Ectopic mediastinal parathyroid carcinoma presenting as acute pancreatitis

Abstract Parathyroid carcinoma is a rare cause of hyperparathyroidism, accounting for fewer than 1% of cases. The incidence of acute pancreatitis in patients with hyperparathyroidism was reported to be only 1.5%. We report a very rare case of ectopic mediastinal parathyroid carcinoma presenting as acute pancreatitis. A 72-year-old man presented with acute pancreatitis and hypercalcemia. During the work-up for hypercalcemia, a mediastinal parathyroid tumor was identified by 99m Tc-sestamibi scintigraphy and magnetic resonance imaging. The tumor was completely removed via a lower cervical collar incision. The histopathology revealed parathyroid carcinoma. There was no tumor recurrence or abdominal symptoms at 3-year follow-up.