[Hypocalcemia in malignant diseases]

Hypercalcemia accompanies often malignant diseases. The majority of cases of malignancy complicated by hypercalcemia is induced by metastases involving bone, hypercalcemia may also accompany localised tumors. Various hormones have been implicated in the genesis of malignant hypercalcemia: ectopic secretion of parathyroid hormone by tumor or orthotopic secretion by concomitant primary hyperparathyroidism, prostaglandin activating osteoclasts, production of hypercalcemic factor other than these hormones. This review summarizes current knowledge about endocrine-mediated mechanisms which produce hypercalcemia and about its frequency and mechanism in different types of tumors.