RESUMO
BACKGROUND Hypercalcemia, a serum calcium exceeding 10.5 mg/dL, is a multi-factorial metabolic disorder that results from an imbalance in calcium homeostasis. CASE REPORT We report a case of a 67-year-old male with recently diagnosed multiple myeloma who presented to our emergency department 3 weeks after COVID-19 infection with altered mental status and a fall. On admission he was found to have severe hypercalcemia with a level over 18.0 mg/dL. Despite IV fluids, calcitonin, steroids, and zoledronic acid, he had persistent, critically elevated calcium levels. The decision to initiate hemodialysis was made, which successfully treated his hypercalcemia. CONCLUSIONS This report presents a case of malignant hypercalcemia in an individual with COVID-19 and multiple myeloma and highlights the importance of considering dialysis as a viable treatment for hypercalcemia when other modalities have failed.