1,25-Dihydroxyvitamin D-mediated hypercalcemia in a patient with malignancy without lymphoma

Introduction: Hypercalcemia resulting from calcium homeostasis imbalance is seen in one-third of malignancies. Solid malignancies cause hypercalcemia from high parathyroid hormone-related peptide (PTHrP) and, infrequently, from osteolytic cytokines. Excessive 1, 25-dihydroxyvitamin D, seen mostly in lymphoma, causes hypercalcemia by 1-alphahydroxylation of 25-hydroxyvitamin D. This mechanism has also been reported in a few cases of dysgerminoma, myofibroblastic tumors, and gastrointestinal stromal tumors. Case Report: We present an unusual case of 1,25-dihydroxyvitamin D mediated hypercalcemia in a 62-year-old male with colonic adenocarcinoma and mesothelioma. Conclusion: This case emphasizes that elevated 1,25-dihydroxyvitamin D may be a hypercalcemia etiology in non-lymphoma malignancies and should to be considered when workup for elevated PTHrP and osteolytic hypercalcemia is negative. (This page in not part of the published article.) International Journal of Case Reports and Images, Vol. 6 No. 7, July 2015. ISSN – [0976-3198] Int J Case Rep Images 2015;6(7):403–406. www.ijcasereportsandimages.com Mastoris et al. 403 CASE REPORT OPEN ACCESS 1,25-Dihydroxyvitamin D-mediated hypercalcemia in a patient with malignancy without lymphoma Katie Mastoris, Sarah Park, Vasudev Magaji