Unclassifiable B-cell Lymphoma Research Articles

Clinical Features and Treatment Outcomes of Grey Zone Lymphoma (GZL), Unclassifiable B-Cell Lymphoma with Features Intermediate between Diffuse Large B-Cell Lymphoma and Classical Hodgkin Lymphoma - a Real-Life Multicenter Study By the Croatian Cooperative Group for Hematologic Diseases (KroHem)

GZL with features between classical Hodgkin lymphoma (HL) and diffuse large B-cell lymphoma (DLBCL) is a rare entity originally introduced in the 2008 World Health Organization (WHO) classification. GZL has been included in KroHem Lymphoma Treatment Guidelines since 2012. The recommended treatment was induction with escalated BEACOPP (escBEACOPP) in those below 60 y and ABVD in those above 60 y, both in combination with rituximab (R) and consolidation with radiotherapy (RT) for patients with limited or autologous stem cell transplantation (ASCT) in those with advanced-stage disease. We conducted a comprehensive retrospective analysis of GZL patients treated in KroHem centers to evaluate clinical features, treatment outcomes and prognostic factors. GZL diagnoses were confirmed by a hematopathologist from a designated expert center, according to current WHO classification at time of diagnosis. Twenty-three patients were evaluable for analysis, 20 diagnosed de novo, and 3 in relapse (2 after HL, 1 after DLBCL). Fourteen patients (60%) were male; median age was 39 and range 18-78 y. Thirteen (57%) presented with mediastinal GZL (MGZL) and 10 (43%) with non-MGZL (NMGZL). NMGZL patients were older (median 55 versus 31 y, p = 0.0157) and had more frequently high NCCN-IPI scores (9/10 vs 5/13, p = 0.0288). Twelve front-line patients received R-escBEACOPP, 4 DA-R-EPOCH, 1 R-ABVD and 3 R-CHOP-like regimen. Of the 3 patients diagnosed in relapse, 2 were treated with R-ICE and 1 with R-CHOP. Ten patients were irradiated and 9 underwent ASCT as consolidation in 1 st remission. Stem-cell collection was successful in all planned patients, albeit 70% with plerixafor. Sixteen (80%) front-line patients responded to immunochemotherapy, 2 progressed during consolidation. At the end of treatment, 13 patients were in complete and 1 in partial remission for a response rate of 70%. Of the 3 relapsing patients, 2 treated with R-ICE responded, underwent ASCT and are in continuous remission. One patient died of toxicity after ASCT in 1 st remission. After a median survivors follow-up time of 42 months, 6 front-line patients have died and additional 3 progressed. Overall survival (OS) at 4 y is 65% and event-free survival (EFS) 52%. MGZL and NMGZL patients had similar outcomes; OS at 4 y was 69% and 64% (p=0.637) and EFS 52% vs. 50% (p=0.88) respectively. Performance status was a statistically significant prognostic factor (OS at 4 y ECOG grade 0-1 90% vs. ECOG grade 2-4 17%, p<0.001; EFS at 4 y 67% vs. 17% p=0.044). Sex influenced EFS (male 70%, female 33% at 4 years, p=0.050), but not OS (69% vs. 61% p=0.667). Age (< 60 y >), presence of bulky or extranodal disease, stage, anemia, LDH or B2M level did not significantly influence outcomes. Patients treated with R-escBEACOPP had numerically superior outcomes (OS at 4 y 81% vs. 44%, p=0.167; EFS at 4 y 64% vs 38%, p=0.293). Despite the small number of patients, the difference was statistically significant in patients with MGZL; EFS at 4 y was 71% in the group treated with R-escBEACOPP vs 0% in the group treated with other regimens (p=0.021) and OS 100% vs. 0% (p<0.001). In contrast, patients with NMGZL treated with R-escBEACOPP had numerically inferior outcomes in comparison to those treated with other regimens (p=0.127 for OS and p=0.388 for EFS). In conclusion, our data confirm the validity of differentiating between MGZL and NMGZL. MGZL patients might benefit from aggressive therapies designed for HL, such as escBEACOPP, in combination with rituximab. Consolidation with ASCT is feasible, but most patients will need plerixafor to collect sufficient stem cells. Different regimens, as used for DLBCL, should be preferred in NMGZL patients.

Evolution in the definition and diagnosis of the Hodgkin lymphomas and related entities.

Hodgkin lymphoma was the first of the lymphomas to be recognized as a specific disease entity. However, recent studies have highlighted the heterogeneity of the diseases associated with this eponym warranting clarification and refinement of diagnostic terminology. While classic Hodgkin lymphoma (CHL) remains an essentially unchanged diagnostic entity in the 2022 International Consensus Classification of Mature Lymphoid Neoplasms (2022 ICC), nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) is now renamed nodular lymphocyte predominant B cell lymphoma (NLPBL) in recognition of the distinct pathologic, biologic, and clinical differences. Fan patterns A, B, and C (sharing the presence of evident follicular structures, and retention of a B cell rich background) will be combined in "typical" or grade 1, while the other "variant" patterns, D, E, and F, are considered grade 2. T-cell/histiocyte-rich large B cell lymphoma (THRBCL) is considered part of the "variant" NLPHL continuum.The entity previously known as "B cell lymphoma, unclassifiable (BCLU), with features intermediate between diffuse large B cell lymphoma (DLBCL) and CHL" has been renamed "mediastinal gray zone lymphoma" (MGZL) in recognition of the importance of the thymic niche in the biology of this tumor. The diagnostic criteria for MGZL have been refined and require both a high tumor cell density and a strongly preserved B cell program.This article will describe updates on CHL, NLPBL, and MGZL in the recently published 2022 ICC and provide some useful differential diagnostic clues in cases with atypical morphology or immunophenotype.

Treatment of B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and classical Hodgkin’s lymphoma (gray zone lymphoma) in children and young adults: a case series

B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma (DLBCL) and classical Hodgkin’s lymphoma (cHL) is a rare malignant disease that develops from mature B cells. This disease was first recognized as a distinct entity in 2008. It is most common in the 20 to 40 age group and rare in children. Currently, there are no clear criteria for diagnosis and standard therapy for such patients. According to the literature, it is possible to use treatment regimens applied for both aggressive B-cell lymphomas and Hodgkin's lymphoma. The addition of anti-CD20/CD30 targeted agent to standard therapy may be effective, given the expression of these markers by tumor cells. In this article, we present the clinical and morphological characteristics of patients with unclassifiable B-cell lymphoma with features intermediate between DLBCL and cHL, diagnosed at our center, including 4 patients at the onset of the disease in childhood. Patients and/or their legal representatives have consented to the use of information, including photographs, in scientific research and publications.

Rituximab Concentration Varies in Patients With Different Lymphoma Subtypes and Correlates With Clinical Outcome.

Individual variations in concentrations of rituximab in different B cell non-Hodgkin’s lymphoma subtypes and their relevance to efficacy were still unclear. From 2016 to 2021, a prospective clinical trial was conducted, and 510 samples with 6 uncommon subtypes of B-cell lymphoma were enrolled to examine the pharmacokinetic behaviour of rituximab and its impact on clinical outcomes, including complete response (CR), progression-free survival (PFS) and overall survival (OS). Considerable variability was observed in the rituximab trough concentration in the first cycle (C1-trough, 1.16–55.52 μg/ml) in patients with different lymphoma subtypes. Patients with “double-hit” lymphoma (4.01 ± 0.77 μg/ml) or mantle cell lymphoma (MCL; 15.65 ± 16.45 μg/ml) had much lower C1-trough and worse outcomes. Great individual variation in the C1-trough existed among patients with mucosa-associated lymphoma (MALT), and the high C1-trough observed in patients treated with the RB regimen was associated with a better response than was obtained with R-CHOP (38.41 ± 14.13 μg/ml vs 15.49 ± 8.80 μg/ml, p = 0.0029). Despite the high aggressiveness of the cancer, Burkitt lymphoma patients receiving intensive chemotherapy had the highest C1-trough (28.85 ± 9.35 μg/ml) and maintained long-term PFS. The C1-trough in patients with mixed, unclassifiable B-cell lymphoma was close to 20 μg/ml, and these patients had acceptable outcomes. Overall, a low rituximab C1-trough was associated with adverse consequences, including persistent progression, early recurrence and a short OS, however, some high-risk factors appeared to be balanced by the presence of a high C1-trough. Basal levels of circulating CD19+ lymphocytes differed between and within patients with diverse lymphoma subtypes and were negatively correlated with C1-trough. Therefore, the traditional doses of rituximab are inadequate for patients with “double-hit” lymphoma and MCL. Increasing the initial rituximab dose according to the disease, high-risk factors and even the baseline CD19+ lymphocyte count will be new methods to optimize therapeutic regimens for patients with different lymphoma subtypes.

Screening Strategy for Detecting Double-Hit Lymphoma in a Resource-Limited Setting

High-grade B-cell lymphomas with MYC and BCL2 and/or BCL6 rearrangements [double-hit lymphomas (DHL)] are aggressive lymphomas. Current literature recommends fluorescent in-situ hybridization analysis (FISH) in all cases of diffuse large B-cell lymphoma (DLBCL) to identify cases of DHL. However, this approach is not feasible in a resource-limited setting. We analyzed cases of de novo high-grade B-cell non-Hodgkin lymphoma using histomorphology, immunohistochemistry and FISH to identify which cases need to undergo FISH testing in a resource-limited setting. Cases of de novo high-grade B-cell non-Hodgkin lymphoma that included DLBCL, not otherwise specified and B-cell lymphoma unclassifiable (BCLU) with features intermediate between DLBCL and Burkitt lymphoma diagnosed over a period of 5 years were analyzed by Hans algorithm, MYC, BCL2, and Ki67. MYC, BCL2, and BCL6 break apart FISH was tested in selected cases. One hundred and nine cases were obtained, of which 102 had DLBCL morphology and 7 had BCLU/blastoid morphology. BCL2 expression was noted in 48 cases (44%), MYC in 33 cases (30.3%) and MYC/BCL2 co-expression in 24 cases (22%). FISH testing could be done in 42 consecutive cases, of which 5 cases had MYC and BCL2 co-rearrangement (11.9%) (double-hit) and 2 cases showed rearrangement for only MYC (4.7%) (single-hit). Single-hit lymphoma/DHL showed significant independent positive correlation with BCLU/blastoid morphology, CD10 expression, germinal center B-cell phenotype, and MYC/BCL2 co-expression. The sensitivity and specificity of each parameters include BCLU/blastoid morphology (42% vs. 94%), CD10 positive (50% vs. 88%), germinal center B-cell phenotype (57% vs. 82%), MYC/BCL2 co-expression (85% vs. 80%). Selected candidates for FISH (any one of the above parameters) using this strategy showed a sensitivity and specificity of 100% and 68%, respectively (P=0.001). We propose a highly sensitive screening strategy for detection of MYC/BCL2 rearrangement in high-grade B-cell lymphoma in a resource-limited setting (pending validation in a larger cohort).

Characteristics of rheumatoid arthritis with immunodeficiency-associated lymphoproliferative disorders to regress spontaneously by the withdrawal of methotrexate and their clinical course: A retrospective, multicenter, case-control study.

To investigate clinical characteristics and time course of lymphoproliferative disorders (LPDs) in rheumatoid arthritis (RA) patients after methotrexate (MTX) discontinuation, in those who achieved spontaneous regression (SR). We retrospectively reviewed clinical data from RA patients with LPDs obtained from eight institutions between 2000 and 2017 and compared clinical and pathological findings between SR and non-SR groups. Among 232 RA patients with LPDs, 216 were treated with MTX at the onset of LPD and 144 (66.7%) achieved SR after MTX discontinuation. Higher MTX doses, high titers of anti-CCP antibodies (>13.5 U/mL), and lower LDH and soluble IL-2 receptor levels were associated with SR. Lymphocyte count was decreased at LPD onset and increased at 2 weeks after MTX discontinuation in the SR group. Epstein-Barr virus-positive mucocutaneous ulcer, reactive lymphoid hyperplasia and unclassifiable B-cell lymphoma, were more frequent in the SR than in the non-SR group. In multivariable analysis, diffuse large B-cell lymphomas was an independent predictive factor for non-SR. In the patients with SR, 73.9% achieved partial or complete regression as early as 2 weeks after MTX discontinuation. SR and non-SR in RA patients with LPDs after MTX discontinuation were associated with certain clinical characteristics.

Generalizability of Landmark Clinical Trials in Diffuse Large B Cell Lymphoma to Real-World Patients: A Single-Centre Retrospective Cohort Study

Background: Clinical trials are the gold standard by which therapies in oncology are evaluated and ultimately form the bases for approval of novel therapies. Stringent eligibility criteria limit the participation of many "real-world" patients and thus undermine the generalizability of trial results. Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of Non-Hodgkin lymphoma (NHL) and is curable in the majority of patients treated with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone). The addition of rituximab to CHOP is the only clear advancement in DLBCL therapy in the last 20 years. Though a large minority of patients are not cured by R-CHOP, several subsequent novel therapies have failed to demonstrate benefit in Phase 3 clinical trials. We hypothesized that real world patient populations differ from clinical trial populations with trial eligibility excluding the poor-outcome patients who might benefit most from novel therapy. Methods: We performed a retrospective chart review of all patients 18 years of age or older who were registered within the Alberta Cancer Registry with a new diagnosis of pathology-confirmed DLBCL, between January 1, 2010 and December 31, 2011. Clinical characteristics were reviewed to assess patient eligibility to participate in 3 landmark clinical trials for DLBCL on the basis of inclusion and exclusion criteria defined by each study. The trials included Pfreundschuh, M. et al. (2006) and Coiffier, B. et al. (2002), which were assessed together as representing the landmark studies for rituximab added to CHOP, and the GOYA trial (2017) which evaluated obinutuzumab-CHOP vs R-CHOP. Categorical variables are presented as frequencies and percentages. Univariate probabilities of overall-survival were calculated by Kaplan-Meier method. Results: We identified 480 patients with a diagnosis of DLBCL within the Alberta Cancer Registry. A total of 390 patients were eligible for our study with 20 patients excluded for CNS lymphoma, 29 for unclassifiable B-cell lymphoma, 2 patients who died at the time of diagnosis, and 25 patients with previously treated indolent lymphoma. In addition, 14 patients were excluded for insufficient clinical data. Table 1 demonstrates the clinical characteristics of the population. Out of 390 patients, only 130 (33%) patients met inclusion for the rituximab studies and 134 (34%) for the GOYA study. Table 2 demonstrates the most common criteria leading to trial exclusion, including poor performance status, limited stage disease, inappropriate IPI, transformed lymphoma, history of second primary malignancy, and viral infections. Trial ineligible patients had significantly inferior overall survival compared to trial eligible patients (Figure1). Conclusions: The majority of real-world DLBCL patients are excluded from clinical trials and have inferior outcomes compared to trial eligible patients. The selection of patients with more favourable outcomes for clinical trials may contribute to failure to demonstrate a benefit of novel therapies. Broadening inclusion criteria to include patients with transformed disease and poor performance status could aid in improving the generalisability of DLBCL clinical trials. Disclosures Stewart: Gilead: Honoraria; Roche: Honoraria; Celgene: Honoraria; Amgen: Honoraria; Abbvie: Honoraria; Janssen: Honoraria; Teva: Honoraria; Sandoz: Honoraria; AstraZeneca: Honoraria; Novartis: Honoraria. Owen:AbbVie, F. Hoffmann-La Roche, Janssen, Astrazeneca, Merck, Servier, Novartis, Teva: Honoraria.

A Case Of Vena Cava Superior Syndrome With Lymphoma

Vena cava superior syndrome (VCSS) defines the deterioration in blood circulation as a result of an obstruction in vena cava superior (VCS) and the resulting clinical condition. It might develop due to various reasons including malign and benign ones. Because of swelling on the face and neck, 38 year-old woman was undergone thoracic computed tomography. Pleural effusion was observed in right hemithorax and a mass applying pressure on the vena cava superior on the middle mediastinum. Pet-CT was taken; prevascular lymphadenopathies with SUDmax: 21.1 were observed. The frozen result of mediastinoscopy was reported to be necrosis. Thoracotomy was implemented; the pathologic formation thought to be thrombus in the lumen of vena cava superior was excised. At the end of pathological examination, this mass was reported to be unclassified b-cell lymphoma having the characteristics of Burkitt’s and large-cell lymphoma. The patient was given chemotherapy. The remission was achieved. In our case, the reason for VCSS was intravascular thrombus-shaped large B-cell lymphoma. This case was presented because it is a rare reason for VCSS.

Unclassifiable B-cell lymphoma with features intermediate between diffuse large B-cell lymphoma and classical Hodgkin lymphoma in an AIDS patient. Report of a case and literature review

Unclassifiable B-cell lymphoma with features intermediate between diffuse large B-cell lymphoma and classical Hodgkin lymphoma in an AIDS patient. Report of a case and literature review

Clinical Features of Post-Transplant Lymphoproliferative Disease Are Different between Kidney-Transplant Recipients from a Cadaveric Donor and Those from a Living Donor

Background: The number of solid organ transplantation (SOT) is increasing. While the remarkable improvement in SOT procedures provides recipients with a good chance of long-term survival, the prolonged immunosuppression has led toa variety of malignancies in solid organ transplant (SOT) recipients; post-transplant lymphoproliferative disorder (PTLD) is a life-threating complication among them. However, there remain some controversies regarding its clinical features. Method: We retrospectively surveyed the patients who had visited both departments: hematology and urology, or renal surgery in kidney center at Tokyo Women's Medical University Hospital from 2003 to 2017. We identified 61 patients diagnosed with hematological disorder in kidney-transplant recipients. Among them, PTLD were analyzed. Continuous variables were compared using Student's t-tests. Overall survival rate (OS) was calculated using the Kaplan-Meier method. P values < 0.05 were considered significant. Statistical analyses were performed using JMP Pro 14 (SAS Institute Inc., Cary, NC, USA) and GraphPadPrism version 7.0 (GraphPad Software, San Diego, USA). This study was conducted in accordance with the Declaration of Helsinki and approved by the institutional review boards. Results: During the survey period, 3,133 patients had visited both departments: hematology and urology, or surgery in Kidney Center. Among them, 61 kidney-transplant recipients were diagnosed with hematological disorder; they comprised 27 PTLD, 10 plasmacytic disorder, 6 idiopathic thrombocytopenic purpura, 5 myelodysplastic syndromes, 4 acute leukemia, 3 polycythemia, 6 other diseases. Among the patients with PTLD (n = 27), 18 patients (66.7%) were male.Median patient ages at the diagnosis of PTLD and kidney transplant were 54 (25-79) and 43 (16-75) years, respectively. Eighteen and nine patients had received kidney-transplant from a living donor (15 related and three unrelated donors) and a cadaveric donor, respectively. The median time from kidney transplant to diagnosis of PTLD was 7.8 years; there was a significant difference in the time between the kidney-transplant recipients from a cadaveric donor and those from a living donor (Figure 1A, 11.3 and 5.6 years, P = 0.02). With regard to the histological subtypes of PTLD, they comprised 17 diffuse large B-cell lymphoma (63.0%), 2 Burkitt lymphoma (7.4%), 4 unclassified B-cell lymphoma (14.8%), 2 T-cell lymphoma (7.4%), and 2 unknown cases (7.4%). 24 of 27 patients had extranodal involvement: 9 central nervous system (33.3%), 7 gastrointestinal tract (25.9%) and other sites. First-line treatment procedure which all patients received was the modification of immunosupressants; complete response (CR) rate was 37.0%. After the failure of first-line therapy, 15 of 27 patients received chemotherapy: 4 rituximab monotherapy (30.8%), 6 CHOP-like regimens (46.2%), and other regimens (33.3%). Among them, five patients experienced relapse. They received salvage chemotherapy, and 2 and one patients achieved CR and partial response, respectively. Rest of them died of lymphoma and infection. The estimated five-year OS from the diagnosis of PTLD and the initiation of chemotherapy was 88.7% and 86.7%, respectively. During the survey period, 5 patients died; their causes of death were 3 lymphomas, 1 infection, and 1 heart failure. There were no deaths in kidney-transplant recipients from a cadaveric donor (Figure 1B). Discussion: While our cohort had more extranodal PTLD recipients than those reported previously, the modification of immunosupressants improved them in more than one-third of cases, which showed the usefulness of it as first-line treatment procedure for PTLD. Nearly half of cases were identified in recipients from a cadaveric donor; the results suggest that the incidence o PTLD among them is higher than those from a living donor because the number of kidney-transplant from a living donor was 10 times higher than those from a cadaveric donor. This study has several limitations due to its retrospective nature and small sample size. In addition, the estimated five-year OS might be better than actual because some patients became lost to follow-up. Further large-scale studies are warranted to validate the findings of this study. Disclosures Hagiwara: Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees. Tanaka:Bristol-Myers Squibb: Research Funding.

Abstract 3702: Establishment and characterization of a novel MYC/BCL2 double-hit high-grade B-cell lymphoma cell line HLA-3

Abstract The majority of MYC/BCL2 double hit lymphoma (DHL) morphologically resembles diffuse large B-cell lymphoma (DLBCL) or unclassified B-cell lymphoma, with intermediate features of DLBCL and Burkitt’s lymphoma. DHL also typically results in shorter survival time than other lymphomas. To further understand DHL’s biology and identify potential effective agents against DHL, we established a unique MYC/BCL2 high-grade B-cell lymphoma cell line with morphological DLBCL features. The HLA-3 DHL cell line was derived from a MYC/BCL2 high-grade B-cell lymphoma patient-derived xenograft (PDX) model. We performed flow cytometry immunophenotypic analysis and established the HLA-3 cell line after 7 months of continuous culture. We utilized molecular and cellular techniques, including flow cytometry and polymerase chain reaction (PCR) analysis, to characterize the HLA-3 cell line. We performed reverse phase protein array (RPPA) analysis to determine its protein signaling profile. To identify agents with anti-DHL activity, we screened the effects of a panel of agents alone and in combination with ibrutinib on the cell viability of this newly established cell line. The HLA-3 cell line was optimally maintained at a density between 1 and 2 × 106 cells/mL and successfully proliferated in a single-cell suspension without cellular clump formation. The HLA-3 cells were EBV-negative and possessed a germinal center B cell immunophenotype. Moreover, the immunophenotypes of the primary patient tumor cells and HLA-3 cells were virtually identical. The HLA-3 cells were positive for CD19, CD45, CD35, CD10 and HLA-ABC, negative for CD3, CD5, CD40, CD34 and TdT, and were dim for CD22, CD56, CD8, CD4 and CD23. Representative flow cytometry histograms showed 99% of the HLA-3 cells were positive for CD19 and CD45, with no detectable surface kappa and lambda light chains. The HLA-3 cells expressed a high level of CD38, an indicator of MYC rearrangement. Similar to the original lymphoma cells, the HLA-3 cells showed dim/low CD20 expression. Based on RPPA data, we constructed a diagram showing activation of the ATM/Chk2 DNA repair and the IGF1R/PI3K/mTOR signaling pathways in the HLA-3 cells. In support of this upregulated activity, we found that 5/7 tested commercial PI3K/mTOR inhibitors significantly reduced the viability of the HLA-3 cells in a dose-dependent manner, with AZD8055 the most sensitive of the tested inhibitors against the cell line. Further, DNA repair pathway inhibitors BMN673 and RG7112 were effective against the HLA-3 cell line. The newly characterized high-grade B-cell lymphoma cell line will provide useful in vitro and in vivo models for biological studies related to human DHL, which is refractory to current therapies and urgently needs novel therapeutic approaches. This work suggests the PI3K/mTOR and DNA repair pathways may be therapeutic targets for MYC/BCL2 double-hit high-grade B-cell lymphoma. Citation Format: Hui Guo, Hui Zhang, Krystle Nomie, Liang Zhang, Kelley P. Murfin, Michael Wang. Establishment and characterization of a novel MYC/BCL2 double-hit high-grade B-cell lymphoma cell line HLA-3 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3702.

Aggressive B-cell lymphomas—from morphology to molecular pathogenesis

The2016 revised World Health Organization (WHO) classification of lymphoidmalignancies recognizes several distinct entities within the group of diffuselarge B-cell lymphoma (DLBCL) characterized by unique clinical and pathologicalfeatures. Nevertheless, diffuse large B-cell lymphoma, not otherwise specified(DLBCL, NOS) is the most common aggressive B-cell lymphoma. In the last 20 yearsour understanding of the genetic changes and biology of DLBCL has increasedtremendously. According to the 2016 WHO classification, the diagnosis of DLBCL,NOS, should include cell of origin (COO); germinal centre B-cell (GCB) oractivated B-cell (ABC)/non-GCB subtypes, because of their different molecularfeatures, biologic behavior, prognosis and treatment. High-grade B-celllymphoma (HGBL) with MYC and BCL2 and/or BCL6 rearrangements (i.e., double-hit or triple-hit lymphoma, DHL or THL) as well asHGBL, NOS, are two new categories in the 2016 revised WHO classification thatsubstituted the provisional category of B-cell lymphoma, unclassifiable (BCLU)with features intermediate between DLBCL and Burkitt lymphoma (BL), which wasintroduced in the 2008 WHO classification. The pathogenesis and molecularchanges of BL are better understood and led to the recognition of a newprovisional entity called Burkitt-like lymphoma with 11q aberration. In thisarticle, we will review the progress made in the last years within the mostcommonly encountered aggressive B-cell lymphomas, highlighting the betterunderstanding of the underlying disease mechanisms that eventually might be translatedinto more rational and effective therapeutic strategies. Controversial issuesabout fluorescent in situ hybridization (FISH) for the detection of MYC , BCL2 and BCL6 translocations will be addressed, as well as newmolecular techniques used to improve diagnosis and prognostication inaggressive B-cell lymphomas.

Najważniejsze zmiany w diagnostyce agresywnych chłoniaków z komórek B według klasyfikacji Światowej Organizacji Zdrowia z 2017

In 2017, the revised 4 th edition of the classification of tumors of hematopoietic and lymphoid tissues developed by the World Health Organization was introduced. Some of the significant changes concern the updating of data covering biology, pathomorphology, genetics and clinical features of aggressive lymphomas from mature B cells. New entities have been introduced (high grade B-cell lymphoma and Burkitt-like lymphoma with 11q aberration), some of existing ones have beenmodified (EBV-positive diffuse large B-cell lymphoma, not otherwise specified) and some provisional ddefinitions (unclassified B-cell lymphoma, with intermediate features between diffuse B-cell lymphoma and classic Hodgkin’s lymphoma) have been retained. Significant progress in the field of molecular biology techniques and genetics translates into their practical use in the routine diagnosis of lymphomas. Currently, the correct diagnosis of high-grade B-cell lymphoma in addition to pathomorphological and immunohistochemical diagnosis requires the determination of status C-MYC , BCL2 and BCL6 genes. This is a significant challenge for the reorganization of routine diagnostics. This is influenced by limited availability of standardized molecular/genetic techniques and determination of funding for these studies. The most important factor still remaining is the involvement of a specialized team of doctors and technicians ensuring adequate collection, protection of biological material and its development by various techniques, which translates into the possibility of issuing a full result including proper diagnosis.

Analysis of the Clinicopathological Characteristics, Treatment and Prognosis of Unclassifiable B-Cell Lymphoma Intermediated between DLCBL and BL

To analyze the clinicopathological characteristics, treatment and prognosis of patients with unclassifiable B-cell lymphoma intermediated between DLCBL and BL. A total of 16 patients with DLBCL/BL in our hospital were included in this study between July 2014 and June 2016. The clinical and pathological data of 16 patients were collected. Kaplan-Meier method was used to estimate and compare overall survival (OS) and progression-free survival (PFS). The log-rank test was used to analyze the influence of age, sex, B symptoms, LDH level, lymyhoma staging, KPS score, Ki-67(%), extranodal sites, IPI score, β2 microglobulin level, DPLs, tumour cell origin and treatment etc. Results: Fifty out of 16 patients showed extra-nodal involvement among the 16 patients with DLBCL/BL. The median OS and PFS times were 11 and 7 months respectively. The one year OS and PFS rates were 50.0% and 43.8% respectively. The borderline difference between the CHOP, CHOP-like, and intensive chemotherapy groups is statistically significant(P=0.067). Univariate analysis showed that IPI score and LDH were significant prognostic factors for the overall survival of the patients with DLBCL/BL. DLBCL/BL is a highly aggressive B-cell lymphoma with a short survival time. DLBCL/BL responded better to intensive chemotherapy than CHOP or CHOP-like regimen. IPI score and LDH level are significant prognostic factors for the overall survival of the patients with DLBCL/BL.

High-throughput sequencing of nodal marginal zone lymphomas identifies recurrent BRAF mutations

Nodal marginal zone lymphoma (NMZL) is a rare small B-cell lymphoma lacking disease-defining phenotype and precise diagnostic markers. To better understand the mutational landscape of NMZL, particularly in comparison to other nodal small B-cell lymphomas, we performed whole-exome sequencing, targeted high-throughput sequencing, and array-comparative genomic hybridization on a retrospective series. Our study identified for the first time recurrent, diagnostically useful, and potentially therapeutically relevant BRAF mutations in NMZL. Sets of somatic mutations that could help to discriminate NMZL from other closely related small B-cell lymphomas were uncovered and tested on unclassifiable small B-cell lymphoma cases, in which clinical, morphological, and phenotypical features were equivocal. Application of targeted gene panel sequencing gave at many occasions valuable clues for more specific classification.

Первинна В-клітинна лімфома стравоходу, некласифікована, з проміжними характеристиками між дифузною В-великоклітинною лімфомою і класичною лімфомою Годжкіна у пацієнта зі синдромом Дауна

Первинна В-клітинна лімфома стравоходу, некласифікована, з проміжними характеристиками між дифузною В-великоклітинною лімфомою і класичною лімфомою Годжкіна у пацієнта зі синдромом Дауна

Diagnosis and Clinical Analysis of Primary Thyroid Lymphoma.

Objective To summarize our experiences in the diagnosis and prognosis of different subtypes of primary thyroid lymphoma (PTL). Methods The clinical data of 27 PTL patients who were treated in our hospital from January 1998 to December 2014 were retrospectively analyzed. The pathological types of these patients included B cell lymphoma unclassifiable (BCLU) (n=5),mucosa-associated lymphiod tissue lymphoma (MALT) (n=9),diffuse large B cell lymphoma (DLBCL) (n=12),and T cell lymphoma (n=1). Results Of all these 27 cases,the most common clinical symptom was painless swelling of the neck (n=21,77.8%). Of 7 patients who had received preoperative fine needle biopsy,lymphoma was suspected in 2 cases (28.6%). Among these 7 cases,the positive rate of suspicious lymphoma was 66.7% in 3 DLBCL patients,0 in 3 MALT patients,and 0 in 1 BCLU paitent. Also,25 patients underwent intraoperative frozen pathological examination,which revealed lymphoma or suspicious lymphoma in 16 cases (64.0%); in these patients,the positive rate was 66.7% for BCLU,77.8% for MALT,58.3% for DLBCL,and 0 for T-cell lymphomas. The overall survival was (89.3±12.4) months,and the overall 5-year survival rate was 61.6%. The estimated survival in symptomatic group was 31.6 months,which was significantly shorter than that in asymptomatic group (97.9 months) (P=0.032). Other factors including age,sex,tumor size,tumor stage,international prognostic index,tracheal compression,lactate dehydrogenase,residual tumor,and pathological type showed no significant effect on survival(all P>0.05). Conclusions DLBCL has the highest fine needle biopsy positive rate,MALT has the highest frozen pathological positive rate,and intraoperative frozen pathology has more malignant results than the preoperative fine needle biopsy in the diagnosis. The accompanying lymphoma symptoms may be an adverse prognostic factor.

Treatment of aggressive B-cell lymphomas.

Treatment of aggressive B-cell lymphomas.

Unfavorable Prognostic Impact of MYC Increased Copy Number (ICN) in Patients with Diffuse Large B-Cell and High-Grade Lymphoma Treated with Immuno-Chemotherapy (ICT)

Background: MYC rearrangements occur approximately in 5-15% of diffuse large B-cell lymphoma (DLBCL), and are known to unfavorably impact on patients (pts) survival, especially if associated to BCL2 or/and BCL6 rearrangements (double/triple-hit). Previous studies have shown that also a MYC gene ICN may confer a worse prognosis to these pts (Yoon, Histopathology 2008), but only few groups have transferred this observation into the clinical practice. However, this finding may account for those cases that, despite the absence of MYC rearrangements, show a similar aggressive clinical course. For this reason, a careful study of all aberrations involving MYC geneshould be widely applied. We report a single center experience on the clinical outcome of pts with MYC ICN in the setting of aggressive B-cell lymphoma.Methods: In the study period (Aug 2011-Aug 2015) we performed FISH analysis in all consecutive pts with de novo or transformed DLBCL or B-cell lymphoma, unclassifiable (BCLU) that displayed Ki67 >80% or intense bcl2 protein expression. Interphase FISH has been performed on 23 μm thick sections of formalin fixed paraffin embedded tissues, using splitsignal DNA probes (Dako) specific for the following loci: 8q24 (MYC), 18q21 (BCL2) and 3q27 (BCL6). For each sample, 60 evaluable nuclei with complete FISH signals were scored. ICN was considered when 3 or more copies of the gene studied were identified.Almost all pts with a MYC translocation have been treated according to Burkitt lymphoma (BL)-like regimens as first line therapy (FLT); pts with MYC ICN have been treated with BL-like regimens from 2013, whereas standard ICT (R-CHOP or R-CHOPlike) has been used for these pts diagnosed before 2013. Overall survival (OS) was evaluated by Kaplan Meier method.Results: In the 4-year study period, 317 consecutive pts were diagnosed with de novo or transformed DLBCL or BCLU. Twenty-one (7%) showed a translocation of MYC, in single (14%), double (67%) or triple hit (19%), with respect to BCL2 and BCL6 rearrangements. Interestingly, 8 (2.5%) pts with no MYC translocation showed MYC ICN, ranging from 3 up to 10 gene copies per cell. This aberrant gene copy number was observed in > 80% of the analyzed nuclei in 7 cases. The characteristics of the pts with MYC gene rearrangement or ICN are summarized in Table 1.Of the 8 pts with MYC ICN, 5 had de novo DLBCL, 2 had transformed DLBCL and 1 had BCLU. Seven pts also showed BCL2 and/or BCL6 rearrangement/ICN. Three pts were treated with standard ICT and 5 with a BLlike regimen. Two pts (25%) responded to the FLT, showing one complete and one partial remission (CR and PR, respectively); both received BLlike regimen. The patient with PR progressed after 7 months, and received a second line treatment likewise the 6 nonresponders to FLT. None of them had a response and eventually died, with a median OS of 10.5 months. Cause of death was lymphoma in all cases. The patient who obtained a CR was still in remission at 29 months from the end of the FLT. The survival of these pts, compared to pts with MYC rearrangement, is shown in Figure 1 (respectively 12% vs 57% at 2 years, p 0.04).Conclusion: These preliminary data show a dismal prognosis of pts with aggressive B cell lymphoma and MYC ICN, significantly worse than pts harboring a MYC translocation, independently of the treatment received. To better understand the genetic defect underlying this FISH pattern, further analysis using a specific centromere probe for chromosome 8 is ongoing on these and new cases. A previous study distinguished gain from amplification of MYC based on the number of gene copies, identifying 2 groups with different prognosis (Valera, Hematologica 2013). In our hands, there was a wider range of gene copy number in each patient, and the outcome was homogeneously poor. Overall, the biological consequence of this alteration is still to be fully explained, and only a few studies have addressed this point so far (Stasik, Hematologica 2010). Further investigation on larger cohort groups is necessary to confirm the unfavorable prognostic role of MYC ICN in aggressive B cell lymphoma. Such insights would help practitioners to determine more accurate therapeutic approaches, in order to improve the outcome of this specific subset of pts. [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Recurrent mutations in genes involved in nuclear factor-κB signalling in nodal marginal zone lymphoma-diagnostic and therapeutic implications.

To investigate the spectrum of mutations in 20 genes involved in B-cell receptor and/or Toll-like receptor signalling resulting in activation of nuclear factor-κB (NF-κB) in 20 nodal marginal zone lymphomas (NMZLs), 20 follicular lymphomas (FLs), and 11 cases of B-cell lymphoma, unclassifiable (BCL-u). Nodal marginal zone lymphomas were diagnosed according to strict criteria, including the expression of at least one putative marginal zone marker (MNDA and/or IRTA1). Cases that showed features of NMZL but did not fulfil all criteria were included as BCL-u. All FLs were required to have a BCL2 rearrangement. Mutations were found in: nine NMZLs, with recurrent mutations in TNFAIP3 and CD79B; 12 FLs, with recurrent mutations in TNFRSF14, TNFAIP3, and CARD11; and five cases of BCL-u, with recurrent mutations in TNFRSF14. TNFRSF14 mutations were present in FL and BCL-u, but not in any of the NMZLs. In the BCL-u group, TNFRSF14 mutations clustered with a FL immunophenotype. These results suggest that TNFRSF14 mutations point towards a diagnosis of FL, and can be used in the sometimes difficult distinction between NMZL and FL, but to apply this in diagnostics would require confirmation in an independent cohort. In addition, the presence or absence of specific mutations in pathways converging on NF-κB could be important for decisions regarding targeted treatment.