Unlike conventional DLBCL, PMB-DLBCL exhibits distinct clinicopathological features, including involvement without nodal/extramedullary disease, higher incidence of pancytopenia due to marrow infiltration, subtle presentation without palpable masses, and enriched MYD88 L265P mutations, which necessitate tailored diagnostic and therapeutic approaches. This evidence concerns the gene MYD88 and diffuse large B-cell lymphoma.