Treatment of acute lymphoblastic leukemia???induced extreme hypercalcemia with pamidronate and calcitonin

Objective To describe extreme hypercalcemia as the presenting feature of acute lymphoblastic leukemia in an 8-yr-old girl and the combined use of pamidronate and calcitonin for its treatment. Design Case report. Setting Pediatric intensive care unit. Patient An 8-yr-old girl with 20.0 mg/dL serum calcium (reference range, 8.8-10.4 mg/dL) and 2.66 mmol/L ionized calcium (reference range, 1.13-1.32 mmol/L). Intervention Intravenous pamidronate and subcutaneous calcitonin. Measurements and main results Our patient presented with nausea, vomiting, lethargy, weight loss, fatigue, and weakness but, remarkably, did not exhibit electrocardiographic changes. Initial treatment with hydration at 8 mL x kg(-1) x hr(-1) and furosemide was ineffective. A single dose of 1 mg/kg intravenous pamidronate given over 24 hrs complemented by three doses of 5 units/kg subcutaneous calcitonin over 36 hrs lowered serum calcium to a normal range within 3 days. Side effects noted were hypocalcemia, hypomagnesemia, and hypophosphatemia. They were most pronounced 7-9 days after treatment, stabilized with supplementation, and returned to acceptable ranges by 1 month without need for ongoing electrolyte supplements. A renal computed tomographic scan did not show nephrocalcinosis. The patient remained free from recurrence of hypercalcemia 6 wks after initiating chemotherapy for acute lymphoblastic leukemia. Conclusions Extreme hypercalcemia can be a presenting feature of acute lymphoblastic leukemia, but it may not result in life-threatening organ dysfunction. Combined treatment with pamidronate and calcitonin should be considered for treating hypercalcemia that does not respond to conventional therapy with hydration and furosemide.