Luo Xl

Clinicopathologic significance of immunophenotypic profiles related to germinal center and activation B-cell differentiation in diffuse large B-cell lymphoma from Chinese patients

Diffuse large B-cell lymphoma (DLBCL) can be subdivided into prognostically significant groups with germinal center B-cell-like (GCB), activated B-cell-like (ABC), and type 3 groups. In this study, tissue microarray slides composed of 163 de novo DLBCLs from Chinese patients were immunostained for CD20, CD10, Bcl-6, MUM1, CD138, Bcl-2, Ki-67, cyclin D3, geminin, and P27(Kip1). One hundred forty-nine of 163 DLBCLs could then be classified into GCB group (pattern A), activated GCB group (pattern B) and activated non-GCB group (pattern C) according to the expression of CD10, Bcl-6, MUM1, and CD138. Of the 149 cases, 40 (26%) showed pattern A expression and were grouped as GCB group, lower than reported frequency of the studies involving mostly Western population. Compared with cases with pattern A, those with pattern B (activated GCB group) and C (activated non-GCB group) more often presented with more aggressive tumors and a shorter survival time. These results indicate that most of DLBCLs from Chinese patients can be classified into prognostically different groups based on the antigenic expression models using a panel of GCB- and ABC-associated markers. Polymerase chain reaction analysis of t(14;18) showed that 11 of 64 cases were t(14;18)-positive, and most (10 of 11) of it occurred in the group with pattern A. The translocation was significantly associated with expression of Bcl-2 protein. The group with pattern B demonstrated more frequent expression of Ki-67, cyclin D3, geminin, and showed higher proliferative activity than the group with pattern A. These findings suggest that high proliferative activity of tumors with pattern B may be associated with aggressive tumor behavior and poor clinical outcome in patients with DLBCL.

Immunophenotypic features and t(14;18) (q32;q21) translocation of Chinese follicular lymphomas helps to distinguish subgroups.

BackgroundThe revised 2008 World Health Organization classification maintains a histological grading system (grades 1–3) for follicular lymphoma (FL). The value of grading FL has been debated. This study will yield deeper insights into the morphologic, immunophenotypic characterization and t(14;18) translocation in FL and explore their significance of diagnosis of Chinese FL subgroups.MethodsWe retrospectively reviewed the FL diagnoses according to the 2008 WHO classification in all diagnostic specimens from a multicentric cohort of 122 Chinese patients. Upon review, 115 cases proved to be truly FL. CD10, BCL6, MUM1, BCL2 and t(14;18) (q32;q21) translocation were detected by Envision immunostaining technique and fluorescence in situ hybridization.ResultsFL1 has larger proportion of follicular pattern (93.0%) than that of FL2 (73.7%, P = 0.036), FL3B (63.6%, P = 0.003) and FL3A (77.4%, P = 0.053), although the last P value was more than 0.05 (Pearson’s chi-squared test). Areas of DLBCL were present in 25.8% (8/31) of FL3A and more frequent in FL3B (59.1%, 13/22; P = 0.015). The positivity of CD10 and BCL2 in FL1-2 were significantly higher than those in FL3 (P < 0.001, P = 0.043, respectively). The positivity of MUM1 in FL1-2 was significantly lower than that in FL3 (10.2% vs. 51.0%; P < 0.001). Furthermore the positivity of MUM1 in FL3A was significantly lower than that in FL3B (37.9% vs. 68.2%; P = 0.032). The positivity of t(14;18) was higher in FL1-2 than in FL3 (73.5% vs. 35.6%, P < 0.001), and was higher in FL3A than in FL3B (51.9% vs. 11.1%, P = 0.005). t(14;18) was significantly correlated with CD10+ (R = 0.453, P < 0.001) and MUM1+ (R = -0.482, P < 0.001).ConclusionsFL1 and FL2 were immunophenotypically and genomically similar, while FL3A and FL3B were partly immunophenotypically similar but morphologically, genomically distinct. FL3A was genomically closer to FL1-2, whereas FL3A was genomically closer DLBCL. Thus we hypothesize that FL may in fact be a heterogeneous indolent lymphoma encompassing entities with distinct molecular pathogenesis and genetic characteristics. Immunohistochemical and genetic characterization helps to distinguish subgroups of FLs.Virtual slidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1334018129864616.