Classification Of Lymphoid Neoplasms Research Articles

New classifications of B-cell neoplasms: a comparison of 5th WHO and International Consensus classifications.

In 2024, the World Health Organization (WHO) launched a new classification of lymphoid neoplasms, a revision of the previously used Revised 4th Edition of their classification (WHO-4R). However, this means that two classifications are now in simultaneous use: the 5th Edition of the WHO classification (WHO-5) and the International Consensus Classification (ICC). Instead of a comprehensive review of each disease entity, as already described elsewhere, this review focuses on revisions made in both the WHO-5 and ICC from WHO-4R and discrepancies between them regarding B-cell neoplasms. Similarities include cutaneous marginal zone lymphoma, cold agglutinin disease, non-primary effusion lymphoma-type effusion-based lymphoma, and gray zone lymphoma. Differences include plasma cell neoplasms, high-grade B-cell lymphoma (double hit lymphoma), follicular lymphoma, LPD with immune deficiency and dysregulation, extranodal large B-cell lymphoma, transformations of indolent B-cell lymphomas, and diffuse large B-cell lymphoma, not otherwise specified. Understanding the similarities and differences between the two latest classifications will aid daily diagnostic practice and future research on lymphoid neoplasms.

Artificial intelligence and classification of mature lymphoid neoplasms.

Hematologists, geneticists, and clinicians came to a multidisciplinary agreement on the classification of lymphoid neoplasms that combines clinical features, histological characteristics, immunophenotype, and molecular pathology analyses. The current classification includes the World Health Organization (WHO) Classification of tumours of haematopoietic and lymphoid tissues revised 4th edition, the International Consensus Classification (ICC) of mature lymphoid neoplasms (report from the Clinical Advisory Committee 2022), and the 5th edition of the proposed WHO Classification of haematolymphoid tumours (lymphoid neoplasms, WHO-HAEM5). This article revises the recent advances in the classification of mature lymphoid neoplasms. Artificial intelligence (AI) has advanced rapidly recently, and its role in medicine is becoming more important as AI integrates computer science and datasets to make predictions or classifications based on complex input data. Summarizing previous research, it is described how several machine learning and neural networks can predict the prognosis of the patients, and classified mature B-cell neoplasms. In addition, new analysis predicted lymphoma subtypes using cell-of-origin markers that hematopathologists use in the clinical routine, including CD3, CD5, CD19, CD79A, MS4A1 (CD20), MME (CD10), BCL6, IRF4 (MUM-1), BCL2, SOX11, MNDA, and FCRL4 (IRTA1). In conclusion, although most categories are similar in both classifications, there are also conceptual differences and differences in the diagnostic criteria for some diseases. It is expected that AI will be incorporated into the lymphoma classification as another bioinformatics tool.

A Genomic Approach for High-Grade B Cell Lymphoma with MYC and BCL2 and / or BCL6 Rearrangements: Two Clusters Stood out on Next Generation Sequencing Results

Introduction High-grade B cell lymphomas with double or triple hit rearrangement (HGBL DH/TH), which appeared on the 4th revised edition WHO classification of lymphoid neoplasms, are aggressive mature B-cell lymphomas with high-grade cytology (Burkitt-like, blastoid or DLBCL-like) that have a MYC (8q24) rearrangement in combination with a BCL2 (18q21) and / or a BCL6 (3q27) rearrangement. There are currently no treatment guidelines for this subtype, and the usual immunochemotherapy leads to few complete remissions. While the NGS technology has been used in diffuse large B cell lymphoma, there has been no specific study on additional genetic events which would predict the clinical outcome in HGBL DH/TH. Here, we report our preliminary results using a targeted DNA capture panel approach (NGS) to identify subgroups with different clinical outcomes among HGBL DH/TH. Methods We conducted a retrospective study on 44 patients diagnosed with DH or TH HGBL and treated at Centre Hospitalier Lyon Sud or Centre Léon Bérard starting in 2013. We collected the medical information regarding the treatment, time to response to treatment or relapse, progression free survival, and overall survival. They all benefited from a DNA-targeted NGS analysis covering 54 genes. Results The cohort included 20 females and 24 males, with a median age of 65 (31-87). Among them, 22 patients were MYC/ BCL2 DH (50%), 12 were MYC/ BCL6 DH (27,3%) and 10 were TH (22,7%). Eleven patients had B symptoms (25%). The Ann Arbor stage was high (III-IV) in 97.5%. The WHO Performance Status was low (0-1) for most of the patients (70%). The majority of them presented with an IPI above to 2 (82,5%) and an elevated LDH level (80%). The Ki67 index was above 70% (33/42) in 78,5% of the cases and above 90% (19/42) in nearly half of them. The major finding of the NGS analysis was the identification of 2 groups based on the TP53/ CDKN2A_p14ARF mutational status. The CDKN2A locus encodes for 2 alternative open reading frames leading to 2 unrelated proteins p14ARF and p16INK4A. P14ARF is involved in the regulation of the TP53 pathway whereas p16INK4A is not. We therefor defined 2 groups : the first group included patients with either TP53 or CDKN2A_p14ARF-only alterations (group A, n=10) while the second group had no alteration in these two coding sequences (group B, n=34) although 12 patients had a CDKN2A_p16INK4A loss or mutation affecting both CDKN2A transcripts. Most of TP53 mutations were missense mutations mostly in TP53 DNA-binding domain and 2 cases appeared to be single hit mutations with an allele frequency below 50%. The patient with a p14ARF only mutation had a start codon mutation p.(M1*) with an allele frequency of 96% without CDKN2A copy number loss. The median overall survival (OS) (Figure 1) was 6,2 months for group A, and 55,5 months for group B (p = 0,0076). The median follow-up time was 14 months (7,5 months in the group A, 18 in group B). Only 2 patients in group A survived and are still in complete remission, one was DH BCL6 and the other DH BCL2 Conclusion Our preliminary results indicate a strong negative prognostic impact of either CDKN2A_p14ARF or TP53 gene alterations on the OS of HGBL DH/TH patients. The biological basis for the difference between groups would be in favour of the alteration of the p14ARF-TP53 tumor suppressive pathway as major contributor of chemoresistance. A more detailed analysis is on-going to further identify mutation profiles of double hit and triple hit lymphomas and compare our finding with existing data. Our results confirm the more favourable outcome of DH BCL6 patients (data not shown), which is consistent with the 5 th revised OMS classification that removed that specific entity. Our results also indicate that routine NGS analysis of HGBL DH/TH patients offers new perspectives for patient stratification. Regarding their survival, patients with TP53 pathway alterations should probably not be treated with the standard RCHOP chemo-immunotherapy. Instead, a more intensive immunochemotherapy regimen or novel strategies such as first-line bispecific antibodies or CARTCells might be considered.

A Multicenter, Open-Label, Phase 1b/2 Study to Evaluate the Effects of Maplirpacept in Combination with Tafasitamab and Lenalidomide in People with Relapsed or Refractory Diffuse Large B-Cell Lymphoma

Background Maplirpacept (PF-07901801) is an anti-CD47 molecule designed to enhance phagocytosis and antitumor activity by preventing CD47-mediated inhibitory signaling. Maplirpacept currently is being evaluated in an ongoing, multi-center, two-part, Phase 1a/1b study in participants with advanced hematologic malignancies (NCT03530683). Early safety and efficacy results for maplirpacept monotherapy have previously been reported in patients with refractory or relapsed lymphomas (Patel et al. Blood 2021;138:3560). Study Design This trial is a multicenter, open-label, Phase 1b/2 study (NCT05626322), to evaluate the effects of maplirpacept, in combination with tafasitamab and lenalidomide in participants with relapsed or refractory diffuse large B-cell lymphoma (DLBCL). The estimated enrollment is 70 patients, and the study will be split into two parts (Figure 1). Phase 1b will determine the maximum tolerated dose or recommended Phase 2 dose (2 dose levels) of maplirpacept, in combination with approved doses of tafasitamab and lenalidomide. In Phase 2, participants will be randomized to high or low doses of maplirpacept, in combination with approved doses of tafasitamab and lenalidomide, as per the Oncology Center of Excellence ‘Project Optimus’ initiative for dose optimization and selection in oncology drug development. Study interventions will be administered in 28-day cycles. Maplirpacept will be given weekly, by intravenous (IV) infusion, for the first three cycles and subsequently every two weeks. Tafasitamab will be administered, by IV infusion, on Days 1, 4, 8, 15 and 22 in cycle 1, weekly in cycles 2 and 3, then every 2 weeks in cycle 4 and beyond. Lenalidomide will be taken orally, daily for Days 1 to 21 of each 28-day cycle, for the first 12 cycles. In Phase 1b, approximately 20 participants will be allocated to sequential doses of maplirpacept, co-administered with approved doses of tafasitamab and lenalidomide, to select doses for further assessment in Phase 2. The primary endpoint for Phase 1b is to assess dose limiting toxicities up to 28 days following the first dose. In Phase 2, approximately 50 participants will be randomized to 1 of 2 different doses of maplirpacept, co-administered with tafasitamab and lenalidomide. The primary endpoint for Phase 2 is objective response as per the Lugano Response Classification Criteria 2014. Secondary endpoints are frequency of adverse events, frequency of clinical laboratory abnormalities, objective response (Phase 1b only), complete response, duration of response, duration of complete response, progression free survival, maplirpacept, tafasitamab and lenalidomide PKs, and immunogenicity of maplirpacept and tafasitamab. Inclusion criteria (Table 1) are adults with histologically confirmed, measurable relapsed and/or refractory DLBCL not otherwise specified, T cell/histiocyte rich large B-cell lymphoma, or Epstein-Barr virus positive DLBCL according to the 5th edition of the WHO classification of lymphoid neoplasms. Additionally, participants with follicular lymphoma grade 3b, or composite lymphoma with a DLBCL component with a subsequent DLBCL relapse are also eligible. Participants with evidence of histological transformation to DLBCL from an earlier diagnosis of low-grade lymphoma are eligible if relapsed or refractory to at least one line of therapy for DLBCL. Further inclusion criteria are participants who are not a candidates for, or are unwilling to receive, high-dose chemotherapy and subsequent stem cell transplant and/or are unable to undergo chimeric antigen receptor T-cell (CAR-T) therapy (e.g. due to logistical limitations), treatment with at ≥1 prior line of systemic therapy (for Phase 2, at least 1, and no more than 2, prior lines of systemic therapy) and prior therapy must include an anti-CD20 antibody. Participants must have adequate bone marrow, renal and hepatic function and an Eastern Cooperative Oncology Group performance status ≤2. Participants must provide a baseline tumor tissue sample (fresh or archival), for biomarker analysis. Exclusion criteria include previous treatment with anti-CD47, anti-CD19 (other than CAR-T) or immunomodulatory agents, prior allogeneic stem cell transplantation or autologous stem cell transplantation within 12 weeks prior to enrolment, and participants with active, uncontrolled viral, bacterial or fungal infections.

Integrated Genomic DNA/RNA Profiling vs Fluorescence in Situ Hybridization in the Detection of MYC and BCL2 (and BCL6) Rearrangements in Large B-Cell Lymphomas: Updates Amid the New WHO Classification of Lymphoid Neoplasms.

Large B-cell lymphomas (LBCLs) are a heterogeneous group of lymphoid neoplasms whose molecular and cytogenetic profile has predictive and prognostic implications. The concept of double-hit lymphomas (DHLs) was recently updated in the fifth edition of the World Health Organization classification, with the exclusion of MYC and BCL6 rearranged tumors from the group. Now, DHLs are referred to as diffuse large B-cell lymphoma/high-grade B-cell lymphoma with MYC and BCL2 rearrangements. Fluorescence in situ hybridization (FISH) is the current gold standard for detecting rearrangements in LBCLs, but comprehensive genomic profiling (CGP) has recently been suggested to be at least as accurate as FISH in classifying these neoplasms and providing additional genetic information. We analyzed a cohort of 131 patients in whom FISH and CGP studies were performed as part of our normal clinical workflow and compared the effectiveness of FISH and CGP in detecting these clinically relevant rearrangements. Our findings are in agreement with our previously published study, which analyzed a cohort of 69 patients, supporting our hypothesis that the best approach to maximize detection of DHLs while limiting waste seems to be a combination of CGP and MYC break-apart FISH testing, the latter to capture the presence of non-IGH::MYC events. Our study supports the combined use of FISH and GCP rather than either method alone to better detect MYC and BCL2 (and BCL6) gene rearrangements.

A Genomic Approach in High-Grade B Cell Lymphoma with MYC and BCL2 and / or BCL6 Rearrangements: Two Clusters Stood out on Next Generation Sequencing Results

Introduction Double or triple hit high-Grade B cell Lymphoma (HGBL), which appeared on the 4th revised edition WHO classification of lymphoid neoplasms in 2016, is a group of agressive mature B-cell lymphomas which morphogically ressemble diffuse large B-cell lymphoma (DLBCL) or with features intermediate between DLBCL and Burkitt lymphoma, that have a MYC (8q24) rearrangement in combination with a BCL2 (18q21) and / or a BCL6 (3q27) rearrangement. There are currently no treatment guidelines for DH/TH HGBL, and the usual chemotherapy leads to few complete remissions. While the whole exome sequencing technology has been used in diffuse large B cell lymphoma, there has been few studies on additional DH/TH HGBL genetic events which would predict the clinical outcome. Here, we report our preliminary results on DH/TH HGBL patients using a targeted DNA capture panel approach (NGS) to identify subgroups with different clinical outcomes among DH/TH HGBL. Methods We conducted a retrospective study on 66 patients diagnosed with DH or TH HGBL and treated at Centre Hospitalier Lyon Sud or Centre Léon Bérard starting in 2013. We collected the medical information regarding the treatment, time to response to treatment or relapse, progression free survival, and overall survival. In addition, we performed a preliminary NGS analysis on the most recent samples using SophiaGenetics LYS panel (54 genes) in Centre Léon Bérard. Results The cohort included 30 females and 36 males, with a median age of 65 (IQR: 56.25-72.75). Among them, 32 patients were MYC/BCL2 DH (48.49%), 14 were MYC/BCL6 DH (21.21%) and 20 were TH (30.30%). Nine patients had B symptoms (9/62 14.52%). The Ann Arbor stage was high (III-IV) (59/66, 89.39%). The WHO Performance Status was low (0-1-2) for most of the patients (52/59, 88.14%). The majority of them presented with an IPI above to 2 (39/51, 76.47%) and an elevated LDH level (48/62, 77.42). The Ki67 positivity was above 70% (52/62, 83.87%) in most of the patients and above 90% (27/62, 43.55%) in nearly half of them. The median follow-up time was 11 months (IQR: 6-37.75) for the cohort. The major finding of the NGS analysis was the identification of 2 clusters based on the TP53/CDKN2A mutational status. The first group included patients with mutually exclusive TP53 or CDKN2A alterations (cluster A, n=7) while the second group had no alteration in these two genes (cluster B, n=7). TP53 alteration consisted exclusively in gene mutations while we found loss of heterozygoty or point mutation for CDKN2A. The median progression free survival (PFS) (Figure 1) and overall survival (OS) (Figure 2) were 5.39 months (IQR: 6.51-NA) and 6.18 month (IQR: 5.88-NA) for group A respectively, and were not achieved for cluster B. The median follow-up was 5.88 months (IQR: 4.24-7.69) for cluster A and 11.56 months (IQR: 9.3-31.6) for cluster B, the difference being due to the higher mortality rate in cluster A. Conclusion Our preliminary results indicate a strong negative prognostic impact of either CDKN2A or TP53 gene alterations on the PFS and OS in HGBL DH/TH patients. Although the difference was not statistically significant between clusters with only 14 patients having NGS results, we plan to include other samples to further consolidate the data. More importantly, the biological basis for the difference between clusters would be in favour of the alteration of the ARF-TP53 tumor suppressive pathway as major contributor to survival since one of our sample had only a point mutation in ARF start codon. Taken together, our results suggest that routine NGS analysis of HGBL DH/TH patients may offer new perspectives on patient stratification and possibly new classification and therapeutic opportunities such as MDM2 or BCL2 inhibitors, in combination with conventional chemotherapy and need to be confirmed in a larger population. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Primary Cutaneous Peripheral T-Cell Lymphoma, Not Otherwise Specified: Characterization of a Large Cohort with Long-Term Outcomes Shows Disparate Outcomes By Body Region Involvement

INTRODUCTION: Primary cutaneous peripheral T-cell lymphoma, not otherwise specified (pcPTCL-NOS) is defined as PTCL-NOS presenting only in the skin with no evidence of extracutaneous disease; this is a poorly-characterized diagnosis only recently recognized as a distinct entity by the World Health Organization-European Organization for Research and Treatment of Cancer (WHO-EORTC) classification system and the 5th edition of the WHO Classification of Lymphoid Neoplasms (Willemze et al., Blood 2019; Alaggio et al., Leukemia 2022). Few series exist and most include other histologies or patients with concomitant systemic disease. We aimed to characterize the clinical presentation and treatment of a large cohort of patients with pcPTCL-NOS. METHODS: Through the Memorial Sloan Kettering Cancer Center (MSKCC) patient database, patients with a diagnosis of T-cell lymphoma and at least one visit at MSKCC between January 1, 2001 and December 31, 2021 were identified. Only patients with pathologically-confirmed PTCL-NOS confined to the skin at diagnosis were included. Patients with any WHO-recognized diagnosis other than PTCL-NOS were excluded, as were patients with concomitant systemic disease at diagnosis. All cases underwent pathology review at MSKCC. Patients were classified by the number of lesions and number of involved body regions at diagnosis (single lesion, regional [>1 lesion but only 1 body region], and multiple body regions). Management strategies were classified as systemic therapy, focal radiotherapy (RT), surgical excision, observation, combined modality therapy, or other approaches. Responses were assessed by reviewing clinical documentation. Progression-free (PFS) and overall survival (OS) probabilities were estimated by the Kaplan-Meier method and compared for various features using the log-rank test. PFS was measured from the date of initial treatment, and OS was measured from the time of initial diagnosis. For multiple variables of interest, a univariate analysis was performed to estimate associations with survival. RESULTS: Forty patients with pathologically-confirmed pcPTCL-NOS were identified (Table 1). Site of involvement varied, as did disease extent at presentation (solitary lesion: 21/40; regional: 6/40; multiple body regions: 13/40). Classic B symptoms (1/40), ulceration (7/40), and tumor lesions (12/40) were uncommon. Initial treatment strategies varied by disease extent. For those with only a single lesion or regional disease, excision, focal RT, or excision followed by focal RT were the most common upfront strategies (21/27). Four patients with single/regional disease were observed. For those receiving upfront focal RT with or without excision, objective responses were achieved in 17 patients (ORR: 85%; CR: 80%). Among those who relapsed after upfront focal RT with or without excision (n=11/20), all relapses occurred outside the RT field. In patients with involvement of multiple body regions, systemic therapy with or without RT (6/13) was the most common approach. Median PFS and OS of the entire cohort was 18.1 (95% CI 0.3-35.9) and 125.1 (18.7-231.8) months, respectively. However, by disease extent, median OS for those with a solitary lesion, regional disease, and involvement of multiple regions was 125.9, 125.2, and 33.6 months, respectively (p=0.01) (Figure 1). When analyzed by body region alone, patients with involvement of one versus greater than one body region at diagnosis had median OS of 125.0 versus 33.6 months, respectively (p=0.002). The presence of greater than one lesion (HR 7.6, 95% CI 2.5-22.9), disease across multiple body regions (HR 3.4, 95% CI 1.3-9.0), and tumor lesions (HR 10.1, 95% CI 3.3-31.3) conferred increased risk of progression. Similarly, disease across multiple body regions (HR 4.1, 95% CI 1.1-14.7) and tumor lesions (HR 9.5, 95% CI 3.0-31.0) conferred increased risk of death. CONCLUSIONS: To our knowledge, this is the largest series of pcPTCL-NOS and importantly excludes all other WHO-recognized T-cell lymphoma diagnoses and those with systemic disease. Patients with a single lesion or regional disease had significantly greater survival than those with multiple regions involved despite relatively frequent relapses and differences in therapeutic strategy/intensity. Patients with multiple body regions involved underwent varied treatment strategies and experienced poor outcomes. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Routine application of the Lymph2Cx assay for the subclassification of aggressive B-cell lymphoma: report of a prospective real-world series.

The subclassification of diffuse large B-cell lymphoma (DLBCL) into germinal center B-cell-like (GCB) and activated B-cell-like (ABC) subtypes has become mandatory in the 2017 update of the WHO classification of lymphoid neoplasms and will continue to be used in the WHO 5th edition. The RNA-based Lymph2Cx assay has been validated as a reliable surrogate of high-throughput gene expression profiling assays for distinguishing between GCB and ABC DLBCL and provides reliable results from formalin-fixed, paraffin-embedded (FFPE) material. This test has been previously used in clinical trials, but experience from real-world routine application is rare. We routinely applied the Lymph2Cx assay to day-to-day diagnostics on a series of 147 aggressive B-cell lymphoma cases and correlated our results with the immunohistochemical subclassification using the Hans algorithm and fluorescence in situ hybridization findings using break-apart probes for MYC, BCL2, and BCL6. The routine use of the Lymph2Cx assay had a high technical success rate (94.6%) with a low rate of failure due to poor material and/or RNA quality. The Lymph2Cx assay was discordant with the Hans algorithm in 18% (23 of 128 cases). Discordant cases were mainly classified as GCB by the Hans algorithm and as ABC by Lymph2Cx (n = 11, 8.6%). Only 5 cases (3.9%) were classified as non-GCB by the Hans algorithm and as GCB by Lymph2Cx. Additionally, 5.5% of cases (n = 7) were left unclassified by Lymph2Cx, whereas they were defined as GCB (n = 4) or non-GCB (n = 3) by the Hans algorithm. Our data support the routine applicability of the Lymph2Cx assay.

Classifying Germinal Center Derived Lymphomas—Navigate a Complex Transcriptional Landscape

Simple SummaryGerminal center-derived B-cell lymphomas constitute a very heterogeneous group of neoplasms with diverse clinical presentations, prognoses, and responses to therapy. They divide into a series of subtypes, such as Diffuse Large B-cell lymphomas (DLBCL), Burkitt Lymphomas (BL), Follicular lymphomas (FL), and further, into several subclasses and rarer subtypes of finer granularity, which makes them one of the most heterogeneous cancer entities. Molecular classification schemes, first of all, derived from whole transcriptome gene expression data largely improved subtyping and functional understanding. Based on a whole transcriptome landscape of B-cell lymphoma, we show that one major caveat in the task of classification is represented by the rather fuzzy distribution of individual tumors without clear-cut borderlines between most of the subtypes, preventing their unambiguous association with clear-cut entities. This landscape is governed by the germinal center (GC) reaction and relates different subtypes to different states along the reaction path. We discuss the relatedness between the expression landscape and classifier signatures and their functional cell of origin background. This view helps to stratify lymphomas in terms of modular building blocks of signature genes and to interpret rarer subclasses in the context of larger ones.Classification of lymphoid neoplasms is based mainly on histologic, immunologic, and (rarer) genetic features. It has been supplemented by gene expression profiling (GEP) in the last decade. Despite the considerable success, particularly in associating lymphoma subtypes with specific transcriptional programs and classifier signatures of up- or downregulated genes, competing molecular classifiers were often proposed in the literature by different groups for the same classification tasks to distinguish, e.g., BL versus DLBCL or different DLBCL subtypes. Moreover, rarer sub-entities such as MYC and BCL2 “double hit lymphomas” (DHL), IRF4-rearranged large cell lymphoma (IRF4-LCL), and Burkitt-like lymphomas with 11q aberration pattern (mnBLL-11q) attracted interest while their relatedness regarding the major classes is still unclear in many respects. We explored the transcriptional landscape of 873 lymphomas referring to a wide spectrum of subtypes by applying self-organizing maps (SOM) machine learning. The landscape reveals a continuum of transcriptional states activated in the different subtypes without clear-cut borderlines between them and preventing their unambiguous classification. These states show striking parallels with single cell gene expression of the active germinal center (GC), which is characterized by the cyclic progression of B-cells. The expression patterns along the GC trajectory are discriminative for distinguishing different lymphoma subtypes. We show that the rare subtypes take intermediate positions between BL, DLBCL, and FL as considered by the 5th edition of the WHO classification of haemato-lymphoid tumors in 2022. Classifier gene signatures extracted from these states as modules of coregulated genes are competitive with literature classifiers. They provide functional-defined classifiers with the option of consenting redundant classifiers from the literature. We discuss alternative classification schemes of different granularity and functional impact as possible avenues toward personalization and improved diagnostics of GC-derived lymphomas.

EBV-positive diffuse large B-cell lymphoma, not otherwise specified: 2022 update on diagnosis, risk-stratification, and management.

Epstein Barr virus-positive (EBV+) diffuse large B-cell lymphoma (DLBCL), not otherwise specified (NOS) is an entity included in the WHO classification of lymphoid neoplasms since 2016. EBV+ DLBCL, NOS, is an aggressive B-cell lymphoma associated with EBV infection, and a poor prognosis with standard chemotherapeutic approaches. The diagnosis is made through a careful pathological evaluation. Detection of EBV-encoded RNA (EBER) is considered standard for diagnosis; however, a clear cutoff for percentage of positive cells has not been defined. The differential diagnosis includes plasmablastic lymphoma (PBL), DLBCL associated with chronic inflammation, primary effusion lymphoma (PEL), among others. The International Prognostic Index (IPI) and the Oyama score can be used for risk-stratification. The Oyama score includes age >70 years and presence of B symptoms. The expression of CD30 and PD-1/PD-L1 are emerging as potential adverse but targetable biomarkers. Patients with EBV+ DLBCL, NOS, should be staged and managed following similar guidelines than patients with EBV-negative DLBCL. EBV+ DLBCL, NOS, however, might have a worse prognosis than EBV-negative DLBCL in the era of chemoimmunotherapy. Therefore, the inclusion of patients in clinical trials when available is recommended. There is an opportunity to study and develop targeted therapy in the management of patients with EBV+ DLBCL, NOS.

An Overview of Selected Rare B-Cell Lymphoproliferative Disorders: Imaging, Histopathologic, and Clinical Features.

Simple SummaryThe updated 4th edition WHO classification of lymphoid malignancies released in 2016 contains pivotal new terminology and information that is important for radiologists to understand. In spite of these updates, some lymphoproliferative disorders included in this update have been rarely discussed in the radiology literature. Many of these disorders have distinct clinical and imaging features, overlapping with more common disorders, thus causing a delay in diagnosis and management. Early diagnosis of many of these disorders is key as many of these are potentially treatable because early intervention may be lifesaving. The purpose of this manuscript is to provide guidance for radiologists regarding certain rare variants of B-cell lymphoproliferative disorders, in terms of clinical, histologic, and imaging findings, as well as to incorporate the new and updated terminology of some disorders included within the 4th edition of the WHO classification of lymphoid neoplasm.Lymphoproliferative disorders (LPD) are conditions characterized by the uncontrolled proliferation of B or T-cell lines. They encompass a wide spectrum of abnormalities, which may be broadly classified as reactive processes or malignant diseases, such as lymphoma, based on their cellular clonality and clinical behavior. While some of these disorders are rare, they may be encountered sporadically in clinical practice, causing diagnostic dilemmas owing to overlap in their clinical and imaging features with more common disorders. The updated 4th edition WHO classification of lymphoid neoplasms was released in 2016 to incorporate the rapid clinical, pathological, molecular biology and cytogenetic advances of some of these disorders. Despite these updates, very little information is presented in the literature from the radiology perspective. The aim of this article is to familiarize radiologists and other physicians with certain rare variants of B-cell lymphoproliferative disorders with a focus on imaging features of these disorders, as well as to provide an overview of some important updates contained within the new WHO classification of lymphoid neoplasms.

Impact of Timing and Precision of Histopathological Diagnosis on Outcomes of Patients with Burkitt and High-Grade B-Cell Lymphoma

Background:The genetic hallmark of BL is MYC gene rearrangement. However, due to histopathological, immunohistochemical and cytogenetic similarities, differentiation from Diffuse Large B-Cell Lymphoma (DLBCL) remains challenging in some cases. Although being suspected to negatively influence outcomes, detection of high expression of BCL2 and MYC (double expressor) as well as rearrangements of MYC and BCL2 and/or BCL6 (double/triple hit) did not lead to confirmation of different therapeutic approaches in DLBCL yet. The recent update of the World Health Organization (WHO) classification of lymphoid neoplasms has thus established a category termed High-Grade B-Cell Lymphoma (HGBL), defined by a distinct morphology and/or presence of double/triple hit status. While BL displays favorable outcomes in clinical routine upon treatment with intensive immunochemotherapeutic regimens, clear evidence regarding the optimal therapeutic approach for HGBL remains limited and the diagnostic discrimination of BL and HGBL can be challenging, too. Moreover, data on the frequency of revisions of the diagnosis of BL to DLBCL or HGBL and its impact on treatment and outcome are sparse.Methods:All consecutive patients managed with histopathological suspected diagnosis of BL upon preliminary assessment at the reporting institution between December 2010 and July 2020 were identified. Final diagnosis of the respective aggressive B-Cell lymphoma was grouped according to the most recent WHO classification and divided into four subgroups: a) BL, b) revision from DLBCL to BL, c) DLBCL, d) HGBL. General patient characteristics as well as response to treatment in Computed Tomography (CT) or Positron Emission Tomography (PET) (evaluation by individual investigator), information regarding survival supported by the register of deaths in North-Rhine Westphalia and the date of last follow-up were collected from individual patient files.Results:Overall, we identified n=66 patients with suspected diagnosis of BL within the preliminary assessment. Final histopathological results confirmed n=31 patients as BL (Group A), while n=23 patients were described as showing features of both BL and DLBCL (Uncertain & Grey-zone, Group D). Additionally, in n=12 patients the final diagnosis was revised either from DLBCL to BL (n=9, Group B) or B-ALL/BL to DLBCL (n=3, Group C). Regarding the reference histopathological reviews (RHR) and the latest version of the WHO classification of lymphoid neoplasms, all patients from Group C and Group D were finally classified as either DLBCL (n=12) or HGBL (n=14). In total, n=13 patients had revision of the final diagnosis, either upon receipt of RHR (n=8) or repeated biopsy upon progressive disease (PD) (n=5). When comparing patients with revised diagnosis due to PD or RHR, a median of six (range 4-8) and two (range 1-2) cycles of systemic therapy were applied prior to revision, respectively. Regarding outcomes, 2/5 patients (40%) with revised diagnosis upon PD and 7/8 patients (87,5%) with revised diagnosis upon RHR were alive at the time of last follow-up (median follow-up 15,07 months), respectively (Fig 1). Patients suffering from BL (Group A) displayed a significantly increased progression-free survival (PFS) compared to all other groups (p=0.034). In contrast, patients whose diagnosis was revised from DLBCL to BL after initiation of treatment with DLBCL protocols had an inferior PFS than patients initially diagnosed with BL (p=0.045) that was comparable to patients with the final diagnosis of DLBCL or HGBL. Two-year overall survival was generally favorable in all groups, ranging from almost 60% (HGBL) to 86,2% (BL) without showing statistically significant differences (p=0.2).ConclusionIn conclusion, timely and precise histopathological diagnostic procedures seem to play a critical role for optimizing treatment strategies of BL, HGBL and high-risk DLBCL upfront. Since administration of BL treatment protocols seems feasible in clinical routine and may result in favorable results not only in BL but as well in HGBL, these results might encourage its upfront usage in doubtful situations regarding histopathological results. However, with only a small number of patients being evaluable in the present analysis, controlled clinical trials are necessary to confirm these trends. [Display omitted] DisclosuresHeger: Novartis: Research Funding; Gilead: Other: Travel funding. Gödel: Gilead: Other: Personal fees / travel support; Novartis: Other: Travel support. Balke-Want: Novartis: Research Funding. Simon: Gilead: Other: Travel support. Bröckelmann: BMS: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; MSD: Research Funding; BeiGene: Research Funding. Von Tresckow: Amgen: Consultancy, Honoraria; AstraZeneca: Honoraria, Other: Congress and travel support; AbbVie: Other: Congress and travel support; BMS-Celgene: Consultancy, Honoraria, Other: Congress and travel support; Kite-Gilead: Consultancy, Honoraria; MSD: Consultancy, Honoraria, Other: Congress and travel support, Research Funding; Novartis: Consultancy, Honoraria, Other: Congress and travel support, Research Funding; Pentixafarm: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; Roche: Consultancy, Honoraria; Takeda: Consultancy, Honoraria, Other, Research Funding.

Uncommon Variants of Mature T-Cell Lymphomas (MTCLs): Imaging and Histopathologic and Clinical Features with Updates from the Fourth Edition of the World Health Organization (WHO) Classification of Lymphoid Neoplasms.

Simple SummaryFamiliarity with the updated fourth edition WHO classification of lymphoid malignancies released in 2016, and the new terminology introduced, is crucial for oncologists, pathologists and radiologists. It is mandatory to be aware of rare variants of T-cell lymphomas, specifically mature T-cell lymphomas, including clinicopathologic keys and the most common imaging features and sites of involvement for each subtype. Even though some of these disorders may have perceptible clinical and imaging features, they may overlap with more common disorders, causing delay in diagnosis and treatment. Understanding the appropriate clinical setting and imaging findings will help radiologists to include these disorders in their differential diagnosis. Imaging plays a pivotal role in subclassifying these subtypes of MTCLs, affecting prognosis and treatment implications. Many of these disorders if diagnosed early can be potentially treatable, and early, aggressive intervention may be lifesaving.Understanding the pathogenesis and molecular biology of malignant lymphomas is challenging, given the complex nature and incongruity of these disorders. The classification of lymphoma is continually evolving to account for advances in clinical, pathological, molecular biology and cytogenetic aspects, which impact our understanding of these disorders. The latest fourth edition of the WHO classification of lymphoid malignancies was released in 2016 to account for these changes. Additionally, unlike B-cell lymphomas (BCL), T-cell lymphomas (TCL) are uncommon, and may be sporadically experienced in clinical practice. These disorders are rare, thus early diagnosis is challenging for both physicians and radiologists, owing to the overlap in clinical and imaging features with other, more common disorders. We aim to discuss some rare variants of T-cell lymphomas, including clinicopathologic and imaging features, as well as to give a glimpse of the updates contained within the new 2016 WHO classification.

Malignant Lymphoma Involving Peripheral Nervous System and Skeletal Muscle

The 2016 revision of the WHO classification of lymphoid neoplasms has been published. Although pathological analysis is necessary for the diagnosis of malignant lymphoma, genetic analysis has become increasingly important in recent years. The diagnosis of malignant lymphoma in the peripheral nerves and skeletal muscles is challenging; hence, diagnosis based on genetic profiles is desirable. In this article, previous studies on malignant lymphoma in the peripheral nerves and skeletal muscles are summarized. Common clinical findings, radiological characteristics, and genetic tests were reviewed.

BCL2 translocation in high grade B cell lymphoma (NOS, DH/TH) is associated with reduced progression free survival

High Grade B Cell Lymphoma, NOS, and High Grade B Cell Lymphoma with Dual Hit or Triple Hit have been recently recategorized in the 2016 revision of the WHO classification of lymphoid neoplasms. In this study we have characterized the genetic, histopathological, and clinical features of a series of this type of lymphoid neoplasia (17 HGBCL NOS and 53 HGBCL DH/TH). HGBCL NOS showed better response to first line treatment than HGBCL with DH/TH but no significant differences in PFS or OS were found between the two categories. Survival analysis in the whole cohort of cases found that only the presence of BCL2 translocation was significantly associated with PFS. Other clinical features such as IPI, LDH or stage were equivalent in both categories. Furthermore, both high grade and DLBCL morphological patterns showed equivalent PFS and OS in this set of High grade BCL NOS/DH/TH. Key points BCL2 translocation in High Grade B Cell Lymphoma NOS and High Grade B Cell Lymphoma with DH/TH is associated with reduced progression free survival. Both high grade and DLBCL morphological patterns showed equivalent outcome regarding PFS and OS in HGBCL.

CLL-156: Novel CCL22 Mutations Drive Chronic Lymphoproliferative Disorder of NK Cells Through Biased GPCR Signaling

Context: Chronic lymphoproliferative disorder of natural killer cells (CLPD-NK) is a subset of large granular lymphocyte (LGL) leukemia included as a provisional entity in the 2016 WHO classification of lymphoid neoplasms, which is characterized by clonal expansion of NK cells with no standardized therapy. STAT3 and TET2 mutations were previously each reported in 15%–30% of cases; however, the genomic basis of the remaining cases is still unknown. Objective: We aimed to perform a comprehensive genomic and transcriptomic analysis of CLPD-NK to elucidate the genomic landscape, investigate mechanisms of pathogenesis, and improve diagnostic classification and treatment strategies. Methods: CLPD-NK samples (n=121) were examined by whole-genome, targeted, and/or whole-transcriptome sequencing. Structural modeling, G-protein signaling, β-arrestin signaling, G-protein-coupled receptor (GPCR) for CCL22, CCR4 internalization, and chemotaxis were examined. Cell line-derived xenografts were used to examine cell proliferation and phenotype. Results: Somatic mutations in the chemokine CCL22 were found in 21.5% of CLPD-NK patients but not in 2837 cases of other hematological malignancies, including T-LGL and other NK leukemias. Clinically, there was a trend to an association with cutaneous complications and/or neurological symptoms. CCL22 mutations were enriched at the highly conserved residues Leu45, Pro46, and Pro79 and were mutually exclusive of STAT3 mutations. CCL22 mutations were associated with dysregulated gene expression, similar to normal CD56bright NK cells, with enrichment for activation of cytokine signaling pathways, representing a distinct subgroup. Most CCL22 mutations were substitutions to Arg, a basic residue, and Leu45Arg was predicted to promote electrostatic interactions with CCR4-Tyr22/Glu23 acidic residues. The mutations resulted in ligand-biased CCR4 signaling, in which activation of G-protein signaling was unchanged, but recruitment of β-arrestin, which mediates receptor internalization, was impaired, which, in turn, resulted in enhanced cell chemotaxis. CCL22 mutations drove enhanced cell proliferation in vivo in hIL-15-transgenic mice and induced an expression profile resembling that of primary samples, indicating the importance of microenvironmental crosstalk in pathogenesis. Conclusions: Somatic CCL22 mutations defined a new subgroup of CLPD-NK similar to CD56bright normal NK cells and represented a novel mechanism of leukemogenesis in which gain-of-function chemokine mutations drive tumorigenesis by biased GPCR signaling and dysregulation of microenvironmental crosstalk.

Distinct pattern of lymphoid neoplasms characterizations according to the WHO classification (2016) and prevalence of associated Epstein\u2013Barr virus infection in Nigeria population

BackgroundThe present study aimed to classify lymphoid neoplasms according to the latest World Health Organization (WHO) classification and outlining the distribution in Nigeria of different entities. Additionally, the study describes the prevalence of lymphoid neoplasms associated with Epstein-Barr virus (EBV) infection in the Nigerian population.MethodsWe collected 152 formalin-fixed paraffin-embedded (FFPE) tissues diagnosed as lymphoma from 2008 to 2018, coming from three different institutions located within three geopolitical zone in Nigeria. These institutions included the University College Hospital (UCH), Ibadan, Oyo State, the Enugu State University of Science and Technology Teaching Hospital (ESUTH), Enugu, Enugu State, and the Meena Histopathology and Cytology Laboratory (MHCL), Jos, Plateau State.ResultsFrom the total 152 cases retrieved, 50 were excluded due to insufficient tissue materials or inconclusive antigen reactivity. We confirmed 66 (64.7%) cases as lymphomas out of the remaining 102 FFPE with a male to female ratio of 2:1 and a mean age of 44.4 years. Ten entities were identified, and of these, chronic lymphocytic leukemia (CLL) was the most prevalent category (34.8%). For the diffuse large B-cell lymphomas not otherwise specified (DLBCL, NOS), the germinal centre B–cell type was the most common (71.4%). Ten lymphoma cases (15.2%) were positive for Epstein-Barr virus (EBV), most of which were Hodgkin lymphoma (HL). CLL was common in the Hausa ethnic group, HL in the Yoruba ethnic group, while the Igbo ethnic group had an equal distribution of CLL, HL, and DLBCL diagnosis.ConclusionAlthough the distribution of lymphomas in Nigeria shares some similarities with those of other countries, we described distinct features of some subtypes of lymphomas. Also, the study underscores the need for a more precise diagnosis and classification of lymphoid neoplasms in Nigeria using the latest WHO classification.

MYD88 L265P mutation in primary central nervous system lymphoma is associated with better survival: A single-center experience.

BackgroundThe myeloid differentiation primary response gene (MYD88) mutation in primary central nervous system lymphomas (PCNSL) may be associated with unfavorable prognosis; however, current evidence remains limited. We aimed to characterize PCNSLs by integration of clinicopathological, molecular, treatment, and survival data.MethodsWe retrospectively identified and validated 57 consecutive patients with PCNSLs according to the 2017 WHO classification of lymphoid neoplasms over 13 years. Formalin-fixed paraffin-embedded tumor samples underwent polymerase chain reaction assay to detect MYD88 mutation. We used Cox regression for survival analysis, including age, treatment, and MYD88 as covariates. We searched the literature for studies reporting demographics, treatment, MYD88, and survival of PCNSL patients and incorporated individual patient data into our analyses.ResultsThe median age was 66 years and 56% were women. All 57 patients had PCNSL of non-germinal center cell subtype and the majority (81%) received either single or combined therapies. There were 46 deaths observed over the median follow-up of 10 months. MYD88 mutation status was available in 41 patients of which 36 (88%) were mutated. There was an association between MYD88 mutation and better survival in the multivariable model (hazard ratio [HR] 0.277; 95% confidence interval [CI]: 0.09-0.83; P = .023) but not in a univariable model. After incorporating additional 18 patients from the literature, this association was reproducible (HR 0.245; 95% CI: 0.09-0.64; P = .004).ConclusionsAdjusting for confounders, MYD88-mutant PCNSL appears to show improved survival. While further validation is warranted, detection of MYD88 mutation will aid the identification of patients who may benefit from novel targeted therapies.

Clinicopathology, Disease Progression/Transformation and Genomic Alterations of Indolent T-Cell Lymphoproliferative Disorder of the Gastrointestinal Tract

Introduction: Indolent T-cell lymphoproliferative disorder of the gastrointestinal tract (ITCLD-GT) is a newly recognized entity in the 2016 revision of the World Health Organization (WHO) classification of lymphoid neoplasms. ITCLD-GT is defined as a clonal T-cell proliferation occurring in the GT, mostly in colon and small bowel. So far only 52 ITCLD-GT cases have been reported. It has a pathologically nondestructive expansionary growth pattern, a less than 10% Ki67 proliferative index and an indolent clinical course. However, the pathological characteristics of ITCLD-GT in lesions except the small and large intestines, its clinical progress/transformation and pathogenetic mechanisms and molecular alterations remain unknown. Methods: Nine ITCLD-GT cases were collected from one center in southwest China, and their clinicopathological were analyzed. Of these patients, 7 had indolent clinical courses; one had lymph node metastasis in the late stage; and another one transformed into diffuse large B-cell lymphoma (DLBCL) after 16 months (Figure A). In one patient, neoplastic cells involved most of the digestive tract from esophagus to rectum. Whole-exome sequencing was performed in 9 samples from 7 cases. Genome-wide mutation landscape was analysed on these ITCLD-GT samples and pairwise comparison was made between stomach and colon lesions as well as between ITCLD-GT and transformed DLBCL samples. Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed. Results: The median age of the patients was 47 years, and the male/female ratio was 7:2. Clinically, these patients presented with diarrhea with or without abdominal pain, abdominal distension, fatigue or hematochezia. Colonoscopy showed thickened intestinal mucosa in 8 cases, with small nodularity and folds in 7 cases and polyps resembling in 1 case. Intestinal mucosa surfaces showed patchy erythema, erosion or superficial ulcer with diameter ≥ 2.5cm. Endoscopy showed thickened gastric mucosa, nodular protrusion or multiple wide pedicle polyps. Microscopically, the lamina propria was displaced by the infiltrate of dense, monotonous and small lymphocytes, but the mucosal glands were not destroyed. All the infiltrated lymphocytes were positive for CD3p and TIA-1, mostly positive for CD2, CD5 and CD7 and negative for CD20 and Granzyme B. 8 cases were positive for CD8 and 1 case expressed CD4. In the case with esophagus and GT involvement, CD56 was positive in gastric and intestinal lesions, but negative in esophageal and colon. The proliferative index of Ki67 was less than 10% in all cases at diagnosis, but in one case it increased to 20% after 4 years (Figure B). In all cases, monoclonal TCR gene rearrangement was positive and EBER1/2 was negative. The landscape of gene alterations using WES in these patients were analysed (Figure C). The recurrent mutated genes included cancer-related gene PDE4DIP, transcription regulatory genes BAZ2B and CNOT6L, signaling transduction-related genes MUC17 and PIEZO2, metabolism regulatory genes PLA2G4D and FRG2C, cytoskeleton and cell adhesion-associated genes COL14A1, DNAH5 and many other genes were shown in Figure C. GO analysis showed that mutated genes were significantly enriched in microtubule cytoskeleton organization. KEGG pathway analysis indicated that the mutated genes were mostly enriched in focal adhesion and ECM-receptor interaction, both associated with cancer development. Pairwise comparison analysis of lesions from the stomach and colon showed that there was almost no genetic difference between the two lesions. JAK3, NRAS and SETD2 mutations and BCOR deletion may contribute to the entire digestive tract distribution of ITCLD-GT. The transformed aggressive DLBCL sample carried 253 more mutated genes than the indolent ITCLD-GT sample. Mutations of TP53, ARID1A, KMT2D and M2P2K1 only in the DLBCL sample may contribute to the transformation of ITCLD-GT to DLBCL. Conclusion: Our study summarized the clinicopathological characterization of 9 cases of ITCLD-GT. ITCLD-GT is generally inert, but it may develop with an increased Ki67 proliferation index in the late stage or even turn into aggressive DLBCL. We characterized the genomic alterations in ITCLD-GT and revealed its molecular pathogenesis and progression, which might be helpful for diagnosis, prognosis and treatment of this rare lymphoid neoplasm. Figure 1 Disclosures No relevant conflicts of interest to declare.

Indolent T-Cell Lymphoproliferative Disease of the GI Tract: Insights for Better Diagnosis, Prognosis, and Appropriate Therapy.

Indolent T-cell lymphoproliferative disease of the gastrointestinal tract (indolent GI T-LPD) is a benign neoplasm of CD4+ or CD8+ T cells that form primary tumors in the GI tract. Indolent GI T-LPD has recently been provisionally recognized as a distinct entity by the 2016 revision of the WHO classification of lymphoid neoplasms. Appropriate diagnosis of these cases is challenging as they may be misdiagnosed as T cell lymphoma that has an aggressive clinical course. Consequently, aggressive therapeutic approaches were usually chosen to treat these cases with no obvious benefit for most of the patients and potential side effects. Moreover, inflammatory diseases of the GI tract with similar symptoms may lead to misdiagnosis that leads to delays in administration of proper therapeutics against these cases. Therefore, it is of utmost importance to identify prognostic genetic biomarkers at the time of diagnosis for optimal medical care of these patients. TCR clonality analyses may not be useful for distinguishing these benign neoplasms from aggressive gastrointestinal T cell lymphomas; however, molecular genetic tests may prove useful as recurrent STAT3-JAK2 fusions, which may have diagnostic, prognostic or therapeutic value, have recently been identified. However, there is still lack of comprehensive information on the genetic and epigenetic factors associated with pathogenesis of indolent GI T-LPD. In this mini-review, we focus on the so far reported literature on indolent GI T-LPD cases, and discuss future directions for better differential diagnosis, risk stratification, and therapeutic target discovery with a special focus on the genetic and epigenetic alterations.