-density nodule in the anterior mediastinum region. 99mTc-sestamibi SPECT scanning revealed an increased uptake in the same region. Therefore, we highly suspected mediastinal parathyroid adenoma. We selected thoracoscopic resection because it is less invasive, uses a small incision, and results in less postoperative pain compared with sternotomy. Three ports were inserted: two 5.5 mm ports in the midaxillary line in the fourth and sixth right intercostal space and a 12 mm port for a gamma probe in the anterior axillary line in the sixth intercostal space. 99mTc-sestamibi (370 MBq) was injected 2 hours preoperatively. Radioactivity was measured over several areas using the gamma probe during surgery. ^1–2 The count rate over the area suspected to be parathyroid adenoma was 100 cps. However, the count rate over the surrounding tissue was 50 to 100 cps. We performed partial thymectomy because it was difficult to precisely determine the localization of the parathyroid tissue. The right lobe of the thymus including the area above the brachiocephalic vein and ascending aorta was resected. After resection of the adenoma, the count rate over the residual thymus tissue decreased. Conversely, the count rate over the ex vivo resected tissue was 50 cps. The preoperative intact PTH level was 154 pg/mL. Approximately 15 minutes after resection of the adenoma, the intact PTH level significantly decreased to 22 pg/mL. We confirmed complete resection of the mediastinal parathyroid adenoma. The postoperative course was uneventful. The patient's serum intact PTH level was maintained within the normal limits postoperatively. In conclusion, thoracoscopic resection of an ectopic mediastinal parathyroid adenoma is minimally invasive and safe for pediatric patients. Furthermore, intraoperative PTH monitoring is useful to confirm complete resection of the parathyroid adenoma.

No competing financial interests exist.

Runtime of video: 4 mins 52 secs