Severe hypercalcemia as a form of acute lymphoblastic leukemia presentation in children

Hypercalcemia is a rare metabolic disorder in children and is potentially fatal. It has a wide differential diagnosis, including cancer. Here, we report the case of a previously healthy 3-year-old who was admitted to the emergency room with fatigue, hyporeactivity, fever and limping gait that had evolved over 5 days and that was progressively worsening. On examination the patient was unconscious (Glasgow coma score: 8). Laboratory tests indicated severe hypercalcemia (total calcium 21.39mg/dL, ionized calcium 2.93mmol/L) and microcytic anemia. Hyperhydration was initiated, and the child was transferred to the pediatric intensive care unit. Continuous venovenous hemodiafiltration with calcium-free solution was instituted, which brought progressive normalization of serum calcium and an improved state of consciousness. Zoledronate was administered, and metabolic and infectious causes and poisoning were excluded. The bone marrow smear revealed a diagnosis of acute lymphoblastic leukemia. Hypercalcemia associated with malignancy in children is rare and occurs as a form of cancer presentation or recurrence. Continuous venovenous hemodiafiltration should be considered in situations where there is imminent risk to life.