Rare Case of a Patient Presenting with Parathyroid Hormone-Related Peptide Mediated Hypercalcemia and IgG Heavy Chain Disease: Case Report and Review of Literature

• 作者: Chris Wunsch Damien Hansra Diaz Liege Ikpatt Offiong James E. Hoffman Victoria Sujoy
• 来源期刊: 血液病期刊(英文)
• 学科: 医学
• 关键词: HYPERCALCEMIA PARATHYROID Hormone-Related Peptide (PTHrP) FRANKLIN Disease Heavy Chain MYELOMA
• 年，卷（期）: 2015,（3）
• 页码范围: 31-38
• 页数: 8页
• 分类号: R73

摘要

IgG Heavy Chain Disease (γHCD) is a rare plasma cell disorder. Hypercalcemia related to plasma cell dyscrasias is related to non-PTHrP related mechanisms. Here we describe the first case of a patient with γHCD and PTHrP related hypercalcemia. Methods: Patient case derived from chart review from 2011 to 2015. Literature review performed searching PubMed 1968-current. Results: The patient was diagnosed with hypercalcemia with elevated PTHrP and exclusion of other etiologies of hypercalcemia. She was diagnosed with (γHCD) by M-spike 0.64 g/dL, IFE showing a broad band of IgG heavy chain, without associated light chains and severe depression of the non-mono-clonal IgG. Serum immunoglobulins demonstrated elevated IgG (2110 mg/dL), normal IgA (46 mg/dL) and decreased IgM (<21 mg/dL). Bone marrow biopsy showed 5% PCs, non-clonal by kappa/lambda, but exclusive for IgG by IHC, without any staining for IgA or IgM. The patient was started on therapy with improved hypercalcemia and PTHrP levels. Conclusions: This is the first reported case of γHCD presenting with PTHrP related hypercalcemia. Given that skeletal involvement is uncommon in γHCD, hypercalcemia secondary to γHCD may at times be a PTHrP driven phenomenon and we recommend that this test be ordered in such cases.