A case report of primary hyperparathyroidism due to a giant substernal parathyroid adenoma managed using a neck incision approach.

RATIONALE: Primary hyperparathyroidism is an endocrine disease primarily caused by a single benign parathyroid adenoma. It is characterized by symptoms such as hypercalcemia, hypophosphatemia, kidney stones, and bone destruction. Parathyroid adenomas are generally located on the posterior aspect of the thyroid gland, while giant parathyroid adenomas in the anterior superior mediastinum are relatively rare. Typically, benign anterior superior mediastinal tumors are managed through sternotomy or thoracoscopic surgery, which can be associated with significant trauma or complications. PATIENT CONCERNS: We present a case of a patient with hypercalcemia and hyperparathyroidism. Biochemical analysis showed that the serum calcium level was 2.72 mmol/L and the parathyroid hormone level was 1050 pg/mL. Physical examination, ultrasound, and CT scans revealed a lesion in the right anterior superior mediastinum, suggesting it originated from the right inferior parathyroid gland. DIAGNOSES: Based on the physical examination, biochemical, and imaging findings, the patient was preliminarily diagnosed with a parathyroid tumor in the right anterior superior mediastinum. INTERVENTIONS: The patient underwent successful resection of a giant anterior superior mediastinal parathyroid adenoma via a neck incision. OUTCOMES: At the 1-year follow-up, the patient was alive and had normal voice function. There was no abnormal increase in serum calcium or parathyroid hormone levels. LESSONS: For certain benign anterior superior mediastinal tumors, a neck incision is recommended to minimize surgical trauma and promote faster postoperative recovery.