Hypercalcemia Associated with Eosinophilic Myocarditis in a Patient Undergoing Maintenance Hemodialysis

A 77-year-old man previously treated with maintenance hemodialysis was admitted due to appetite loss, nausea and shortness of breath. He showed progressive heart failure and eosinophilia without any basal disorders and was diagnosed with idiopathic hypereosinophilic syndrome (HES) accompanied by eosinophilic myocarditis. Laboratory data revealed hypercalcemia, a low serum parathyroid hormone level and a high 1,25(OH)2D concentration in spite of renal failure and no causal medications. Steroid therapy resulted in the patient's rapid recovery from heart failure, hypereosinophilia and hypercalcemia. Since the serum 1,25(OH)2D level promptly and markedly decreased, the hypercalcemia complicated with HES was most likely caused by extrarenal production of 1,25(OH)2D.