摘要
BACKGROUNDOver the past 20 years,we have gained a deep understanding of the biologicalheterogeneity of diffuse large B cell lymphoma(DLBCL)and have developed arange of new treatment programs based on the characteristics of the disease,bringing us to the era of immune-chemotherapy.However,the effectiveness andmolecular mechanisms of targeted-immunotherapy remain unclear in DLBCL.Targeted-immunotherapy may be beneficial for specific subgroups of patients,thus requiring biomarker assessment.CASE SUMMARYHere,we report a case of MCD subtype DLBCL with MYD88L265P and CD79Bmutations,considered in the initial stage as lymphoplasmic lymphoma(LPL)orWaldenstrom macroglobulinemia(WM).Flow cytometry supported this view;however,the immunohistochemical results of the lymph nodes overturned theabove diagnosis,and the patient was eventually diagnosed with MCD subtypeDLBCL.The presence of a monoclonal IgM component in the serum and infiltrationof small lymphocytes with a phenotype compatible with WM into the bonemarrow led us to propose a hypothesis that the case we report may have transformedfrom LPL/WM.CONCLUSIONThis highlights the possible transformation from WM to DLBCL,CD79B mutationmay be a potential biomarker for predicting this conversion.