ABSTRACT
INTRODUCTION: Primary hyperparathyroidism (PHPT) is a common endocrine entity associated with increased parathyroid hormone (PTH) secretion. A single parathyroid adenoma is the cause of PHPT in the majority of cases. However, due to their embryological origin, discovery of ectopic parathyroid tissue is not extraordinary. CASE PRESENTATION: This is a case of a rare mediastinal parathyroid adenoma in a 56-year-old woman with emphasis on the preoperative diagnosis and accurate localization. CONCLUSION: Due to its small size and its various possible spots, ectopic parathyroid gland adenoma localization can be challenging. For this reason, careful preoperative mapping and surgical planning are essential before any exploration for parathyroid adenomas.
