pubmed-article:12649152 | pubmed:abstractText | Patients with diffuse large B-cell lymphoma (DLBCL) rarely show relapse after 4 years of complete remission (CR). In this study, we addressed the following questions: (1) Does late-relapsing DLBCL represent clonally related disease or a second malignancy; and (2) is there a characteristic biologic background? In 10 of 13 DLBCL patients with relapse after 4 to 17 years, a clonal relationship was established based on identical IgH-sequences and/or identical bcl2-IgH translocation. Most (77%) showed features of germinal center (GC) cells, as defined by expression of CD10, bcl-2, and bcl-6 protein and ongoing immunoglobulin heavy chain variable region (VH) hypermutation. A GC phenotype was seen in 8 (20%) of 38 control patients matched for age, stage, and (extra)nodal localization with relapse within 2.5 years (P =.005). In conclusion, we have found evidence that late-relapsing DLBCL represents truly clonally related disease episodes in most cases and that this clinical behavior may be related to the biologic features of GC cells. | lld:pubmed |