Hypercalcemia of Malignancy

Hypercalcemia of malignancy, a critical condition marked by serum calcium levels exceeding the upper reference limit, is a significant cause of morbidity and mortality among cancer patients, affecting 2–30% of the population diagnosed with cancer. This chapter delves into the etiology, clinical manifestations, diagnostic approach, and management strategies for hypercalcemia associated with malignancy. It highlights malignancy-associated hypercalcemia with a detailed examination of the mechanisms involved, including the secretion of parathyroid hormone-related protein, osteolysis induced by metastases, and the production of 1,25-dihydroxy Vitamin D by cancer cells. Clinical features, diagnostic protocols, and comprehensive management algorithms are presented to guide clinicians in effectively diagnosing and treating this oncological emergency. This chapter aims to equip healthcare professionals with the knowledge to promptly recognize and manage hypercalcemia of malignancy, thereby improving patient outcomes.