Ectopic mediastinal parathyroid adenoma: a cause of acute pancreatitis.

A 38-year-old male was admitted to our hospital with epigastric pain, and he was confirmed to have acute exudative pancreatitis. After the episode of acute pancreatitis subsided, laboratory investigation revealed increased serum calcium (12.0 mg/dl), decreased serum phosphorus (2.7 mg/dl), and increased serum parathyroid hormone (intact) levels (131 pg/ml). A computed tomography (CT) scan of the neck did not reveal any mass lesions in the parathyroid gland. However, (99m)Tc sestamibi scintigraphy revealed that there was one functioning parathyroid gland in the upper mediastinum. Combined (99m)Tc sestamibi scintigraphy and CT scan confirmed the diagnosis of primary hyperparathyroidism in the mediastinum. Microscopic examination revealed the presence of a parathyroid adenoma (1.3 x 0.4 cm(2)) adjacent to the atrophic parathyroid gland in right thymus gland. We report the case of a patient diagnosed with primary hyperparathyroidism due to an ectopic mediastinal parathyroid adenoma. An ectopic mediastinal parathyroid adenoma may manifest as an episode of acute pancreatitis. Preoperative investigation to determine the exact location of an adenoma should include two types of imaging studies, preferably (99m)Tc sestamibi scintigraphy and CT of the neck and chest.