Clinical Insights Into Hypercalcemia of Malignancy in Childhood

Hypercalcemia of malignancy (HCM) is a rare but life-threatening metabolic emergency in children that occurs in less than 1% of pediatric cancer cases, with a reported incidence ranging from 0.4% to 1.0% across different studies. While it is observed in 10%-20% of adult malignancies, pediatric HCM remains relatively uncommon. Unlike HCM in adults, in which solid tumors are the primary cause, pediatric HCM is most frequently associated with hematological malignancies such as acute lymphoblastic leukemia (ALL). Knowledge regarding the duration of malignancy-related hypercalcemia is obtained by evaluating the increasing trend in calcium levels at clinical visits, which provides information about the stage and prognosis of the malignancy. Suddenly developing, symptomatic and severe hypercalcemia indicates a poor prognosis in patients with malignancy. In this narrative review, we discuss the distinct pathophysiological mechanisms and clinical presentation of HCM in children and the current therapeutic strategies.