Robot-Assisted Resection of a Superior Prevascular Mediastinal Ectopic Parathyroid Adenoma by Subxiphoid Approach: A Case Report.

INTRODUCTION

Ectopic mediastinal parathyroid adenoma is a rare cause of primary hyperparathyroidism, which is characterized by the excessive secretion of parathyroid hormone (PTH). Complete surgical resection is essential for curative treatment, making accurate intraoperative localization of the tumor a critical challenge. While superior mediastinal tumors have traditionally required invasive procedures such as median sternotomy, minimally invasive techniques, including video-assisted thoracoscopic surgery and robot-assisted surgery, have recently been adopted. However, in the lateral approach, visualization and instrument maneuverability beyond the left brachiocephalic vein are limited. In this case, we employed a robot-assisted subxiphoid approach combined with radio-navigation and intraoperative frozen section diagnosis for a superior prevascular mediastinal tumor adjacent to the jugular notch.

CASE PRESENTATION: An 82-year-old male was referred with primary hyperparathyroidism. Imaging, including 99mTc-methoxyisobutylisonitrile scintigraphy and contrast-enhanced CT, identified a 10-mm nodule in the superior prevascular mediastinum adjacent to the jugular notch. We performed a robot-assisted resection by subxiphoid approach using radio-navigation with a gamma probe and intraoperative frozen section diagnosis. The gamma probe was used to confirm the presence of target tissue in the excised specimen, and frozen section diagnosis confirmed that it was parathyroid tissue. The patient's intact PTH levels normalized immediately postoperatively.

CONCLUSIONS

The robot-assisted subxiphoid approach was feasible and provided an excellent surgical field for the superior prevascular mediastinum in this case. The combination of intraoperative radio-navigation and frozen section diagnosis is highly effective for ensuring the definitive resection of ectopic parathyroid adenomas.