Case Report Life-Threatening Hypercalcemia due to Graves’ Disease and Concomitant Adrenal Failure: A Case Report and Review of the Literature Hande Mefkure Ozkaya, Fatma Ela Keskin, Ozlem Asmaz Haliloglu, Tugba Elif Senel, and Pinar Kadioglu Endocrinology and Metabolism, Cerrahpasa Medical School, University of Istanbul, 34098 Istanbul, Turkey Correspondence should be addressed to Pinar Kadioglu; kadioglup@yahoo.com Received 12 February 2015; Accepted 13 March 2015 Academic Editor: Yuji Moriwaki Copyright © 2015 Hande Mekure Ozkaya et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. A 47-year-old woman presented with the complaints of nausea, vomiting, and weight loss. She had a history of bilateral surrenalectomy due to Cushing’s syndrome. On examination she had tachycardia and orthostatic hypotension. Laboratory examinations revealed hypercalcemia and suppressed parathyroid hormone levels. She also had thyrotoxicosis due to Graves’ disease. he investigations to rule out a malignancy were negative. With steroid, zoledronic acid, and antithyroid drug treatment her symptoms were resolved and calcium level was normalized. his case highlights the importance of recognizing thyrotoxicosis and concomitant adrenal failure as a possible cause of severe hypercalcemia. 1. Introduction Severe or life-threatening hypercalcemia is, in most of the cases, either caused by neoplastic disease or primary hyper- parathyroidism [1]. However there are some other rare forms of hypercalcemia that can represent a diagnostic challenge to the physicians. Hyperthyroidism is known to cause a relatively mild hypercalcemia and elevated serum calcium levels are seen in approximately one-ith of the cases [2]. An increase in bone turnover and mobilization of calcium from bone into the circulation are the main mechanisms responsible for the hypercalcemia associated with hyperthy- roidism [3]. Concomitant conditions like hypocortisolism may aggravate hypercalcemia seen during hyperthyroidism and thyroid hyperfunction per se may induce a relative hypocortisolemic state, thus exacerbating further the degree of calcium elevation [4]. We herein report a case of 47-year- old woman presenting with life-threatening hypercalcemia due to Graves’ disease accompanied by acute adrenal failure. 2. Case Presentation A 47-year-old woman was admitted to our clinic with the complaints of nausea, intermittent vomiting, constipation, fatigue, and palpitation. She also had progressive weight loss of 10 kg since last 5 months. She had a history of bilateral surrenalectomy 3 years ago due to Cushing’s syndrome associated with adrenocorticotropic hormone (ACTH) inde- pendent macronodular adrenal hyperplasia. he patient was taking prednisolone 7.5 mg and ludrocortisone 0.1 mg orally once a day. Her family history was signiicant for breast cancer in her mother, gastric cancer in her aunt, and coronary artery disease in her uncle. Physical examination revealed tachycardia, presence of lid lag, warm skin, and orthostatic hypotension. he thyroid gland was enlarged and had a bruit. Pertinent laboratory values included a serum thyroid stimulating hormone (TSH) of 0.005 mIU/L (normal, 0.4 to 4.2) with a free T4 value of 7.7 ng/dL (normal, 0.93 to 1.7) and free T3 value of 16 pg/mL (normal, 2 to 4.4). hyroglobulin Hindawi Publishing Corporation Case Reports in Endocrinology Volume 2015, Article ID 684648, 5 pages http://dx.doi.org/10.1155/2015/684648