Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Case Reports
. 2025 May 30;71(2):E46-E49.
doi: 10.24546/0100495981.

A Rare Case of Pseudohypercalcemia Associated with Multiple Myeloma

Chiharu Mishima  1 , Kimikazu Yakushijin  1 , Hidenori Fukuoka  2 , Ruri Takahashi  1 , Yuri Okazoe  1 , Miki Joyce  1 , Sakuya Matsumoto  1 , Rina Sakai  1 , Yumiko Inui  1 , Keiji Kurata  1 , Hironobu Minami  1
Affiliations
Free article
Case Reports

A Rare Case of Pseudohypercalcemia Associated with Multiple Myeloma

Chiharu Mishima et al. Kobe J Med Sci. .
Free article

Abstract

We report a rare case of pseudohypercalcemia associated with multiple myeloma in a 77-year-old woman. Despite elevated albumin-corrected calcium levels (12.6 mg/dL), ionized calcium levels remained normal (1.25 mmol/L). Differential diagnoses excluded common causes of hypercalcemia, and the findings suggested calcium binding to negatively charged immunoglobulins and confirmed pseudohypercalcemia due to IgG-type myeloma. Treatment with isatuximab plus dexamethasone normalized albumin-corrected calcium levels as IgG levels decreased. This report highlights the importance of recognizing pseudohypercalcemia to prevent misdiagnosis of true hypercalcemia due to myeloma. Measuring ionized calcium levels is crucial for accurate diagnosis when hypercalcemia is suspected without corresponding clinical symptoms.

Keywords: Immunoglobulins; Ionized calcium; Multiple myeloma; Pseudohypercalcemia.

PubMed Disclaimer

Publication types