Hypercalcemia is a frequent condition, especially in cancer patients, sometimes difficult
to diagnose because of its clinical presentation, mimicking other diseases. Severe elevation of serum
calcium generally gives mild and non-specific symptoms, ranging from fatigue, nausea, vomiting,
abdominal pain, and up to mental status deterioration and cardiac arrhythmias. It is crucial to
recognize acute hypercalcemia soon, and treat it aggressively. The severity of clinical findings
depends on both the calcium level and the rate at which it develops. The first line treatment is
massive rehydration with intravenous saline 0.9% to reach normovolemia, using invasive or noninvasive
monitoring. This helps eliminating calcium excretion in the urine. When hemodynamic
status or renal function is impaired, dialysis should be considered. Only when normovolemic status
is achieved and renal function restored, furosemide administration can help to further increase
urinary excretion of calcium. The second step is to inhibit osteoclastic bone resorption, which is
possible with both bisphosphonate and non-bisphosphonate drugs. After the emergency treatment, it
is important to diagnose and treat the underlying disease, such as hematological malignancy or other
malignancies, while patients with primary hyperparathyroidism should be considered for surgery
within a few days.
