[Differential diagnosis of primary hyperparathyroidism and malignancy-associated hypercalcemia]

If serum intact PTH levels are increased in hypercalcemic patients with malignant disorders, most likely diagnosis is malignant diseases associated with primary hyperparathyroidism. Ectopic PTH-producing tumors are extremely rare. When a patient with hypercalcemic crisis is admitted to emergency room, palpation of the neck and echographic examination of parathyroid tumors give most rapid and valuable findings. Laboratory data such as Ca, P, HCO3-, Cl, alkaline phosphatase and blood counts are of no value.