Diffuse large B-cell lymphoma: a heterogeneous group of non-Hodgkin lymphomas comprising several distinct clinicopathological entities.

Diffuse large B-cell lymphoma (DLBCL) as defined by the World Health Organization (WHO) classification is clinically, morphologically and genetically a heterogeneous group of malignant proliferations of large lymphoid B cells. Over the last 6 years, several studies have been published improving our understanding of these lymphomas. These studies analyzed DLBCL by their gene expression profile, provided further information on some of the variants of DLBCL listed in the WHO classification and stressed the impact of the site of origin of these tumors. This review summarizes these recent data and explores their impact on the recognition of new clinicopathological lymphoma entities.     

Comparison of peripheral T-cell lymphomas and diffuse large B-cell lymphoma

BACKGROUND: Peripheral T-cell lymphomas (PTCLs) are a biologically heterogeneous subgroup of lymphomas with poor prognosis. In this study, the authors analyzed the clinical behaviors of PTCLs and diffuse large B-cell lymphoma (DLBCL). METHODS: The authors compared the characteristics and outcomes of 59 patients with PTCLs, including 33 angioimmunoblastic T-cell lymphomas and 26 unspecified peripheral T-cell lymphomas, with the characteristics and outcomes of 193 patients with DLBCLs who were treated in the era before rituximab. RESULTS: Based on the clinical characteristics, elevated lactate dehydrogenase (LDH), poor PS, advanced stage, higher International Prognostic Index score, and B symptoms were more common in patients with PTCLs, and bulky mass was more common in patients with DLBCL. The rates of complete response (CR) or an unconfirmed CR (CRu) were higher in patients with DLBCL (72%) than in patients with PTCLs (56%; P = .03). The 5-year overall survival (OS), progression-free survival (PFS), and disease-free survival (DFS) rates were 31%, 26%, and 47%, respectively, in patients with PTCLs and 59%, 55%, and 73%, respectively, in patients with DLBCL (P = .001, P < .001, and P = .003, respectively). Although multivariate analysis identified several risk factors that were significant in PTCLs, but not in DLBCLs, for the CR/CRu, OS, PFS, and DFS rates, the immunophenotype was not identified as a risk factor. CONCLUSIONS: The poor response and survival of patients who had PTCLs, compared with patients who had DLBCL, was caused by numerous initial risk factors. T-cell phenotype itself did not appear to have a significant impact on either response or survival.     

T-cell/histiocyte-rich large B-cell lymphoma: a distinct clinicopathologic entity.

PURPOSE: Although it has proven difficult to delineate diagnostically reproducible and clinically relevant subgroups, the heterogeneity of diffuse large B-cell lymphomas (DLBCL) is widely acknowledged. In 1992, we reported on six cases that suggested that large B-cell lymphoma rich in stromal histiocytes and T cells may be identified as a distinct clinicopathologic entity within DLBCL. PATIENTS AND METHODS: An integrated clinicopathologic study of 40 cases of this DLBCL subtype is presented. RESULTS: Distinguishing a DLBCL rich in histiocytes and reactive T cells, designated T-cell/histiocyte--rich large B-cell lymphoma (THR-BCL), may be justified from a clinical point of view. The disease typically affects middle-aged male patients who usually present with advanced-stage disease that is not adequately managed with current therapeutic strategies. Whereas proliferation fraction and p53 overexpression, in addition to the clinical variables incorporated in the International Prognostic Index (IPI), significantly correlate with response to treatment and survival in a univariate analysis, only the IPI score identifies relevant prognostic THR-BCL subpopulations in a multivariate model. The morphologic and immunophenotypic profile of the neoplastic B cells in THR-BCL suggests that they may originate from a germinal center ancestor. CONCLUSION: THR-BCL constitutes a distinct clinicopathologic entity that is characterized by an aggressive behavior. Experimental therapeutic strategies may be indicated to obtain a more favorable response to treatment in this disease.     

High incidence of Kaposi sarcoma-associated herpesvirus infection in HIV-related solid immunoblastic/plasmablastic diffuse large B-cell lymphoma.

Kaposi sarcoma-associated herpesvirus (KSHV) is known to be associated with two distinct lymphoproliferative disorders: primary effusion lymphoma (PEL) and multicentric Castleman disease (MCD)/MCD-associated plasmablastic lymphoma. We here report a high incidence of KSHV infection in solid HIV-associated immunoblastic/plasmablastic non-Hodgkin's lymphomas (NHLs), in patients lacking effusions and without evidence of (prior) MCD. Within a cohort of 99 HIV-related NHLs, 10 cases were found to be KSHV positive on the basis of immunostaining for KSHV LNA-1 as well as KSHV-specific polymerase chain reaction. All but one of the tumors coexpressed Epstein-Barr virus. Interestingly, all KSHV-positive cases belonged to a distinctive subgroup of 26 diffuse large B-cell lymphomas characterized by the expression of CD138 (syndecan-1) and plasmablastic/immunoblastic morphology. These KSHV-positive lymphomas were preceded by Kaposi sarcoma in 60% of the patients and involved the gastrointestinal tract in 80%. Our results indicate that KSHV infection is not restricted to PEL and MCD; it is also common (38%) in HIV-related solid immunoblastic/plasmablastic lymphomas.     

Molecular pathogenesis of diffuse large B-cell lymphoma.

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous clinicopathologic entity accounting for 30% of non-Hodgkin's lymphomas. The pathogenesis of DLBCL is complex and heterogeneous. Recent studies using analysis of global gene expression with DNA microarrays and the classical molecular approaches demonstrate presence of several DLBCL subtypes characterized by different cells of origin, cytogenetic and molecular aberrations, and distinct pathogenesis. This review summarizes the progress in understanding of DLBCL biology and presents a state-of-the-art overview of DLBCL molecular pathogenesis.     

T-cell-rich B-cell lymphoma: a clinicopathologic study of 21 cases and comparison with 43 cases of diffuse large B-cell lymphoma

Clinicopathologic features of 21 patients with T-cell-rich B-cell lymphoma (TCRBCL) were reviewed and compared to 43 patients with diffuse large B-cell lymphoma (DLBCL) to determine if there were distinguishing clinical characteristics and differences in response or survival to CHOP therapy. For the diagnosis of TCRBCL, the current WHO criteria was used. In all of our cases, the majority of cells are non-neoplastic T cells and <10% large neoplastic B cells are present. The initial pathologic diagnosis was nodular lymphocyte predominant Hodgkin's lymphoma (NLPHL) in two cases. Patients with TCRBCL were significantly younger (median: 46 years) and had a significantly higher incidence of B symptoms (62%), hepatomegaly (33%) and marrow infiltration (33%) at presentation when compared to DLBCL (P<0.03). The CR rate after treatment was 48% for TCRBCL patients versus 79% for the DLBCL (P<0.003). Although the CR rates in between the two groups are significant, the difference in 3 years survival rates in each CR groups was insignificant (80% versus 77%). The overall survival time in the two groups was 17 months. Event-free survival time in TCRBCL was 12 months, compared with 17 months in the DLBCL (P>0.05). The frequency of patients with TCRBCL achieving CR was 52.6% whereas that of patients with DLBCL was 79% (P<0.003). The TCRBCL 3 years event-free survival 48% and overall survival 64% were 63 and 72% for DLBCL, respectively.     

Rituximab for the treatment of diffuse large B-cell lymphomas

For more than 25 years, the combination of cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) was considered the gold standard for the treatment of aggressive lymphomas, 90% of which are diffuse, large B-cell lymphomas (DLBCLs). Attempts to improve results by more intensive chemotherapy regimens, including high-dose chemotherapy approaches necessitating stem-cell support, have not convincingly shown improved outcome of DLBCL. The chimeric monoclonal antibody rituximab, which binds to the CD20 antigen expressed on normal B cells and the malignant cells of more than 90% of DLBCLs, and mediates lysis of these cells by direct induction of apoptosis, activation of complement- and antibody-dependent cellular cytotoxicity in vitro, is an attractive candidate for the treatment of B-cell lymphomas. Initial studies in follicular lymphoma demonstrated its efficacy as a single agent or in combination with chemotherapy without adding relevant toxicity. After the demonstration of rituximab single-agent activity in DLBCL, a pivotal trial in elderly patients demonstrated that combining rituximab with eight applications of CHOP significantly improved complete remission, event-free and overall survival rates when compared with CHOP alone. These positive results have meanwhile been confirmed by two additional randomized trials in elderly patients and have been extended to young patients with good-prognosis DLBCL by a fourth trial. While not yet formally established in young, poor-prognosis patients, rituximab in combination with CHOP has become accepted worldwide as the new standard for the treatment of DLBCL. Questions remain concerning the optimal dosage and schedule of rituximab for DLBCL, as well as the optimal chemotherapy regimen partner for rituximab. Rituximab is the first monoclonal antibody to consistently improve survival rates of patients with a malignant disease. Its excellent efficacy in combination with cytotoxic chemotherapy, together with its favorable toxicity profile, establishes rituximab as an indispensable component of modern standard immunochemotherapy of DLBCL.     

Rituximab for the treatment of diffuse large B-cell lymphomas

For more than 25 years, the combination of cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) was considered the gold standard for the treatment of aggressive lymphomas, 90% of which are diffuse, large B-cell lymphomas (DLBCLs). Attempts to improve results by more intensive chemotherapy regimens, including high-dose chemotherapy approaches necessitating stem-cell support, have not convincingly shown improved outcome of DLBCL. The chimeric monoclonal antibody rituximab, which binds to the CD20 antigen expressed on normal B cells and the malignant cells of more than 90% of DLBCLs, and mediates lysis of these cells by direct induction of apoptosis, activation of complement- and antibody-dependent cellular cytotoxicity in vitro, is an attractive candidate for the treatment of B-cell lymphomas. Initial studies in follicular lymphoma demonstrated its efficacy as a single agent or in combination with chemotherapy without adding relevant toxicity. After the demonstration of rituximab single-agent activity in DLBCL, a pivotal trial in elderly patients demonstrated that combining rituximab with eight applications of CHOP significantly improved complete remission, event-free and overall survival rates when compared with CHOP alone. These positive results have meanwhile been confirmed by two additional randomized trials in elderly patients and have been extended to young patients with good-prognosis DLBCL by a fourth trial. While not yet formally established in young, poor-prognosis patients, rituximab in combination with CHOP has become accepted worldwide as the new standard for the treatment of DLBCL. Questions remain concerning the optimal dosage and schedule of rituximab for DLBCL, as well as the optimal chemotherapy regimen partner for rituximab. Rituximab is the first monoclonal antibody to consistently improve survival rates of patients with a malignant disease. Its excellent efficacy in combination with cytotoxic chemotherapy, together with its favorable toxicity profile, establishes rituximab as an indispensable component of modern standard immunochemotherapy of DLBCL.     

Immunohistochemical identification of P-glycoprotein in previously untreated, diffuse large cell and immunoblastic lymphomas.

Expression of P-glycoprotein has been linked to multidrug resistance in cancer cell lines and human tumors. We investigated the frequency and clinical significance of P-glycoprotein immunoreactivity in 57 previously untreated diffuse large cell and immunoblastic lymphomas. Banked frozen tissue, which had been obtained prior to chemotherapy, was tested for reactivity with 2 monoclonal antibodies (MRK16 and C219) that recognize different domains of P-glycoprotein, using an immunoperoxidase technique. Thirteen of 57 lymphomas (23%) showed strong staining of greater than 50% of neoplastic cells; 15 of 57 (26%) showed labeling of a minority (11-50%) of neoplastic lymphocytes; 14 of 57 (25%) yielded equivocal results (reactivity in less than 10% of cells); and 15 of 57 (26%) were negative for P-glycoprotein. The 2 monoclonal antibodies were comparable in reactivity. Expression of MDR-1 mRNA was determined in 6 cases with sufficient available tissue, and did not correlate well with the percentages of cells reactive for P-glycoprotein by immunohistochemistry. Thirty-nine of our 57 patients completed multiagent chemotherapy. Contrary to our expectations, we found that P-glycoprotein immunoreactivity did not decrease the likelihood of response to induction chemotherapy. Median survival also was not adversely affected.     

弥漫大B细胞淋巴瘤CD5表达与临床病理特征及疗效关系的研究

目的:检测CD5蛋白在弥漫大B细胞淋巴瘤(DLBCL)的表达情况,并探讨CD5表达与临床病理特征及疗效的关系。方法:采用免疫组化方法(ElivisionTM法)检测232例患者中CD5蛋白的表达,回顾性研究CD5阳性表达DLBCL与CD5阴性表达DLBCL患者的临床病理特征及化疗效果,运用χ2检验比较两者差异。结果:232例DLBCL患者中,CD5阳性表达率19.8%(46/232)。DLBCL中,CD5表达与年龄(χ2=61.061,P=0.001)、性别(χ2=92.115,P=0.001)、分期(χ2=47.508,P=0.001)、KPS评分(χ2=42.178,P=0.001)、B症状(发热、乏力、盗汗和消瘦,χ2=56.344,P=0.001)、血清LDH水平(χ2=33.341,P=0.001)以及侵犯部位(χ2=78.123,P=0.001)相关;而与血清β2-MG水平无关,χ2=2.495,P=0.138。46例CD5表达阳性的患者中,6例化疗有效,有效率为13.0%(6/46);而186例CD5表达阴性DLBCL患者中,131例患者化疗有效,有效率为70.4%(131/186)。两者比较差异有统计学意义,χ2=50.227,P<0.05。结论:CD5阳性表达的DLBCL好发于老年女性,侵袭性高;CD5阳性表达DLBCL患者比CD5阴性表达的患者疗效差。     

Prognostic value of GST-pi expression in diffuse large B-cell lymphomas.

Among mechanisms potentially involved in resistance to alkylating agents and anthracyclines, the glutathione system has been extensively studied in vitro. We analyzed by immunohistochemistry the relation between glutathione s-transferase pi (GST-pi) expression in tumor cells and outcome in 69 cases of diffuse large B-cell NHL (DLBCL). GST-pi expression was considered as low when <50% of tumor cells were stained and high when >/=50% tumor cells were stained. Median follow-up was 58 months. GST-pi expression was correlated with the probability of achieving complete remission (CR). Patients with high GST-pi expression had a worse 5-year freedom from progression (FFP). High GST-pi expression was associated with a trend for lower survival. In the group of patients with International Prognostic Index (IPI) 0-1, low GST-pi expression was associated with a CR rate of 88%, a 5-year FFP of 76+/-20% and a 5-year survival of 78+/-16% compared to 36, 14+/-16 and 40+/-32%, respectively, in patients with a high GST-pi expression (P=0.002, P&<10(-5) and P=0.01, respectively). No correlation was found between GST-pi expression and lactico deshydrogenase serum level, age, Ann Arbor stage, performance status, and IPI index. Both GST-pi expression and the IPI index correlated with FFP. After incorporating IPI and GST-pi expression in a multivariate analysis for FFP, GST-p expression remained the only prognostic factor (P=0.003). Our findings suggest that GST-pi expression had strong prognostic significance in DLBCL, which appears to be independent of other prognostic parameters in those disorders.     

Diffuse large B-cell lymphoma of Waldeyer's ring has distinct clinicopathologic features: a GELA study

BackgroundDiffuse large B-cell lymphomas (DLBCLs) arising in specific extranodal sites have peculiar clinicopathologic features.Patients and methodsWe analyzed a cohort of 187 primary Waldeyer's ring (WR) DLBCLs retrieved from GELA protocols using anthracyclin-based polychemotherapy.ResultsMost patients (92%) had stage I–II disease. A germinal center B-cell-like (GCB) immunophenotype was observed in 61%, and BCL2 expression in 55%, of WR DLBCLs. BCL2, BCL6, IRF4 and MYC breakpoints were observed in, respectively, 3 of 42 (7%), 9 of 36 (25%), 2 of 26 (8%) and 4 of 40 (10%) contributive cases. A variable follicular pattern was evidenced in 30 of 68 (44%) large biopsy specimens. The 5-year progression-free survival (PFS) and the overall survival (OS) of 153 WR DLBCL patients with survival information were 69.5% and 77.8%, respectively. The GCB immunophenotype correlated with a better OS (P = 0.0015), while BCL2 expression predicted a worse OS (P = 0.037), an effect overcome by the GCB/non-GCB classification. Compared with matched nodal DLBCLs, WR DLBCLs with no age-adjusted international prognostic index factor disclosed a better 5-year PFS rate (77.5% versus 70.7%; P = 0.03).ConclusionsWR DLBCLs display distinct clinicopathologic features compared with conventional DLBCLs, with usual localized-stage disease, common follicular features and a high frequency of GCB immunophenotype contrasting with a low rate of BCL2 rearrangements. In addition, they seem to be associated with a better outcome than their nodal counterpart.     

T-cell/histiocyte-rich large B-cell lymphomas and classical diffuse large B-cell lymphomas have similar outcome after chemotherapy: a matched-control analysis.

PURPOSE: Because it is unclear whether T-cell/histiocyte-rich large B-cell lymphomas (H/TCRBCL) should be considered as a true clinicopathologic entity, we conducted a matched-control analysis comparing patients with H/TCRBCL and patients with diffuse large-B cell lymphoma (B-DLCL). PATIENTS AND METHODS: More than 4,500 patients were enrolled onto non-Hodgkin's lymphoma trials conducted by the Groupe d'Etude des Lymphomes de l'Adulte. After histologic review, 50 patients were subclassified as H/TCRBCL. They were matched to 150 patients with B-DLCL for each of the factors of the International Prognostic Index (IPI). RESULTS: Clinical characteristics of H/TCRBCL patients showed a male predominance and a median age of 47 years. Performance status was normal in 89% of patients, whereas lactate dehydrogenase level was increased in 60% of patients. The disease was disseminated in 81% of patients, and 48% had two or more involved extranodal sites. The IPI score was >or= 2 in 53% of patients. The complete response rate to chemotherapy was 63%, and 5-year overall survival (OS) and event-free survival (EFS) rates (mean +/- SD) were 58% +/- 18% and 53% +/- 16%, respectively. The matched-control analysis showed a trend toward a better response to chemotherapy for patients with B-DLCL (P =.06), whereas no difference was observed in OS (P =.9) and EFS (P =.8). CONCLUSION: H/TCRBCL is an aggressive disease that often presents with adverse prognostic factors. However, when treatment is adapted to the disease risk, outcome is equivalent to that observed in patients with B-DLCL. Thus H/TCRBCL should be considered a pathologic variant that belongs to the B-DLCL category.     

Diffuse intermediate lymphocytic lymphoma. A clinicopathologic study and comparison with small lymphocytic lymphoma and diffuse small cleaved cell lymphoma

Controversy has recently arisen as to whether diffuse intermediate lymphocytic lymphoma (ILL) should be considered a low-grade or an intermediate-grade non-Hodgkin's lymphoma for clinical purposes. Therefore, the authors performed a clinicopathologic study to determine the biologic course of diffuse ILL (40 cases) and compared it with small lymphocytic lymphoma (SLL; 51 cases) and diffuse small cleaved cell lymphoma (DSCCL; 14 cases). They found that patients with diffuse ILL having pseudofollicular proliferation centers (PC) had a significantly longer median survival (84 months) than those without PC (46.5 months; P = 0.03). The median survival of patients with SLL was 72 months, whereas those with DSCCL had a median survival of only 18 months. Based on these findings, the authors conclude that diffuse ILL with PC should be included in the low-grade category of SLL for clinical purposes, whereas diffuse ILL without PC (true diffuse ILL) should be considered an intermediate-grade non-Hodgkin's lymphoma. True diffuse ILL is similar to centrocytic lymphoma in the Kiel classification and should be accorded a similar status in a modified Working Formulation.     

Clinical relevance of the lung resistance protein in diffuse large B-cell lymphomas.

Drug resistance of non-Hodgkin's lymphomas may involve mechanisms of the multidrug resistance phenotype including the lung resistance protein (LRP) and the multidrug resistance protein (MRP1). To determine the clinical relevance of these multidrug resistance factors in previously untreated diffuse large B-cell lymphomas (n = 48), we studied LRP and MRP1 expression in lymphoma cells and their impact on clinical outcome. LRP and MRP1 expression were immunohistochemically assessed by means of the monoclonal antibodies LRP-56 and MRPr1, respectively. LRP was positive in 23% and MRP1 in 44% of the samples. LRP expression was associated with higher tumor stage (P = 0.03), elevated serum lactate dehydrogenase levels (P = 0.01), and the International Prognostic Index (P = 0.0001). LRP-positive patients had a lower complete response rate to polychemotherapy than LRP-negative patients (18 versus 65%; P = 0.006). Patients with LRP expression had a shorter overall survival than those without LRP expression (median of 0.9 years versus median not reached; P = 0.001). MRP1 expression was independent of clinical and laboratory parameters and had no impact on the outcome of chemotherapy or survival of the patients. These data suggest that LRP expression but not MRP1 expression is an important mechanism of drug resistance associated with worse clinical outcome in previously untreated diffuse large B-cell lymphomas. Thus, the reversal of LRP-mediated drug resistance may improve clinical outcome in diffuse large B-cell lymphoma in the future.     

弥漫性大B细胞淋巴瘤的临床特征及预后影响因素分析

目的　探讨弥漫性大B细胞淋巴瘤 (DLBCL)的临床特征及其预后的影响因素。方法回顾性分析 138例DLBCL患者的临床特征 ,结合随访资料 ,对DLBCL的预后影响因素进行单因素和多因素分析。结果　 87.7%侵犯淋巴结 ,6 0 .1%有结外侵犯 ,全组 5年生存率为 4 1.3%。多因素分析表明 ,患者年龄、临床分期和近期疗效是DLBCL预后的独立影响因素。国际预后指数 (IPI)计分低危组 5年生存率为 6 1.9% ,低中危组为 4 4 .3% ,高中危组为 2 0 .2 % ,高危组为 9.2 % ,差异有统计学意义(P <0 .0 1)。伴结外侵犯者 ,化疗联合手术治疗 5年生存率为 5 5 .6 % ,明显高于单纯化疗组。结论患者年龄、临床分期和近期疗效是DLBCL预后的独立影响因素 ,结外侵犯病例应采取手术和化疗联合治疗。     

Genetic and epigenetic determinants of diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common type of lymphoma and is notorious for its heterogeneity, aggressive nature, and the frequent development of resistance and/or relapse after treatment with standard chemotherapy. To address these problems, a strong emphasis has been placed on researching the molecular origins and mechanisms of DLBCL to develop effective treatments. One of the major insights produced by such research is that DLBCL almost always stems from genetic damage that occurs during the germinal center (GC) reaction, which is required for the production of high-affinity antibodies. Indeed, there is significant overlap between the mechanisms that govern the GC reaction and those that drive the progression of DLBCL. A second important insight is that some of the most frequent genetic mutations that occur in DLBCL are those related to chromatin and epigenetics, especially those related to proteins that “write” histone post-translational modifications (PTMs). Mutation or deletion of these epigenetic writers often renders cells unable to epigenetically “switch on” critical gene sets that are required to exit the GC reaction, differentiate, repair DNA, and other essential cellular functions. Failure to activate these genes locks cells into a genotoxic state that is conducive to oncogenesis and/or relapse.Subject terms: Diseases, Health care     

Among diffuse large B-cell lymphomas, T-cell-rich/histiocyte-rich BCL and CD30+ anaplastic B-cell subtypes exhibit distinct clinical features

Background:The EORTC clinical trial 20901, activated in1990, was designed to treat non-Hodgkins lymphomas (NHL) ofintermediate/high-grade malignancy according to the Working Formulation.Established in 1994, the R.E.A.L. Classification on NHL has now replacedall former classifications. Patients and methods:We reanalysed all cases (n=273) documented by material available for review according to theR.E.A.L. Classification. In addition, we subdivided cases recognised asdiffuse large B-cell lymphoma (DLBCL) into three morphologicallydistinct categories, namely, large cleaved DLBCL (LC-DLBCL),T-cell-rich/histiocyte-rich B-cell lymphoma (T-cell-rich/histiocyte-richBCL) and CD30+ DLBCL with anaplastic cell features (CD30+ DLBCL).Finally, T/NULL anaplastic large-cell lymphoma (ALCL) cases weresubdivided into ALK+ and ALK– lymphomas. Review was performedindependently by two pathologists from two different centres. Results:DLBCL (61%), T/NULL ALCL (15%) andmantle-cell lymphoma (MCL, 5%) were the main NHL categoriesrepresented in the study. Fifty-seven of one hundred sixty DLBCL caseswere further subclassified as LC-DLBCL (33 cases),T-cell-rich/histiocyte-rich BCL (13 cases) or CD30+ DLBCL (11 cases).The remaining cases were indicated as unspecified DLBCL. Aclinico-pathological correlation confirmed the findings of previousstudies suggesting that MCL, DLBCL and ALCL represent distinct entitieswith MCL being characterised by a short survival, in contrast with thelonger survival and less frequent progression typical of ALK+ comparedto ALK– ALCL. Within DLBCL, T-cell-rich/histiocyte-rich BCL showeddistinctive features at presentation whereas CD30+ DLBCL showed a trendtowards a more favourable prognosis, that might be comparable to that ofALK+ ALCL. Conclusions:Our data further support the usefulness of theR.E.A.L. Classification and illustrate the feasibility of DLBCLsubtyping. Moreover, our results demonstrate the distinct clinicalcharacteristics of T-cell-rich/histiocyte-rich BCL and CD30+ DLBCL withanaplastic cell features suggesting that they may representclinico-pathologic entities.