title: [IgM myeloma].
abstract: The authors report the case of a 62 year old woman in whom bony pain led to the discovery of lacunar osteolytic appearances, in particular in the skull, abnormal medullary plasmacytosis and serum monoclonal immunoglobulin with Bence-Jones proteinuria. The case was unusual as the immunoglobulin observed was an IgM. This finding led the authors to a critical revision of the distinctive characteristics of multiple myeloma and Waldenström's macro-globulinemia, emphasizing the distinguishing value of the cytological criterion. The authors recall the various neoplastic proliferations of the B lymphocytes at the various stages of their maturation and emphasize the predominance of monoclonal IgM during proliferations affecting the early stages of maturation of the B lymphocytes and the rareness of these IgM during plasma cell neoplasms.
mesh_terms: D001402:B-Lymphocytes / Q000276:immunology; D001536:Bence Jones Protein / Q000652:urine; D001856:Bone Marrow Examination; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007075:Immunoglobulin M; D007145:Immunoglobulin kappa-Chains; D008875:Middle Aged; D009101:Multiple Myeloma / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D008258:Waldenstrom Macroglobulinemia / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology
chemical_list: D007075:Immunoglobulin M; D007145:Immunoglobulin kappa-Chains; D001536:Bence Jones Protein
vernacular_title: Myélome à IgM