Hypercalcemia accompanied by hypothalamic hypopituitarism, central diabetes inspidus and hyperthyroidism

We present here a case of prominent hypercalcemia accompanied by hypothalamic tumor and Graves' disease. A 24-year-old man with hypothalamic tumor showed hypopituitarism, central diabetes inspidus (DI) and hyperthyroidism. Nausea, loss of thirst and appetite, and general fatigue were found with the unveiling of hypercalcemia and hypernatremia. Parathyroid hormone (PTH) and 1alpha-dihydroxyvitamin D levels were suppressed with a normal range of PTH-related protein values. One-desamino-(8-D-arginine)-vasopressin (DDAVP) and half-saline administration normalized hypernatremia, while hypercalcemia was still sustained. Administration of cortisone acetate and thiamazole reduced the elevated serum Ca level. In the present case, concurrent hyperthyroidism was assumed to accelerate skeletal mobilization of calcium into the circulation. Hypocortisolism and central DI was also considered to contribute, to some extent, to the hypercalcemia through renal handling of Ca.