Approach to diagnosis and treatment of hypercalcemia in a patient with malignancy.

Hypercalcemia is a common complication of malignancy and portends a worse prognosis. It causes a variety of symptoms in patients, which can range from confusion and polyuria to coma and death. There are 4 broad mechanistic categories to classify hypercalcemia of malignancy: local osteolysis secondary to metastatic cancer or multiple myeloma, excess parathyroid-related hormone, excess 1,25-dihydroxyvitamin D production, and ectopic parathyroid hormone production. Volume expansion with normal saline solution and treatment with intravenous bisphosphonates to decrease osteoclast-mediated bone destruction are effective initial therapies. Calcitonin, gallium nitrate, and corticosteroids can serve as adjunctive therapies. Denosumab is an attractive therapeutic option for refractory cases of hypercalcemia, although more data are required before this therapy can be recommended.