Primary Hyperparathyroidism Presenting with Dysphagia Due to a Large Parathyroid Adenoma: A Case Report

Background: Primary hyperparathyroidism (PHPT) is most commonly caused by a solitary parathyroid adenoma, whereas compressive symptoms from large adenomas are uncommon. This report describes an unusual presentation with dysphagia. Methods: A 66-year-old woman with one month of progressive dysphagia and approximately 10 kg of weight loss underwent gastroenterological and otorhinolaryngological assessment, contrast-enhanced computed tomography, ultrasonography, biochemical testing, and parathyroid hormone (PTH) washout. Results: Endoscopy and flexible fiberoptic examination did not identify a cause of dysphagia. CT demonstrated a 3.0 × 1.9 × 4.7 cm heterogeneous cervical mass extending toward the superior mediastinum and displacing adjacent structures. Total calcium was 3.02 mmol/L, ionized calcium 2.60 mmol/L, and serum PTH 365.1 pg/mL. PTH washout exceeded 3438 pg/mL. Surgical excision and histopathology confirmed a parathyroid adenoma. Postoperative PTH decreased to 58.4 pg/mL and dysphagia resolved completely. Conclusions: A large parathyroid adenoma should be considered in patients with unexplained dysphagia, particularly when hypercalcemia and elevated PTH are present.