We report a case of a 66-year-old woman who developed hyperparathyroidism due to a large intrathyroid parathyroid adenoma with episodes of acute pancreatitis. She had previously been treated for acute pancreatitis twice. Serum calcium was 12.4 mg/dL, and intact parathyroid hormone was 253 pg/dL. Ultrasonography and computed tomography of the neck with contrast enhancement revealed a soft tissue...