Systemic lupus erythematosus presenting as acute symptomatic hypercalcemia.

Hypercalcemia is a common electrolyte abnormality with a wide differential diagnosis. Primary hyperparathyroidism and malignancy are the most frequent causes, accounting for more than 90% of cases. We report the case of a woman presenting with symptomatic severe hypercalcemia, who was subsequently diagnosed with systemic lupus erythematosus (SLE) due to the presence of arthritis, lymphopenia, antinuclear antibodies (ANA), anti-DNA and anti-Ro antibodies and low C3 levels. After acute treatment with intravenous fluids, steroids, diuretics and pamidronate, calcium levels corrected and have remained normal on low-dose prednisone. Five similar cases have been reported in the literature. Thus, SLE is an uncommon cause of hypercalcemia, which can also be the presenting feature of lupus.