Supernumerary Ectopic Mediastinal Parathyroid Adenoma Combined With Parathyroid Hyperplasia

Primary hyperparathyroidism (PHPT) is a common endocrine disorder characterized by elevated parathyroid hormone levels. In most cases, the disease involves a single parathyroid adenoma, followed by parathyroid hyperplasia, but the incidence of ectopic parathyroid adenoma is rare. However, in cases where the parathyroid hormone level remains high even after parathyroid surgery, an ectopic parathyroid gland should be considered. Here in a case of a 60-year-old female who presented PHPT is reported. She had undergone a surgical removal of the parathyroid gland of suspected hyperplasia, but still represented persistent PHPT, postoperatively. Ectopic mediastinal parathyroid adenoma was identified by 99mTc-sestamibi parathyroid scan and surgical excision via a median sternotomy approach was performed. Thirty-eight months postoperatively, there was no evidence of recurrence. Preoperative localization assessment is critical for minimizing surgical failure in cases of PHPT.