WHO Classification Of Lymphoid Neoplasms Research Articles

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.

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.

Next-Generation Sequencing Reveals Molecular Heterogeneity in Primary Testicular DLBCL

Background:Primary testicular lymphomas (PTLs) are extra-nodal large B-cell lymphomas (LBCLs) that respond poorly to current empirical treatment options. To date, no PTL whole-exome sequencing analysis based on the Chinese population has been reported. The main objective of this study was to explore the genomic landscape of PTDLBCL, correlating the results with clinical, histological, and immunogenetic features.Methods:We retrospectively analyzed the disease characteristics in a series of 20 patients (13 paired data and 7 unpaired data). In all cases, the diagnosis of PTL was made using appropriate diagnostic criteria for the 2008 WHO classification of lymphoid tumors with combinations of histologic, immunohistochemical, flow cytometric, and genetic evaluation. Medical records were reviewed for demographic and clinical data. We performed whole-exome next-generation sequencing (NGS) and mapped the mutational landscape. Based on the differential gene results, we performed KEGG and GO enrichment analysis, and five potential new pathogenic genes for DLBCL were obtained based on the Polyphen score.Results:A total of 20 DLBCL samples were collected. All samples were subjected to whole-exome sequencing (WES). A standard bioinformatics analysis process was used to identify somatic mutations in each sample, and an average of 1200 somatic mutations was identified, involving an average of 420 mutated genes. (Figure 1.) More than 85% of the somatic mutations were found in only 1 sample, indicating that somatic mutations are highly heterogeneous. In the matched 13 cases, we validated common gene mutations that have been reported, including PIM1 53.84% (7/13), CD79B 38.46% (5/13), CDKN2A 15.38% (2/13), and MYD88 15.38% (2/13). Venn diagram shows that 25% of the mutated genes were specific to the relapsed sample. GO analysis (Figure 2) shows the functional enrichment and differences between relapsed and non-relapsed samples. Non-relapsed samples are enriched in the herpes simplex virus 1 infection pathway. (Figure 3). Focusing on relapsed/non-relapsed samples, we identified 12 mutated genes specific to relapsed samples. Mutation Polyphen scores were calculated to assess mutation deleteriousness. Five potential new pathogenic genes for DLBCL were obtained.Conclusions:Based on whole-sequencing data, we validated the previously reported common genes for PTDLBCL. In addition, we performed GO and KEGG analysis according to the relapsed and non-relapsed groups. In addition, based on the difference in enrichment results, 12 significantly enriched mutated genes in relapsed DLBCL samples are obtained, and mutation Polyphen scores are calculated to assess mutation deleteriousness. And 5 potential new pathogenic genes of DLBCL are identified. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

[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.

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.

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.

Relative Frequencies and Patterns of Malignant Lymphoma in a Reference Centre in Khartoum, Sudan: A Descriptive Study Based on the WHO Classification of Lymphoid Neoplasms

Background: The effective management and choice of appropriate treatment of lymphoma subtypes depend on an accurate diagnosis and differentiation, which require comprehensive haematology and pathology work. Methods: A total of 134 cases of malignant lymphoma, newly diagnosed between January 2017 to January 2020, were selected. For each patient’s samples, complete blood count, immunohistochemistry, and morphological evaluation were done. Results: Clinical data showed that 81 patients (60.4%) were males and 53 (39.6%) females. The age range was 4 to 80 years. NHL lymphoma comprised 87.3% of cases, while HL comprised 12.7% of cases. Diffuse large B cell lymphoma was the most prevalent NHL subtype, representing 39.3% of cases. Among HL subtypes, mixed cellularity was present in 41.2% of cases. B cell lymphoma constituted 93.2% of cases. All HL patients and 74.4% of NHL patients had anaemia. Conclusion: This is the first statistical report of malignant lymphoma patterns in Sudanese patients. These data suggest that malignant lymphoma in Sudanese patients is more frequent in males than females; its incidence increases with age. Further, B cell lymphoma is more common than T cell lymphoma. Diffuse large B cell lymphoma was the most frequent NHL subtype.

EBV-positive diffuse large B-cell lymphoma, not otherwise specified: 2020 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 2016 WHO classification of lymphoid neoplasms. EBV+ DLBCL, NOS, is an aggressive B-cell lymphoma associated with chronic 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 positivity has not been defined. The differential diagnosis includes plasmablastic lymphoma (PBL), DLBCL associated with chronic inflammation and 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. There is an opportunity to study and develop targeted therapy in the management of patients with EBV+ DLBCL, NOS.

Non-Hodgkin's lymphoma: A review.

Lymphomas constitute the third most common neoplasm in head and neck region arising from the lymphoreticular system. Malignant lymphomas are divided into Hodgkin's disease and non-Hodgkin's lymphoma (NHL). NHL comprises approximately 5% of head and neck malignancies and displays a wide range of appearances comparable with Hodgkin's disease. Hodgkin's and non-Hodgkin's lymphomas are seen in the head and neck region, but extranodal disease, with or without lymph node involvement, is more common among NHL patients. Extranodal involvement includes the areas such as Waldeyer's ring (i.e., the tonsils, pharynx, and base of the tongue), salivary glands, orbit, paranasal sinuses, and thyroid glands. There are several classification systems for categorizing NHL out of which WHO classification for lymphoid neoplasms is mostly followed. This review describes the pathogenesis of NHL and explains some of the important NHL (Marginal zone B-cell Lymphoma, follicular lymphoma, mantle cell lymphoma).

Clonal B-Cell Lymphocytosis with Mariginal-Zone Features: Comparison with Overt Splenic Marginal-Zone Lymphomas in 77 Patients from a Monocentric Series

Diagnosis of non-CLL B Cell Chronic Lymphoproliferative Disorders (BCLPD), defined by the detection of peripheral blood (PB) B-Cell clone with flow cytometry (FC) Matutesscore≤3, is not an infrequent event in clinical daily practice. Only a portion of these cases may be actually classified according to the 2016 revision of WHO classification of lymphoid neoplasms, as in these cases a non-bone marrow (BM) tissue biopsy is rarely available due to "liquid-only disease" (BM, PB, splenomegaly) or difficult accessible sites. The two most likely diagnosis of BCLPD according to WHO 2016 are splenic marginal-zone lymphoma (SMZL) and monoclonal B Cell lymphocytosis (MBL) with non-CLL phenotype (CD19+, CD20+, SIg+, CD5-), sometimes reported as MZL-like, defined by monotypic clonal B lymphocytes (CBL) <5 x 109/l. A recent study pointed out a similar outcome regardless CBL value exceeding or not this arbitrary cut-off in strictly defined cases (absence of cytopenias, splenomegaly and adenopathy) of clonal B cell lymphocytosis with marginal-zone features (CBL-MZ) and confirmed the really indolent behaviour of this entity (Xochelli, Blood 2014). On these bases we decided to retrospectively collect clinical, immunophenotypic, molecular features and outcome of all consecutive patients (pts) with CD5- CBL-MZ owing to the Department of Hematology of University of Insubria (Varese, Italy) from 2011 to 2019 and to compare them with overt SMZL cases. Excluding 5 SMZL pts who were splenectomized, all cases were diagnosed by means of non-BM tissue biopsy, namely BM histology and PB/BM FC, FISH and molecular studies, when appropriate, and complete laboratory and imaging staging procedures (CT scan or US). The primary objective of the study was time to progression (TTP) for CBL-MZ group. Secondary objectives were overall survival (OS), progression-free survival (PFS) for treated pts and evaluation of early progression <24 months (Early POD) (Luminari, Blood 2019). Overall we collected complete data of 33 pts with CD5- CBL-MZ, and 44 with SMZL (Table 1). Focusing on CBL-MZ, FC immunophenotypic findings showed a B-Cell population with Matutes score 0 to 2 in all cases, uniform expression of B Cell antigens, namely CD19, CD20 strong, FMC7 (93%), SIg (intermediate/bright in 71%), while CD10 and CD5 were consistently negative. CD23 was expressed in 18%, CD38 in 9% and CD49b in 95%. BM sinusoidal infiltration pattern was detected in 50% of cases. TP53 mutation/deletion was detected in 4/16 pts (25%) while trisomy 12 and del13q in 1 pt each. Twenty pts presented with <5000/mmc CBL (MBL-MZ) and 13 with ≥5000/mmc CBL. With a median follow-up of 1.8 years, 6 pts (18%) progressed (4 in SMZL, 1 NMZL and 1 SLL; Fig 2) with a median TTP of 1.7 yrs (range 0.3- 12.3), while the remaining 27 remained completely stable. Among 4 pts treated, 2 received Rituximab-based regimen, both achieving CR and 2 with Chlorambucil both experiencing progression. Overall, 5 pts died (2 for progressive lymphoma), with an estimated 5-yrs of 80%. Concerning prognostic factors, after adjusting by competing risk method, at univariate analysis age >60 yrs, CBL >5000/mmc and albumin <3.5 g/dl, were associated to shorter TTP, while age >60 yrs, Hb <11 g/dl, ECOG PS ≥2 and albumin <3.5 g/dl resulted predictive of worse OS (Table 2). By applying multivariate Cox regression model, only age >60 yrs and CBL>5000/mmc retained prognostic significance for TTP (p<0.0001), while ECOG PS ≥2 and albumin <3.5 g/dl remained independently associated with inferior OS (p<0.0001). Considering the SMZL group, 34 pts underwent systemic treatment (rituximab-based in 32, including R-Bendamustine in 17). With a median follow-up time of 2.8 yrs, 9 pts progressed (4 of whom within 24 months from treatment initiation), with a median PFS 2.9 yrs, and 8 died (7 due to progression, including 3 DLBCL transformations) with an estimated 5-yrs OS of 79%. Notably, Early POD SMZL pts exhibited a significant increased risk of death (p<0.0001, fig.2), while in CBL-MZ did not (p=0.4). In conclusion, CBL-MZ confirmed to be associated with indolent course and preferential evolution toward SMZL, of which it can be viewed as an initial phase or a precursor entity. In contrast with previous findings, the WHO 16 CBL cut-off defining MBL (5 x 109/l), together with advanced age, retained prognostic relevance for TTP. Finally, we confirmed for the first time in an independent series of SMZL the highly prognostic impact of Early POD24. Disclosures Passamonti: Roche: Consultancy; Janssen: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau; Novartis: Consultancy, Honoraria, Speakers Bureau.

Primary Cutaneous Acral CD8+ T-Cell Lymphoma—A Single Center Review of 3 Cases and Recent Literature Review

The recently published 2016 revision of the WHO classification of lymphoid neoplasms includes primary cutaneous acral CD8-positive T-cell lymphoma (PCATCL) as a provisional entity. This is a rare indolent lymphoma characterized by papules or nodules on the ear and a dermal infiltrate of CD8-positive T-lymphocytes with cytotoxic marker expression. A retrospective review of a single institutional experience with PCATCL identified 3 patients (mean age 54; range 49-62) with papules or nodules on the ear. Lesional biopsies demonstrated a dense diffuse dermal infiltrate of atypical lymphocytes with a Grenz zone in 2 cases and focal epidermotropism in 1 case. The atypical lymphocytes were predominantly CD3 and CD8 positive with expression of cytotoxic marker TIA1. Staging evaluation failed to reveal systemic disease. Two patients underwent local excision, and the third received local radiation therapy all with complete response and no disease recurrence at last follow-up 3 months (range 2-5 months). Our cases add to the existing limited literature on the clinical and histopathological features of PCATCL. We also performed an updated systematic literature view of the entity.

'NOT SO CLASSICAL': A STUDY OF THE IMMUNOPROFILE IN CLASSICAL HODGKIN LYMPHOMA, AN EXPERIENCE FROM A REFERRAL CENTER

Introduction: According to WHO classification, Classical Hodgkin Lymphoma (CHL) expresses CD15 and CD30 antigens in majority of cases, and CD20 in a small subset of cases. Expression of CD20 may affect the patients' prognosis, relapse, and refractoriness to the therapy. We come across a subset of cases of CHL in our lymphoma consultation cases that exhibit a lack of the ‘positive’ diagnostic marker CD15 and express CD20 in the Hodgkin and Reed-Sternberg (HRS) cells. This observation has important prognostic implication, based on the western studies from the more developed world, and furthermore prompted us for a systematic evaluation of the immunoprofile of South-East Asian CHL patients and to compare those with the Western data. Methods: In this retrospective analysis, 111 cases of CHL diagnosed over a period of six months were studied. Demographics, clinical details, histopathological (including unusual morphologic patterns), and immunohistochemical (IHC) parameters were recorded. The diagnoses were made according to the 2016 WHO classification of lymphoid neoplasms. The cases were further subtyped. The IHC panel included CD45, CD15, CD30, CD3, CD20, PAX5, ALK1, and EBV (LMP-1) in all cases and MUM1, CD21, EMA, PD1, OCT2, BOB.1, and BCL6, in a subset of cases, wherever necessary. A case was designated CD20+, if >10% of HRS cells were strongly positive. Results: The cases of CHL fit into 'textbook phenotype' (WHO 2016 update) of CD15+, CD30+, CD20- in 54% cases. HRS cells were positive for CD30 in all, CD15 in 56%, PAX5 in 96%, CD20 in 18% cases and EBV (LMP1) in 58.3% cases. In majority of instances, morphology and an initial panel of CD3, CD20, CD15, CD30, CD45, and PAX5 were sufficient for diagnosis. When IHC pattern discordance was noted or mimics of CHL were in the differential diagnostic consideration, additional markers supported the diagnosis of CHL. Conclusions: 1. Our study results broaden the understanding of the demographic, histopathologic, and IHC characteristics of CHL cases. 2. The second peak of bimodal distribution occurs two decades earlier as compared to those of the western population in majority cases in our cohort. 3. 56% of our cases expressed CD15 that is lower than the reported positivity rates (75% to 85%). 4. Significant CD20 positivity in HRS cells as seen in our cohort can create diagnostic dilemma. However, CD45 negativity in the presence of weak to barely perceptible PAX5 and moderate to strong expression for EBV aid in arriving at a diagnosis of CHL. 5. Future directions: The management of CHL is essentially based on radiotherapy and chemotherapy, due to lack of information about the clinical outcomes with anti-CD20 antibody therapy or combined drug therapy using a classic regimen. The prognostic impact of lack of CD15 and positive CD20 expression in the cases of CHL requires further research and clinical follow-up studies in a larger cohort of patient to assess the role of CD20 in the pathophysiology and progression of CHL. Keywords: CD20; classical Hodgkin lymphoma (cHL); immunohistochemistry (IHC).