Pseudohypercalcemia in a patient with multiple myeloma and acute kidney injury; a case report

Abstract

Here in this paper, we present a 60-year-old man admitted for generalized pain in his limbs and was finally diagnosed with multiple myeloma. He also underwent evaluation and treatments for his hypercalcemia (15 mg/dL). His calcium concentration did not respond well to different modalities and was along with a low parathyroid hormone (PTH) and elevated creatinine concentration (12 mg/dL). Further evaluations revealed normal ionized calcium which confirmed the diagnosis of pseudohypercalcemia. Multiple myeloma is a plasma cell neoplasm in which 10% of the patients suffer from true-hypercalcemia at the time of diagnosis. Pseudohypercalcemia is described as an elevated serum calcium concentration along with normal ionized calcium concentration and the absence of clinical symptoms of hypercalcemia. The cause of pseudohypercalcemia in multiple myeloma is due to the binding of calcium to increased abnormal immunoglobulins. The importance of this issue lies in the low PTH levels along with hypercalcemia and azotemia which is suggestive of pseudohypercalcemia.

Keywords: Pseudohypercalcemia, Multiple myeloma, Plasma cell neoplasm, Hypercalcemia, Glomerular filtration rate, Acute kidney injury