Hypercalcemia and elevated serum 1.25-dihydroxyvitamin D in an end-stage renal disease patient with pulmonary cryptococcosis

Hypercalcemia occurs relatively often in dialysis patients. The most common cause of hypercalcemia in dialysis patients is the conventional therapy with calcium and calcitriol. Besides, secondary hyperparathyroidism, low turnover bone diseases, and immobilization are also common causes of hypercalcemia in dialysis patients. Fungal infection associated with hypercalcemia has been infrequently reported. We describe a 71-year-old female woman with end-stage renal disease and diabetes mellitus, who developed severe hypercalcemia. Pulmonary cryptococcosis, with increased concentration of serum 1,25-dihydroxyvitamin D (1,25(OH)₂D), was diagnosed. Her serum concentration of calcium and 1,25(OH)₂D returned to normal after antifungal treatment. Thus, hypercalcemia was mediated by extrarenal overproduction of 1,25(OH)₂D in this patient.