title: Hypercalcemia due to giant cell myocarditis: a case report.
abstract: Granulomatous diseases are a rare cause of hypercalcemia. The pathogenesis is presumed to be from endogenous production of 1,25-dihydroxyvitamin D by activated macrophages in granulomatous lesions, which harbor the 1α-hydroxylase enzyme. Herein the first case of hypercalcemia associated with giant cell myocarditis, an unusual type of granulomatous process, is reported. In this case, a patient with giant cell myocarditis had development of progressive heart failure and cardiorenal syndrome that required biventricular support. One year later, hypercalcemia associated with a relatively high 1,25-vitamin D level and a concomitantly suppressed parathyroid hormone level developed in the presence of stage 4 chronic kidney disease. Her other workup of hypercalcemia was unrevealing for vitamin D intoxication and multiple myeloma. Computed tomography of her chest showed no signs of hilar lymphadenopathy. Her calcium levels returned to normal with low-dose steroid therapy and have remained normal following a successful heart transplant. This case illustrates an unusual cause of hypercalcemia thought to be due to extrarenal calcitriol production associated with giant cell myocarditis.
authors: Drexel University College of Medicine, Philadelphia, Pennsylvania.
authors: Ami M
authors: AM
authors: Patel
authors: Mariell
authors: M
authors: Jessup
authors: John
authors: J
authors: Tomaszewski
authors: Alden
authors: A
authors: Doyle
mesh_terms: D005260:Female; D015726:Giant Cells; D006099:Granuloma / Q000150:complications* / Q000473:pathology / Q000628:therapy; D016027:Heart Transplantation; D006801:Humans; D006934:Hypercalcemia / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology*; D008875:Middle Aged; D009205:Myocarditis / Q000150:complications* / Q000473:pathology / Q000628:therapy