Acute pancreatitis caused by an ectopic mediastinal parathyroid adenoma

A 22-year-old man was admitted to our hospital because of epigastric pain. Blood tests showed leukocytosis (8940 cells/mm³) and increased serum amylase levels (787 IU/L); an abdominal computed tomography (CT) scan revealed an enlarged pancreas and peripancreatic fluid collection. On the basis of these findings, he was diagnosed with acute pancreatitis. Hypercalcemia (13.5 mg/dL) and increased levels of parathormone (>3200 pg/dL) were also detected using a high-sensitivity assay; we therefore considered hypercalcemia and primary hyperparathyroidism to be the possible causes of the acute pancreatitis. A ^99mTc-sestamibi scan showed accumulation of parathyroid tissue in the left mediastinum, and a tumor was noted on the left side of the aortic arch on a thoracic CT scan. Our final diagnosis was acute pancreatitis due to hypercalcemia induced by an ectopic mediastinal parathyroid adenoma. Ectopic parathyroid tumors can thus cause acute pancreatitis, and ^99mTc-sestamibi and CT scans are useful for their diagnosis and localization.