DLBCL with an associated IgM serum paraprotein (IgMs- DLBCL) has poor prognosis and frequent mutations in MYD88, CD79B and TP53 genes

PURPOUSE: to assess the clinicopathologic features of a poorly defined subset of diffuse large b-cell lymphoma, which is characterized by the secretion of an IgM paraprotein (IgMs-DLBCL). EXPERIMENTAL DESIGN: multicentre, retrospective, and comparative study to analyse with an integrated diagnostic approach the IgMs-DLBCL subset.RESULTS: Overall, 650 DLBCL were enrolled: 102 had an associated serum IgM and 56 other paraproteins (OP), the remaining 492 cases were the reference group (REF). IgMs-DLBCL were characterized by older age, advanced stage, dissemination to extra-nodal organs, elevated LDH and poor PS. As a result, the majority of IgMs had a high IPI, NCC-IPI and CNS-IPI score (p