1. A case of severe 1,25-dihydroxyvitamin D-mediated hypercalcemia due to a granulomatous disorder
- Author
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Charles Chan, Katherine Ann Benson, Jane Tong Wen Zhang, and Sun Young Kwun
- Subjects
medicine.medical_specialty ,Sarcoidosis ,Endocrinology, Diabetes and Metabolism ,Clinical Biochemistry ,Malignancy ,Biochemistry ,chemistry.chemical_compound ,Endocrinology ,Internal medicine ,Biopsy ,Hypercalcemia Therapy ,medicine ,Vitamin D and neurology ,Humans ,Vitamin D ,Histiocyte ,Aged ,Granuloma ,medicine.diagnostic_test ,Myositis ,business.industry ,Biochemistry (medical) ,medicine.disease ,chemistry ,Giant cell ,Proximal Muscle ,Hypercalcemia ,Female ,Cholecalciferol ,business - Abstract
Profound hypercalcemia is usually due to underlying malignancy.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 1α-hydroxylase activity.Biopsy of the vastus lateralis muscle showed extensive granulomatous myositis. Immunohistochemical staining for 1α-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.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.
- Published
- 2012