Challenging diagnosis of IgM multiple myeloma

BMJ Case Rep. 2024 Jan 4;17(1):e253328. doi: 10.1136/bcr-2022-253328.


IgM monoclonal gammopathies such as IgM myeloma and Waldenström macroglobulinaemia are distinct haematological conditions; however, differentiating between these entities can often present as a challenge.In this review, we explore the challenging diagnosis and treatment of IgM myeloma in a patient presenting with unexplained macrocytic anaemia, elevated serum protein and IgM levels in the absence of t(11;14) and lytic bone lesions that are classically associated with the diagnosis of IgM myeloma. The diagnosis was established based on 40% monoclonal plasma cell population on a bone marrow biopsy, gain of 1q21 on fluorescence in situ hybridisation, cyclin D1 positivity and absence of MYD88 mutation.

Keywords: Cancer intervention; Haematology (drugs and medicines); Haematology (incl blood transfusion); Malignant and Benign haematology; Malignant disease and immunosuppression.

Publication types

  • Case Reports

MeSH terms

  • Bone Marrow / pathology
  • Humans
  • Immunoglobulin M
  • Multiple Myeloma* / pathology
  • Plasma Cells / pathology
  • Waldenstrom Macroglobulinemia* / genetics


  • Immunoglobulin M