[Polydipsia, increasing fatigue and a huge mediastinal tumor in a 49-year-old woman].

A 49-year-old woman presented with unspecific symptoms including polydipsia, increasing fatigue for several weeks, and vague abdominal pain. Serum calcium (5.30 mmol/l; normal range 2.00-2.60) and parathyroid hormone levels (> 2500.0 ng/l; normal range 15.0-68.0) were extremely elevated. Imaging studies showed a huge mediastinal tumor. Based on these findings a hypercalcemic crisis caused by primary hyperparathyroidism was diagnosed. After intensive care treatment and further diagnostic procedures, the patient's parathyroid adenoma was removed by parathyroidectomy. The postoperative course was uneventful.