A Case of Severe 1,25-Dihydroxyvitamin D-Mediated Hypercalcemia due to a Granulomatous Disorder

作者：Zhang Jane Tong Wen^*; Chan Charles; Kwun Sun Young; Benson Katherine Ann

来源：Journal of Clinical Endocrinology & Metabolism, 2012, 97(8): 2579-2583.

DOI：10.1210/jc.2012-1357

Background: Profound hypercalcemia is usually due to underlying malignancy.
Case: We describe a case of granulomatous myositis presenting with extreme hypercalcemia of 20.1 mg/dl and generalized weakness that did not resolve despite rapid correction of serum calcium. The disease process was unmasked by cholecalciferol supplementation. Initial search for a malignant process yielded no diagnosis, but an elevated 1,25-dihydroxyvitamin D level, in the setting of a suppressed PTH and undetectable PTHrP, pointed to the presence of excessive 1 alpha-hydroxylase activity.
Methods and Results: Biopsy of the vastus lateralis muscle showed extensive granulomatous myositis. Immunohistochemical staining for 1 alpha-hydroxylase was localized to the multinucleated giant cells and histiocytes. Musculoskeletal magnetic resonance imaging showed involvement of proximal muscle groups of both thighs and upper limbs.
Conclusion: Measurement of vitamin D metabolites is pivotal in diagnosing 1,25-dihydroxyvitamin D-mediated hypercalcemia. Granulomatous disease can occasionally cause profound hypercalcemia and needs to be considered in the differential diagnosis. 1,25-Dihydroxyvitamin D-mediated hypercalcemia is responsive to glucocorticoid therapy. (J Clin Endocrinol Metab 97: 2579-2583, 2012)

• 出版日期2012-8