A mysterious parathyroid adenoma

摘要

In 25% to 40% of persons, the inferior parathyroid gland is ectopically located along the long course of its embryologic descent from the third pharyngeal pouch. Ectopic parathyroid adenomas have been found in ret-roesophageal, retropharyngeal, and tracheoesophageal grooves; the mediastinum; the aortic arch; or, rarely, in the cervical carotid sheath (1). A 61-year-old man was evaluated for chronic mild hypercalcemia, osteopenia, stage 3 chronic kidney disease, and declining higher mental function. Laboratory testing revealed the following values: calcium, 11.2 mg/dL (8.4-10.7 mg/dL); phosphorus, 1.8 mg/dL (2.2-4.7 mg/dL); intact parathyroid hormone, 153 pg/mL (15-63 pg/mL); creatinine, 2.4 mg/dL (0.5-1.3 mg/dL); glomerular filtration rate, 34 mL/min/1.73 m~2 (90-125 mL/min/1.73 m~2); and calcium to creatinine clearance ratio, 0.01.