[A case of temporary severe disequilibrium hypercalcemia].

The patient, a 69-year-old woman, was admitted to Osaka City University Hospital on July 25, 1992, for severe hypercalcemia. Laboratory data on admission revealed severe hypercalcemia of 14.9 mg/dl and renal dysfunction with serum creatinine of 2.9 mg/dl. As reflected by increased urinary excretions of pyridinoline and deoxypyridinoline and suppressed serum levels of parathyroid hormone (PTH) and 1,25-dihydroxyvitamin D, increased bone resorption seemed to be a main factor for the development of hypercalcemia. The development of hypercalcemia seemed to be acute because of (i) her severe symptoms caused by hypercalcemia and (ii) impaired renal function which improved after normalization of serum calcium. Following combination therapy of saline infusion and furosemide, there was a gradual decrease and later normalization of serum calcium together with serum creatinine. Even 8 months after discontinuation of the therapy for hypercalcemia, the serum calcium level has remained within the normal range. Measurement of serum factors which have hypercalcemia effects such as PTH, parathyroid hormone-related peptide and cytokines (interleukin-1 alpha, interleukin-1 beta, interleukin-2, interleukin-6 and tumor necrosis factor-alpha) were all within the normal range. In summary, hypercalcemia in this patient was regarded as a kind of disequilibrium hypercalcemia due to a combination of increased bone resorption and decreased renal capacity to excrete calcium. Furthermore, since it was temporary and has not recurred despite no treatment, her hypercalcemia developed due to imbalance in calcium regulation but not due to any organic disease.