Post-transplant molecularly defined Burkitt lymphomas are frequently MYC-negative and characterized by the 11q-gain/loss pattern

Dedicated diagnostic approaches for mature B-cell non-Hodgkin lymphomas occurring in children, adolescents, and young adults

Non-Hodgkin lymphoma (NHL) represents the fourth most common malignant disease among children and adolescents. Current disease classifications, including the most recent World Health Organization (WHO) classification and the International Consensus Classification (ICC), rely on a combination of clinical, epidemiological, histologic, immunophenotypic, and molecular data to define discrete clinicopathologic entities. There is growing evidence that children, adolescents, and young adults (CAYA) with B-cell NHL display unique clinical and epidemiologic characteristics. This may be explained by distinct age-related developmental plasticity, immune and haematopoietic repertoires, environmental exposures and social determinants of health, and germline or acquired genetic and molecular features, including those associated with inborn errors of immunity (IEI). Here, we discuss the unique clinical and biological characteristics of several distinct paediatric B-cell NHL types to indicate a path forward in classification of these CAYA NHL to optimally support multidisciplinary patient care and personalized treatment. We propose a potential "arising in CAYA" classification qualifier to denote the distinct clinicopathologic characteristics of B-cell NHLs that, otherwise, histologically and immunophenotypically resemble those arising in middle-aged and older adults. We also discuss how haemopathology diagnoses are evolving to incorporate the most current scientific knowledge into future classification systems of CAYA B-cell NHL.

microRNA Profile of High-Grade B-Cell Lymphoma with 11q Aberration

High-grade B-cell lymphoma with 11q aberration (HGBCL-11q) is a rare germi-nal centre lymphoma characterised by a typical gain/loss pattern on chromo-some 11q but without MYC translocation. It shares some features with Burkitt lymphoma (BL), HGBCLs and germinal centre-derived diffuse large B-cell lym-phoma, not otherwise specified (GCB-DLBCL-NOS). Since microRNA expression in HGBCL-11q remains unknown, we aimed to identify and compare the mi-croRNA expression profiles in HGBCL-11q, BL and in GCB-DLBCL-NOS. Next-generation sequencing (NGS)-based microRNA profiling of HGBCL-11q (n = 6), BL (n = 8), and GCB-DLBCL-NOS without (n = 3) and with MYC rearrange-ment (MYC-R) (n = 7) was performed. We identified sets of 39, 64, and 49 mi-croRNAs differentiating HGBCL-11q from BL, and from GCB-DLBCL-NOS without MYC-R, respectively. The expression levels of miR-223-3p, miR-193b-3p, miR-29b-3p, and miR-146a-5p consistently differentiated HGBCL-11q from both BL, GCB-DLBCL-NOS without MYC-R. In addition, HGBCL-11q presented greater heterogeneity in microRNA expression than BL. The expression profile of MYC-regulated microRNAs differed in HGBCL-11q and in BL, while also clearly distinguishing HGBCL-11q and BL from GCB-DLBCL-NOS. The microRNA pro-file of HGBCL-11q differs from those of BL and GCB-DLBCL-NOS, exhibiting greater heterogeneity compared to BL. The microRNA profile further supports that HGBCL-11q is a distinct subtype of B-cell lymphoma.

Immunodeficiency-related high-grade B-cell lymphoma with 11q aberration: Further evidence for a lymphoma entity from a patient with simultaneous papillary renal cell carcinoma following pediatric kidney transplant

Various aggressive lymphomas entities have been associated with immunodeficiency. To provide further evidence that also MYC-negative high-grade B-cell (formerly Burkitt-like) lymphoma with 11q aberrations comprises an immunodeficiency-related subtype, we here conducted a comprehensive pathological and genetic workup of a 25-year-old patient with this type of lymphoma and simultaneous papillary renal cell carcinoma. The patient developed both malignancies following extensive childhood immunosuppression and a kidney transplant. Germline and somatic genetic analyses included interphase cytogenetics, imbalance mapping, and exome sequencing. We identified potential germline-predisposition to inborn errors of immunity, kidney disease, and cancer, along with a germline region of homozygosity in 20q. Each tumor showed imbalances and single nucleotide variants typical for the respective diagnosis, with shared gains in the name-giving region in 11q, gain of the MYC gene in 8q24 and trisomy 12. While we can show that the imbalances in 8q and 11q arise from different mechanisms in both tumors, trisomy 12 involved gain of the same parental chromosome. Our findings corroborate the existence of a subtype of immunodeficiency-related high-grade B-cell lymphomas with 11q aberrations, provide further insights into its molecular pathogenesis, and reveal potential pitfalls in the molecular diagnosis of simultaneous tumors based on the technology applied.

High-grade B-cell lymphoma with 11q aberration in the HIV setting: a clinicopathological study of 10 cases and literature review

High-grade B-cell lymphoma with 11q aberration (HGBL-11q) is a distinct lymphoma entity according to the 5th edition of the WHO classification of hematolymphoid tumors. It lacks MYC translocation but carries proximal gains and/or telomeric losses of chromosome 11q. This rare type of B-cell lymphoma is less frequently reported in people living with HIV (PLWH), and its exact frequency remains unclear. Our goal was to retrospectively analyze its frequency in a cohort of aggressive B-cell lymphomas in PLWH, including Burkitt lymphoma (BL, n = 35), diffuse large B-cell lymphoma (DLBCL, n = 48), high-grade B-cell lymphoma, not otherwise specified (HGBL-NOS, n = 13), which was diagnosed as AIDS-related lymphoma (ARL) at our institution. In total, 10/96 (10.4%) cases harbored the typical 11q aberration pattern, predominantly those that had been classified as BL (6/35, 17.1%), DLBCL (2/48, 4.2%), and HGBL, NOS (2/13, 15.4%). We also evaluated 7 cases of AIDS-related HGBL-11q (AR-HGBL-11q) reported in the literature. The median age of our cohort was 35 years, and all the patients were male. Most cases (70%) had a history of HIV infection for over 1 year, and all were involved in lymph nodes (100%), frequently involved extranodal sites (60%), and Ann Arbor stage III/IV. In histomorphology, the cases exhibited diverse cytological features, reminiscent of BL (6 cases), DLBCL (2 cases), and HGBL (2 cases). A comparison of the combined cohort of 17 AR-HGBL-11q cases with 11 ARL cases that lacked both MYC rearrangement and 11q aberration at our institution showed that HGBL-11q cases were characterized by strikingly coarse apoptotic debris (P < 0.001), background rich in eosinophils (P = 0.002), higher expression of the germinal centre marker LMO2 (P = 0.080), lower expression of MUM1 (P = 0.004), BCL2 (P = 0.007), and LEF1 (P = 0.080), and lower positivity for EBER in situ hybridisation (P = 0.027). Notably, one case in our series was EBV-positive, a finding not previously reported in the literature. Furthermore, comparing the prognosis between these two groups, AR-HGBL-11q showed a relatively favorable prognosis (P = 0.15), although the difference was not statistically significant. We analyzed this rare lymphoma entity in the HIV setting and highlighted the importance of integrating histomorphological and immunophenotypic features in its diagnosis and classification.

Temporal Assessment of Protein Stability in Dried Blood Spots

The use of protein biomarkers in blood for clinical settings is limited by the cost and accessibility of traditional venipuncture sampling. The dried blood spot (DBS) technique offers a less invasive and more accessible alternative. However, protein stability in DBS has not been well evaluated. Herein, we deployed a quantitative LC-MS/MS system to construct proteomic atlases of whole blood, DBSs, plasma, and blood cells. Approximately 4% of detected proteins' abundance was significantly altered during blood drying into blood spots, with overwhelming disturbances in cytoplasmic fraction. We also reported a novel finding suggesting a decrease in the level of membrane/cytoskeletal proteins (SLC4A1, RHAG, DSC1, DSP, and JUP) and an increase in the level of proteins (ATG3, SEC14L4, and NRBP1) related to intracellular trafficking. Furthermore, we identified 19 temporally dynamic proteins in DBS samples stored at room temperature for up to 6 months. There were three declined cytoskeleton-related proteins (RDX, SH3BGRL3, and MYH9) and four elevated proteins (XPO7, RAN, SLC2A1, and SLC29A1) involved in cytoplasmic transport as representatives. The instability was governed predominantly by hydrophilic proteins and enhanced significantly with an increasing storage time. Our analyses provide comprehensive knowledge of both short- and long-term storage stability of DBS proteins, forming the foundation for the widespread use of DBS in clinical proteomics and other analytical applications.

EBV-Related Lymphoproliferative Diseases: A Review in Light of New Classifications

Epstein-Barr virus (EBV) is a prevalent virus that can be detected in the vast majority of the population. Most people are asymptomatic and remain chronically infected throughout their lifetimes. However, in some populations, EBV has been linked to a variety of B-cell lymphoproliferative disorders (LPDs), such as Burkitt lymphoma, classic Hodgkin lymphoma, and other LPDs. T-cell LPDs have been linked to EBV in part of peripheral T-cell lymphomas, angioimmunoblastic T-cell lymphomas, extranodal nasal natural killer/T-cell lymphomas, and other uncommon histotypes. This article summarizes the current evidence for EBV-associated LPDs in light of the upcoming World Health Organization classification and the 2022 ICC classification.

ETS1 Function in Leukemia and Lymphoma

ETS proto-oncogene 1 (ETS1) is a transcription factor (TF) critically involved in lymphoid cell development and function. ETS1 expression is tightly regulated throughout differentiation and activation in T-cells, natural killer (NK) cells, and B-cells. It has also been described as an oncogene in a range of solid and hematologic cancer types. Among hematologic malignancies, its role has been best studied in T-cell acute lymphoblastic leukemia (T-ALL), adult T-cell leukemia/lymphoma (ATLL), and diffuse large B-cell lymphoma (DLBCL). Aberrant expression of ETS1 in these malignancies is driven primarily by chromosomal amplification and enhancer-driven transcriptional regulation, promoting the ETS1 transcriptional program. ETS1 also facilitates aberrantly expressed or activated transcriptional complexes to drive oncogenic pathways. Collectively, ETS1 functions to regulate cell growth, differentiation, signaling, response to stimuli, and viral interactions in these malignancies. A tumor suppressor role has also been indicated for ETS1 in select lymphoma types, emphasizing the importance of cellular context in ETS1 function. Research is ongoing to further characterize the clinical implications of ETS1 dysregulation in hematologic malignancies, to further resolve binding complexes and transcriptional targets, and to identify effective therapeutic targeting approaches.

[Clinical study of mature B-cell lymphoma in 11 children with chromosome 11 long-arm abnormalities]

Objective: To explore the clinical, pathological, diagnostic, treatment, and prognostic features of children with mature B-cell lymphoma (MBCL) . Methods: This retrospective study included pediatric patients with MBCL with chromosome 11 long-arm abnormalities who were diagnosed and treated at our hospital from December 2018 to February 2023. Results: Among the 11 pediatric patients with MBCL, nine were male and two were female, with a median age of 9 (2-13) years and a median disease course of 1.8 (0.5-24) months. The clinical manifestations were cervical lymph node enlargement in four patients, nasal congestion and snoring in four patients, abdominal pain in two patients, and difficulty breathing in one patient. There were seven cases of Burkitt's lymphoma, two of follicular lymphoma, and two of advanced B-cell lymphoma according to the pathological morphology examination. No patients had central nervous system or bone marrow involvement, and no extensive metastasis was observed on B-ultrasound or positron emission tomography-computed tomography (PET/CT). One patient had a huge tumor lesion. The Revised International Pediatric Non-Hodgkin Lymphoma Staging System classified four patients as stage Ⅱ, five as stage Ⅲ, and two as stage Ⅳ. 11q probe detection showed five cases of 11q gain, three of 11q loss, and three of both gain and loss. FISH showed positive MYC expression in three patients, including eight with advanced B-cell lymphoma with 11q abnormalities and three with Burkitt's lymphoma with 11q abnormalities. According to the 2019 edition of the National Health Commission's diagnostic and treatment guidelines for invasive MBCL in children, one patient was classified as Group A, two as Group B, and eight as Group C. Early evaluation of the efficacy showed complete remission. After mid-term evaluation, the intensity of chemotherapy was reduced in Group B and Group C. Among two cases of chemotherapy, the remaining nine cases had a median follow-up of 32 (6-45) months, and none had event-related survival. Conclusion: The incidence of MBCL with 11q abnormalities in children is low, clinical symptoms are mild, and progression is slow. The absence of MYC, BCL2, BCL6 rearrangements, C-MYC negative and 11q abnormalities on FISH is an important diagnostic indicator, and reducing the intensity of chemotherapy can improve prognosis.

Emerging entities: high-grade/large B-cell lymphoma with 11q aberration, large B-cell lymphoma with IRF4 rearrangement, and new molecular subgroups in large B-cell lymphomas. A report of the 2022 EA4HP/SH lymphoma workshop

Emerging entities and molecular subgroups in large B-cell lymphomas (LBCLs) were discussed during the 2022 European Association for Haematopathology/Society for Hematopathology workshop in Florence, Italy. This session focused on newly recognized diseases and their diagnostic challenges. High-grade/large B-cell lymphoma with 11q aberration (HG/LBCL-11q) is defined by chromosome 11q-gains and telomeric loss. FISH analysis is recommended for the diagnosis. HG/LBCL-11q can occur in the setting of immunodeficiency, including ataxia-telangiectasia, and predominates in children. The morphological spectrum of these cases is broader than previously thought with often Burkitt-like morphology and coarse apoptotic bodies. It has a Burkitt-like immunophenotype (CD10+, BCL6+, BCL2-) but MYC expression is weak or negative, lacks MYC rearrangement, and is in contrast to Burkitt lymphoma 50% of the cases express LMO2. LBCL with IRF4 rearrangement (LBCL-IRF4) occurs mainly in the pediatric population but also in adults. LBCL-IRF4 has an excellent prognosis, with distinguishing molecular findings. IRF4 rearrangements, although characteristic of this entity, are not specific and can be found in association with other chromosomal translocations in other large B-cell lymphomas. Other molecular subgroups discussed included primary bone diffuse large B-cell lymphoma (PB-DLBCL), which has distinctive clinical presentation and molecular findings, and B-acute lymphoblastic leukemia (B-ALL) with IGH::MYC translocation recently segregated from Burkitt lymphoma with TdT expression. This latter disorder has molecular features of precursor B-cells, often tetrasomy 1q and recurrent NRAS and KRAS mutations. In this report, novel findings, recommendations for diagnosis, open questions, and diagnostic challenges raised by the cases submitted to the workshop will be discussed.

Decoding the molecular heterogeneity of pediatric monomorphic post-solid organ transplant lymphoproliferative disorders

Posttransplant lymphoproliferative disorders (PTLDs) represent a broad spectrum of lymphoid proliferations, frequently associated with Epstein-Barr virus (EBV) infection. The molecular profile of pediatric monomorphic PTLDs (mPTLDs) has not been elucidated, and it is unknown whether they display similar genetic features as their counterpart in adult and immunocompetent (IMC) pediatric patients. In this study, we investigated 31 cases of pediatric mPTLD after solid organ transplantation, including 24 diffuse large B-cell lymphomas (DLBCLs), mostly classified as activated B cell, and 7 cases of Burkitt lymphoma (BL), 93% of which were EBV positive. We performed an integrated molecular approach, including fluorescence in situ hybridization, targeted gene sequencing, and copy number (CN) arrays. Overall, PTLD-BL carried mutations in MYC, ID3, DDX3X, ARID1A, or CCND3 resembling IMC-BL, higher mutational burden than PTLD-DLBCL, and lesser CN alterations than IMC-BL. PTLD-DLBCL showed a very heterogeneous genomic profile with fewer mutations and CN alterations than IMC-DLBCL. Epigenetic modifiers and genes of the Notch pathway were the most recurrently mutated in PTLD-DLBCL (both 28%). Mutations in cell cycle and Notch pathways correlated with a worse outcome. All 7 patients with PTLD-BL were alive after treatment with pediatric B-cell non-Hodgkin lymphoma protocols, whereas 54% of patients with DLBCL were cured with immunosuppression reduction, rituximab, and/or low-dose chemotherapy. These findings highlight the low complexity of pediatric PTLD-DLBCL, their good response to low-intensity treatment, and the shared pathogenesis between PTLD-BL and EBV-positive IMC-BL. We also suggest new potential parameters that could help in the diagnosis and the design of better therapeutic strategies for these patients.

Large B-Cell Lymphomas in the 5th Edition of the WHO-Classification of Haematolymphoid Neoplasms-Updated Classification and New Concepts

The family/class of the large B-cell lymphomas (LBCL) in the 5th edition of the World Health Organization (WHO) classification of haematolymphoid tumors (WHO-HAEM5) features only a few major changes as compared to the 4th edition. In most entities, there are only subtle changes, many of them only representing some minor modifications in diagnostic terms. Major changes have been made in the diffuse large B-cell lymphomas (DLBCL)/high-grade B-cell lymphomas (HGBL) associated with MYC and BCL2 and/or BCL6 rearrangements. This category now consists of MYC and BCL2 rearranged cases exclusively, while the MYC/BCL6 double hit lymphomas now constitute genetic subtypes of DLBCL, not otherwise specified (NOS) or of HGBL, NOS. Other major changes are the conceptual merger of lymphomas arising in immune-privileged sites and the description of LBCL arising in the setting of immune dysregulation/deficiency. In addition, novel findings concerning underlying biological mechanisms in the pathogenesis of the different entities are provided.

High-grade B-cell lymphoma with concurrent MYC rearrangement and 11q aberrations: Clinicopathologic, cytogenetic and molecular characterization of 4 cases

High-grade B-cell lymphoma with 11q aberrations (LBL-11q) resembles Burkitt lymphoma (BL), is negative for MYC rearrangement, and harbors chromosome 11q aberrations. Rare cases of high-grade B-cell lymphoma with concurrent MYC rearrangement and 11q aberrations (HGBCL-MYC-11q) have been described. In this study we report the clinicopathologic, cytogenetic, and molecular findings in 4 such cases. Diagnoses were made on tissue or bone marrow biopsies. Karyotype, fluorescence in situ hybridization, genomic microarray analyses, and next-generation sequencing were performed. All patients were male (median age 39 years). Three cases were diagnosed as BL, while one was diagnosed as diffuse large B-cell lymphoma. Karyotypes (available in 2 patients) were complex. In one patient, copy number analysis showed gains at 1q21.1-q44 and 13q31.3, and loss of 13q34, abnormalities typically seen in BL. All of our cases showed two or more mutations that are recurrent in BL, including ID3, TP53, DDX3X, CCND3, FBXO1, and MYC. Two cases showed a GNA13 mutation, commonly seen in LBL-11q. Cases of HGBCL-MYC-11q display overlapping morphologic and immunophenotypic, as well as cytogenetic and molecular features between BL and LBL-11q, with a mutational landscape enriched for mutations recurrent in BL. Concurrent MYC rearrangement with 11q abnormalities is important to recognize especially since it has implications for their classification.

Burkitt lymphoma after solid-organ transplant: Treatment and outcomes in the paediatric PTLD collaborative

Burkitt lymphoma arising in paediatric post-solid-organ transplantation-Burkitt lymphoma (PSOT-BL) is a clinically aggressive malignancy and a rare form of post-transplant lymphoproliferative disorder (PTLD). We evaluated 35 patients diagnosed with PSOT-BL at 14 paediatric medical centres in the United States. Median age at organ transplantation was 2.0 years (range: 0.1-14) and age at PSOT-BL diagnosis was 8.0 years (range: 1-17). All but one patient had late onset of PSOT-BL (≥2 years post-transplant), with a median interval from transplant to PSOT-BL diagnosis of 4.0 years (range: 0.4-12). Heart (n = 18 [51.4%]) and liver (n = 13 [37.1%]) were the most frequently transplanted organs. No patients had loss of graft or treatment-related mortality. A variety of treatment regimens were used, led by intensive Burkitt lymphoma-specific French-American-British/Lymphomes Malins B (FAB/LMB), n = 13 (37.1%), and a low-intensity regimen consisting of cyclophosphamide, prednisone and rituximab (CPR) n = 12 (34.3%). Median follow-up was 6.7 years (range: 0.5-17). Three-year event-free and overall survival were 66.2% and 88.0%, respectively. Outcomes of PSOT-BL patients receiving BL-specific intensive regimens are comparable to reported BL outcomes in immunocompetent children. Multi-institutional collaboration is feasible and provides the basis of prospective data collection to determine the optimal treatment regimen for PSOT-BL.

High-grade B-cell lymphoma with 11q aberrations: A single-center study

High-grade B-cell lymphoma with 11q aberrations (HGBL-11q) has been classified for the first time as a high-grade mature B-cell neoplasm according to the 5th edition of the World Health Organization Classification of Tumors of Hematopoietic and Lymphoid Tissues. HGBL-11q is morphologically and immunohistochemically similar to Burkitt lymphoma (BL) or HGBL; it is characterized by gain in the 11q23.2-11q23.3 region and loss in the 11q24.1-qter region but it lacks MYC translocation. HGBL-11q is a rare tumor, and its exact frequency in Japan remains unclear. In this study, we classified 113 Germinal center B-cell (GCB) type aggressive B-cell lymphomas (BCLs), which were divided into BL, high-grade (HG), and large cell (LC) morphologies. We performed fluorescence in situ hybridization (FISH) to identify 11q aberrations. Nine patients had 11q aberrations (7.96%, 9/113), including six HGBL-11q. The age range was from 8 to 87 years, and all were male. Six out of 14 patients with HG morphology were diagnosed with HGBL-11q (6/14, 42.9%). HGBL-11q has been found to occur primarily in children and young adults but also in middle-aged and older adults. Patients with HG morphology without MYC translocation should undergo FISH for 11q aberrations regardless of age. However, the pathogenesis, clinical findings, and prognosis of HGBL-11q remain unclear. The accumulation of cases with an accurate HGBL-11q diagnosis in daily practice and accurate and detailed data on HGBL-11q will contribute to further understanding of 11q aberrations.

New concepts in EBV-associated B, T, and NK cell lymphoproliferative disorders

EBV-associated lymphoproliferative disorders (LPD) include conditions of B, T, and NK cell derivation with a wide clinicopathological spectrum ranging from indolent, self-limiting, and localized conditions to highly aggressive lymphomas. Since the 2016 World Health Organization (WHO) lymphoma classification, progress has been made in understanding the biology of the EBV-associated LPDs. The diagnostic criteria of EBV+ mucocutaneous ulcer and lymphomatoid granulomatosis have been refined, and a new category of EBV-positive polymorphic B cell LPD was introduced to encompass the full spectrum of EBV-driven B cell disorders. The differential diagnosis of these conditions is challenging. This report will present criteria to assist the pathologist in diagnosis. Within the group of EBV-associated T and NK cell lymphomas, a new provisional entity is recognized, namely, primary nodal EBV+ T or NK cell lymphoma. The EBV + T and NK cell LPDs in children have undergone major revisions. In contrast to the 2016 WHO classification, now four major distinct groups are recognized: hydroa vacciniforme (HV) LPD, severe mosquito bite allergy, chronic active EBV (CAEBV) disease, and systemic EBV-positive T cell lymphoma of childhood. Two forms of HV LPD are recognized: the classic and the systemic forms with different epidemiology, clinical presentation, and prognosis. The subclassification of PTLD, not all of which are EBV-positive, remains unaltered from the 2016 WHO classification. This review article summarizes the conclusions and the recommendations of the Clinical Advisory Committee (CAC), which are summarized in the International Consensus Classification of Mature Lymphoid Neoplasms.

A comparison of the International Consensus and 5th World Health Organization classifications of mature B-cell lymphomas

Several editions of the World Health Organization (WHO) classifications of lympho-hemopoietic neoplasms in 2001, 2008 and 2017 served as the international standard for diagnosis. Since the 4th WHO edition, here referred as WHO-HAEM4, significant clinico-pathological, immunophenotypic and molecular advances have been made in the field of lymphomas, contributing to refining diagnostic criteria of several diseases, to upgrade entities previously defined as provisional and to identify new entities. This process has resulted in two recent classifying proposals of lymphoid neoplasms, the International Consensus Classification (ICC) and the 5th edition of the WHO classification (WHO-HAEM5). In this paper, we review and compare the two classifications in terms of diagnostic criteria and entity definition, with focus on mature B-cell neoplasms. The main aim is to provide a tool to facilitate the work of pathologists, hematologists and researchers involved in the diagnosis and treatment of lymphomas.

Characteristics and Outcome of Post-Transplant Lymphoproliferative Disorders After Solid Organ Transplantation: A Single Center Experience of 196 Patients Over 30 Years

Post-transplant lymphoproliferative disorder (PTLD) is a rare but life-threatening complication after transplantation. In this retrospective, monocentric study we aimed to collect real life data regarding PTLD and determine the role of Epstein Barr Virus (EBV) status and year of diagnosis on prognosis. We identified 196 biopsy-proven PTLD after solid organ transplantation (SOT) diagnosed at the University Hospitals Leuven (Belgium) from 1989 to 2019. EBV status was positive in 61% of PTLD. The median overall survival (OS) was 5.7 years (95% CI: 2.99-11.1). Although EBV positivity was not significantly correlated with OS in multivariate analyses (HR: 1.44 (95% CI: 0.93-2.24); p = 0.10), subgroup analysis showed a significantly better median OS for EBV negative post-transplant diffuse large B-cell lymphoma (DLBCL) compared to EBV positive post-transplant DLBCL (8.8 versus 2.5 years respectively; p = 0.0365). There was a significant relation between year of PTLD diagnosis and OS: the more recent the PTLD diagnosis, the lower the risk for death (adjusted HR: 0.962 (95% CI: 0.931-0.933); p = 0.017). In conclusion, the prognosis of PTLD after SOT has improved in the past decades. Our analysis shows a significant relation between EBV status and OS in post-transplant DLBCL.

Genomic landscape of mature B-cell non-Hodgkin lymphomas - an appraisal from lymphomagenesis to drug resistance

BACKGROUND

Mature B-cell non-Hodgkin lymphomas are one of the most common hematological malignancies with a divergent clinical presentation, phenotype, and course of disease regulated by underlying genetic mechanism.

MAIN BODY

Genetic and molecular alterations are not only critical for lymphomagenesis but also largely responsible for differing therapeutic response in these neoplasms. In recent years, advanced molecular tools have provided a deeper understanding regarding these oncogenic drives for predicting progression as well as refractory behavior in these diseases. The prognostic models based on gene expression profiling have also been proved effective in various clinical scenarios. However, considerable overlap does exist between the genotypes of individual lymphomas and at the same time where additional molecular lesions may be associated with each entity apart from the key genetic event. Therefore, genomics is one of the cornerstones in the multimodality approach essential for classification and risk stratification of B-cell non-Hodgkin lymphomas.

CONCLUSION

We hereby in this review discuss the wide range of genetic aberrancies associated with tumorigenesis, immune escape, and chemoresistance in major B-cell non-Hodgkin lymphomas.

Burkitt-like lymphoma with 11q aberration confirmed by needle biopsy of the liver: A case report

BACKGROUND

Burkitt-like lymphoma with 11q aberration (BLL-11q) is a rare provisional lymphoma, and the majority of cases are usually diagnosed by excisional lymph node biopsy. Here we report a case of BLL-11q diagnosed by needle biopsy of the liver in order to improve further understanding of the disease, reduce misdiagnosis, and identify treatment regimens.

CASE SUMMARY

The patient was a 67-year-old male. He complained of increased frequency of stools for more than one year, periumbilical pain and discomfort exceeding 3 mo. A computed tomography scan suggested an appendiceal malignant tumor with multiple metastases of the peritoneum, omentum, and liver. Needle biopsy of liver nodules showed that the tumor cells were of median size, the shape was consistent, a small number of tumor cells were large, the “starry sky” pattern was evident, and some tissue cells showed multiple apoptotic debris with coarse particles. Immunohistochemistry was positive for CD20, CD10, BCL6, and MYC. The Ki-67 proliferation index was more than 95%. Molecular biological detection indicated a lack of MYC, BCL2 and BCL6 gene rearrangement with 11q aberration. Therefore, the diagnosis was BLL-11q of the liver. After eight courses of chemotherapy, the abdominal and pelvic peritoneal masses and liver nodules had almost disappeared. The patient recovered well after a follow-up period of more than 13 mo.

CONCLUSION

BLL-11q is rare, but patients treated with standard chemotherapy for Burkitt lymphoma can have a good prognosis. Reducing the dose of chemotherapy or developing specific therapies to prevent overtreatment may be considered, but more case studies are needed.

Burkitt Lymphoma After Cardiac Transplantation: Therapeutic Considerations

Postsolid organ transplant Burkitt lymphoma (PSOT-BL) is rare but more aggressive than other post-transplant lymphoproliferative disorders (PTLD). Little is known about optimal treatment and outcome of postcardiac transplant Burkitt lymphoma (BL). We report an 8-year-old boy with a history of heart transplant who developed Epstein-Barr virus positive, late-onset PSOT-BL. He was successfully treated with BL specific chemoimmunotherapy and cessation of baseline immunosuppression. In this pediatric case of PSOT-BL, the use of standard intensive pediatric based chemoimmunotherapy regimen without modifications was feasible, well tolerated and resulted in complete remission. Long-term toxicities need further study.

Aggressive B-cell lymphoma cases with 11q aberration patterns indicate a spectrum beyond Burkitt-like lymphoma

The recent characterization of a group of non-MYC rearranged aggressive B-cell lymphomas, resembling Burkitt lymphoma (BL), characteristically harboring a telomeric 11q loss or combined 11q proximal gains/loss pattern has led to the introduction of the provisional entity of Burkitt-like lymphoma with 11q aberration (BLL-11q). Prompted by the discovery of a telomeric 11q loss in an HIV+ high-grade B-cell lymphoma patient, we investigated an extended cohort of aggressive B-cell lymphomas, enriched for cases with histopathological features intermediate between DLBCL and BL, including double- and triple-hit lymphomas (n = 47), for 11q loss/combined 11q proximal gains/loss pattern by fluorescence in situ hybridization. We provide first evidence that 11q aberrations can be found in both BLL in the context of an underlying HIV infection as well as in high-grade B-cell lymphomas with MYC, BCL2, and/or BCL6 rearrangements. We therefore propose that the clinicopathological spectrum of malignancies carrying this aberration may be broader than previously assumed.

Defining and Treating High-grade B-cell lymphoma, NOS

High-grade B-cell lymphoma, not otherwise specified (HGBL, NOS) is a recently introduced diagnostic category for aggressive B-cell lymphomas. It includes tumors with Burkitt-like or blastoid morphology that do not have double-hit cytogenetics and that cannot be classified as other well-defined lymphoma subtypes. HBCL, NOS are rare and heterogeneous; most have germinal center B-cell phenotype, and up to 45% carry a single-hit MYC rearrangement, but otherwise they have no unifying immunophenotypic or cytogenetic characteristics. Recent analyses utilizing gene expression profiling (GEP) revealed that up to 15% of tumors currently classified as diffuse large B-cell lymphoma display a HGBL-like GEP signature, indicating a potential to significantly expand the HGBL category using more objective molecular criteria. Optimal treatment of HGBL, NOS is poorly defined due to its rarity and inconsistent diagnostic patterns. A minority of patients have early-stage disease which can be managed with standard RCHOP-based approaches with or without radiation. For advanced-stage HGBL, NOS, which often presents with aggressive, disseminated disease, high lactate dehydrogenase, and involvement of extranodal organs (including the central nervous system [CNS]), intensified Burkitt lymphoma-like regimens with CNS prophylaxis may be appropriate. However, many patients diagnosed at age > 60 years are not eligible for intensive immunochemotherapy. An improved, GEP and/or genomic-based pathologic classification that could facilitate HGBL-specific trials is needed to improve outcomes for all patients. In this review, we discuss the current clinicopathologic concept of HGBL, NOS, existing data on its prognosis and treatment, and delineate potential future taxonomy enrichments based on emerging molecular diagnostics.

Kidney Transplant T Cell-Mediated Rejection Occurring After Anti-CD19 CAR T-Cell Therapy for Refractory Aggressive Burkitt-like Lymphoma With 11q Aberration: A Case Report

Post-transplant lymphoproliferative disorder is a growing complication of kidney transplantation and is associated with a poor prognosis. Anti-CD19 chimeric antigen receptor (CAR) T-cell therapy is an important new treatment option modifying the outcome of refractory hematological cancers. Here, we report the case of a 40-year-old kidney transplant recipient who developed a Burkitt-like lymphoma with 11q aberration 5 years after transplantation. After 3 unsuccessful lines of chemotherapy, it was decided to treat the patient with anti-CD19 CAR T cells as a salvage therapy. Three months after CAR T-cell infusion, she experienced a grade IIB T cell-mediated rejection with severe tubulitis (T3), slight interstitial inflammation (I1), and severe intimal arteritis (V2) with blood suffusion. Among T cells infiltrating the graft, some of them expressed the anti-CD19 CAR. CAR T cells within the graft and in blood samples were also detected by droplet digital polymerase chain reaction. Function of the kidney transplant improved after corticosteroid treatment and remained stable. However, lymphoma progressed, with a massive pulmonary mass leading to the patient's death 10 months after CAR T-cell infusion.

Novel Biological Insights and New Developments in Management of Burkitt Lymphoma and High-Grade B-Cell Lymphoma

OPINION STATEMENT

Burkitt lymphoma (BL) is highly curable, and prompt institution of therapy is critical to achieving optimal outcomes. Although current "standard" approaches are very effective in disease eradication, treatment-related toxicity makes optimal delivery of curative therapy a challenge, especially in older and immunocompromised individuals. Reduced intensity approaches with fewer toxic complications have been the focus of some recent studies. A critical question is if they can replace "standard" approaches by maintaining high curability with improved tolerability. Additionally, new molecular insights in BL biology suggest that in the future, "targeted therapy" approaches may be feasible using small molecule inhibitors and novel strategies. Recently, a new category of aggressive lymphoma named "high-grade B-cell lymphoma (HGBL) with MYC and BCL2 and/or BCL6 translocations" has been recognized. This category overlaps clinically and biologically with BL and has an inferior prognosis compared to most B-cell lymphomas, and the optimal approach to its management remains, as yet, undefined. In this review, we discuss the current landscape of BL treatment including recent results with low-intensity regimens and also consider current approaches to HGBL. We also explore how recently elucidated novel biological insights in BL biology may shape future therapeutic directions including the use of novel cellular therapy approaches.

Burkitt-like lymphoma with 11q aberration in a patient with AIDS and a patient without AIDS: Two cases reports and literature review

Objective

The aim of this study is to evaluate the clinicopathological features and the treatment of the Burkitt-like lymphoma with 11q aberration.

Methods

We reported two patients with Burkitt-like lymphoma with 11q aberration: a 56-year-old man with AIDS (case 1) and a 37-year-old woman (case 2) without AIDS. The biopsy of cervical lymph nodes showed Burkitt-like morphologic and immunophenotypic features. But both of them lack MYC rearrangement and carry an 11q-arm aberration with proximal gains and/or telomeric losses. The diagnosis was confirmed by pathological morphology, immunohistochemistry, and fluorescence in situ hybridization.

Result

After a cycle of R-CTOEP (rituximab, cyclophosphamide, pirarubicin, vincristine, and prednisone) chemotherapy, case 1 refused to chemotherapy and radiotherapy and was followed up for 34 months without recurrence and new focus. Case 2 received R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) for two cycles and achieved PR (partial response). Then, the patient in case 2 received EPOCH (etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin) for three cycles, and the right cervical mass disappeared. She achieved complete response and was followed up for 16 months without recurrence and new focus.

Conclusion

Burkitt-like lymphoma with 11q abnormalities resembles Burkitt lymphoma morphologically but lacks MYC rearrangement and may have a better prognosis.

Identification of clinical molecular targets for childhood Burkitt lymphoma

Burkitt lymphoma (BL) is a malignant tumor in children. Although BL is generally curable, early relapse and refractoriness may occur. Some molecular indicators have been recently suggested for BL diagnosis, but large heterogeneity still exists. This study aimed at providing clinical molecular targets and methods that may help improve diagnosis and treatment of childhood BL. Only children patients were included in the study, and targeted gene sequencing was conducted to identify tumor specific mutations. The mRNA and protein level expression of potential target genes were measured by real-time PCR and immunohistochemistry. The relationship between BL specific gene mutation and differential expression with clinical features was analyzed. The results showed that i) detailed analysis of c-MYC/BCL2/BCL6 gene loci alteration and gene expression would help in accurate diagnosis and treatment determination of childhood BL; ii) loss-of-function mutations in SOCS1 or CIITA gene might be used as malignant markers for BL diagnosis and prognosis; iii) specific mutations of CD79A, MYD88, KLF2, DNMT3A and NFKBIE genes often concurrently existed in BL and showed association with benign clinical outcomes; iv) the high expression of MYC, TCF3 and loss-of-function ID3 genes in tumor may be potential therapeutic targets and could be used for treatment monitoring; and v) four MYC-translocation negative cases were re-defined as high-grade B-cell lymphoma-not otherwise specified (HGBL-NOS) but showed similar clinical outcomes and molecular features to other BL cases in the study, suggesting more studies needed to explore the molecular mechanisms and clinical significance of this provisional tumor entity.

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Detailed analysis of c-MYC/BCL2/BCL6 gene alteration and expression may help in accurate diagnosis and treatment;

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The MYC-translocation negative cases (HGBL-NOS) showed similar clinical outcomes and molecular features to other cases;

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Loss-of-function mutations of SOCS1 or CIITA gene could be used as malignant markers for diagnosis and prognosis;

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Concurrent mutations in CD79A, MYD88, KLF2, DNMT3A and NFKBIE genes associated with benign clinical outcomes;

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High expression of MYC, TCF3 and loss-of-function ID3 gene in tumor may be potential therapeutic targets.

[Fluorescence in situ hybridization in the diagnosis of aggressive B-cell lymphomas]

The introduction of new lymphoma entities that are defined by chromosomal rearrangements has led to changes concerning the diagnostic algorithms in routine hematopathology, particularly for the large group of aggressive B‑cell lymphomas. The new, genetically defined entity high-grade B‑cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements (double/triple hit lymphoma) is morphologically heterogenous and comprises lymphomas with the morphology of a diffuse large B‑cell lymphoma (DLBCL), but also cases with blastoid appearance as well as intermediate/Burkitt-like morphology. This implies a cytogenetic analysis for the final classification of aggressive lymphomas with DLBCL morphology, which constitute the most common lymphomas in daily practice. This analysis is currently most efficiently performed via a sequential fluorescence in situ hybridization (FISH) approach, with an initial MYC-FISH, that is followed (if required, i.e., if a MYC rearrangement is detected) by an analysis regarding a BCL2- and BCL6-chromosomal rearrangement. In addition, the update of the fourth edition of the WHO classification for hematopoietic neoplasms introduced additional lymphoma subgroups that are defined by chromosomal rearrangements, such as Burkitt-like lymphoma with 11q aberration as well as large B cell lymphoma with IRF4 rearrangement. Therefore, FISH currently plays an important role in the diagnostic armamentarium in routine diagnostic hematopathology.

Burkitt-Like Lymphoma with 11q Aberration: A Case Report and Review of a Rare Entity

Burkitt-like lymphoma with 11q aberration is a rare diagnostic entity commonly occurring in children and young adults with a nodal presentation. This entity shares many similar morphologic and immunophenotypic features with conventional Burkitt lymphoma and other aggressive B-cell lymphomas, making its recognition challenging. However, the presence of its characteristic 11q gain/loss pattern is helpful in the diagnosis. We report a case of Burkitt-like lymphoma presenting as a right neck mass in a 17-year-old female patient that demonstrated no improvement with antibiotic therapy. The neoplasm displayed a diffuse proliferation of intermediate-sized atypical lymphoid cells with prominent nucleoli in a background of apoptotic debris, morphologically raising concern for conventional Burkitt lymphoma. Subsequent immunohistochemical and cytogenetic studies established the most likely diagnosis of Burkitt-like lymphoma with 11q aberration. Though rare, Burkitt-like lymphoma exhibits significant morphologic overlap with other high-grade B-cell lymphomas, making it an important entity to consider on the differential diagnosis of these lesions.

Genetic progression of post-transplant Burkitt-like lymphoma case with 11q-Gain/Loss and MYC amplification

"Burkitt-like lymphoma with 11q aberration" is a new provisional entity in the latest revision of lymphoma's World Health Organization classification described as carrying the specific 11q-gain/loss aberration and lacking MYC rearrangement. Morphologically, phenotypically and by gene and microRNA expression profiling these lymphomas resemble Burkitt lymphoma. The 11q-gain/loss was also found in post-transplant patients with molecular Burkitt lymphoma signature without MYC rearrangement. Recent reports describe aggressive lymphomas with coexistence of 11q-gain/loss and MYC rearrangement. In this report we describe post-transplant Burkitt-like lymphoma with 11q aberration and MYC amplification. Genetic studies were conducted at two time points: before therapy and during progression. In both cytogenetic examinations, peculiar 11q-gain/loss was detected. Percentage of cells carrying MYC amplification increased from 2% at initial diagnosis to 97% during progression. The MYC amplification can functionally correspond to MYC translocation and to MYC overexpression. The presence of MYC amplification seems to increase the aggressiveness of the reported disease course, so even a small clone with this change should be indicated in cytogenetic result.

Experience with provisional WHO-entities large B-cell lymphoma with IRF4-rearrangement and Burkitt-like lymphoma with 11q aberration in paediatric patients of the NHL-BFM group

Large B-cell lymphoma with IRF4 rearrangement, and Burkitt-like lymphoma with 11q aberration are two provisional lymphoma entities in the 2017 revision of the WHO classification of lymphoid neoplasms. Despite being more frequent in young patients, knowledge regarding their true incidence and clinical features in unselected cohorts of paediatric and adolescent patients is limited. We screened for both entities among paediatric patients (<18 years of age) in the German NHL-BFM (Non-Hodgkin lymphoma Berlin-Frankfurt-Münster) group. Among follicular lymphomas and diffuse large B-cell lymphomas (DLBCL), 7/34 cases (21%) showed an IRF4 break-apart pattern by fluorescence in situ hybridisation (FISH) and are associated with stages I and II disease (P = 0·043). Among lymphomas morphologically resembling Burkitt lymphoma, DLBCL and high-grade B-cell lymphoma, unclassifiable, 13/102 cases (13%) lacked a MYC break-apart pattern but were positive for 11q proximal gain and telomeric loss by FISH. MYC-negative Burkitt-like lymphomas with the typical 11q gain-loss pattern by FISH were older (P = 0·004), showed less male predominance (P = 0·003), lower stage (P = 0·040), lower serum LDH level (P = 0·01) and less abdominal involvement (P = 0·008) compared to high grade B-cell lymphomas without 11q gain-loss pattern. Both entities showed excellent outcome with overall survival of 100% when managed according to NHL-BFM strategies and may provide candidates for future therapy de-escalation in clinical trials.

Application of 2016 WHO classification in the diagnosis of paediatric high-grade MYC-negative mature B-cell lymphoma with Burkitt-like morphological features

AIMS

Historically, there has been no consensus on the diagnostic classification of high-grade B-cell lymphoma (HGBCL) with morphological features of Burkitt lymphoma (BL) but no MYC gene rearrangement (MYC-negative). The 2016 WHO classification of tumours of haematopoietic and lymphoid tissues has shed some light on this field with the modification of the grey-zone lymphoma with features intermediate between BL and diffuse large B-cell lymphoma, and the creation of several new entities. The aim of this study was to investigate how the revised WHO classification affects our practice in diagnosing these lymphomas in children.

METHODS

We retrospectively reviewed cases of mature HGBCL diagnosed at our hospital between 2015 and 2018.

RESULTS

Among 14 mature HGBCL cases with BL morphological features, 11 showed MYC rearrangement consistent with BL and 3 were MYC-negative. Two MYC-negative cases showed regions of 11q gain and loss by microarray consistent with Burkitt-like lymphoma with 11q aberration (BLL-11q). The third MYC-negative case showed diffuse and strong MUM1 expression, translocation involving 6p25 by chromosome analysis and IRF4 rearrangement by fluorescence in situ hybridisation analysis consistent with large B-cell lymphoma with IRF4 rearrangement (LBL-IRF4). All patients were treated according to applicable chemotherapeutic protocols and achieved remission.

CONCLUSIONS

BLL-11q and LBL-IRF4, two newly defined entities, should be considered in paediatric MYC-negative mature HGBCL cases. Accurate diagnosis needs careful histopathological examination and proper cytogenetic testing. Since they have unique cytogenetic features, specific treatments for them may emerge in the future. Therefore, accurate diagnosis based on the 2016 WHO classification is clinically significant.

Burkitt-like lymphoma in a pediatric patient with familial adenomatous polyposis

Familial adenomatous polyposis (FAP) is an autosomal dominant condition that predisposes to multiple malignancies, most commonly colorectal carcinoma, but has rarely been associated with lymphoma. We discuss one patient found to have Burkitt-like Lymphoma (BLL) with 11q aberration in the setting of previously undiagnosed FAP. We review the literature of FAP and associated malignancies and the provisional WHO classification of Burkitt-like lymphoma with 11q aberration. Both FAP and Burkitt-like lymphoma with 11q aberration involve perturbation of the MYC network and this may provide insight into a connection between these two diagnoses. However, further study is needed to elucidate if there is an increased risk of BLL and other subtypes of lymphoma among patients with FAP in order to provide optimal counseling and surveillance for patients with FAP.

A combination of LMO2 negative and CD38 positive is useful for the diagnosis of Burkitt lymphoma

Background

To evaluate the clinical utility of LIM Domain Only 2 (LMO2) negative and CD38 positive in diagnosis of Burkitt lymphoma (BL).

Methods

LMO2 and CD38 expression determined by immunohistochemistry in 75 BL, 12 High-grade B-cell lymphoma, NOS (HGBL,NOS) and 3 Burkitt-like lymphomas with the 11q aberration.

Results

The sensitivity and specificity of LMO2 negative for detecting BL were 98.67 and 100%, respectively; those of CD38 positive were 98.67 and 66.67%, respectively. The sensitivity and specificity of a combination of both for detecting BL were 97.33 and 100%, respectively. In our study, the combined LMO2 negative and CD38 positive results had a higher area under the curve than either LMO2 negative or CD38 positive alone.

Conclusions

A combination of LMO2 negative and CD38 positive is useful for the diagnosis of Burkitt lymphoma.

The Tumor Microenvironment in Post-Transplant Lymphoproliferative Disorders

Post-transplant lymphoproliferative disorders (PTLDs) cover a broad spectrum of lymphoproliferative lesions arising after solid organ or allogeneic hematopoietic stem cell transplantation. The composition and function of the tumor microenvironment (TME), consisting of all non-malignant constituents of a tumor, is greatly impacted in PTLD through a complex interplay between 4 factors: 1) the graft organ causes immune stimulation through chronic antigen presentation; 2) the therapy to prevent organ rejection interferes with the immune system; 3) the oncogenic Epstein-Barr virus (EBV), present in 80% of PTLDs, has a causative role in the oncogenic transformation of lymphocytes and influences immune responses; 4) interaction with the donor-derived immune cells accompanying the graft. These factors make PTLDs an interesting model to look at cancer-microenvironment interactions and current findings can be of interest for other malignancies including solid tumors. Here we will review the current knowledge of the TME composition in PTLD with a focus on the different factors involved in PTLD development.

Burkitt-like lymphoma with 11q aberration: a germinal center-derived lymphoma genetically unrelated to Burkitt lymphoma

Burkitt-like lymphoma with 11q aberration is characterized by pathological features and gene expression profile resembling those of Burkitt lymphoma but lacks the MYC rearrangement and carries an 11q-arm aberration with proximal gains and telomeric losses. Whether this lymphoma is a distinct category or a particular variant of other recognized entities is controversial. To improve the understanding of Burkitt-like lymphoma with 11q aberration we performed an analysis of copy number alterations and targeted sequencing of a large panel of B-cell lymphoma-related genes in 11 cases. Most patients had localized nodal disease and a favorable outcome after therapy. Histologically, they were high grade B-cell lymphoma, not otherwise specified (8 cases), diffuse large B-cell lymphoma (2 cases) and only one was considered as atypical Burkitt lymphoma. All cases had a germinal center B-cell signature and phenotype with frequent LMO2 expression. The patients with Burkitt-like lymphoma with 11q aberration had frequent gains of 12q12-q21.1 and losses of 6q12.1-q21, and lacked common Burkitt lymphoma or diffuse large B-cell lymphoma alterations. Potential driver mutations were found in 27 genes, particularly involving BTG2, DDX3X, ETS1, EP300, and GNA13. However, ID3, TCF3, or CCND3 mutations were absent in all cases. These results suggest that Burkitt-like lymphoma with 11q aberration is a germinal center-derived lymphoma closer to high-grade B-cell lymphoma or diffuse large B-cell lymphoma than to Burkitt lymphoma.

The mutational landscape of Burkitt-like lymphoma with 11q aberration is distinct from that of Burkitt lymphoma

The new recently described provisional lymphoma category Burkitt-like lymphoma with 11q aberration comprises cases similar to Burkitt lymphoma (BL) on morphological, immunophenotypic and gene-expression levels but lacking the IG-MYC translocation. They are characterized by a peculiar imbalance pattern on chromosome 11, but the landscape of mutations is not yet described. Thus, we investigated 15 MYC-negative Burkitt-like lymphoma with 11q aberration (mnBLL,11q,) cases by copy-number analysis and whole-exome sequencing. We refined the regions of 11q imbalance and identified the INO80 complex-associated gene NFRKB as a positional candidate in 11q24.3. Next to recurrent gains in 12q13.11-q24.32 and 7q34-qter as well as losses in 13q32.3-q34, we identified 47 genes recurrently affected by protein-changing mutations (each ≥3 of 15 cases). Strikingly, we did not detect recurrent mutations in genes of the ID3-TCF3 axis or the SWI/SNF complex that are frequently altered in BL, or in genes frequently mutated in germinal center-derived B-cell lymphomas like KMT2D or CREBBP An exception is GNA13, which was mutated in 7 of 15 cases. We conclude that the genomic landscape of mnBLL,11q, differs from that of BL both at the chromosomal and mutational levels. Our findings implicate that mnBLL,11q, is a lymphoma category distinct from BL at the molecular level.

Clinical Impact of the 2016 Update to the WHO Lymphoma Classification

OPINION STATEMENT

The 2016 revision of the WHO classification of lymphoid neoplasms includes new entities along with a clearer definition of provisional and definitive subtypes based on better understanding of the molecular drivers of lymphomas. These changes impact current treatment paradigms and provide a framework for future clinical trials. Additionally, this update recognizes several premalignant or predominantly indolent entities and underscores the importance of avoiding unnecessarily aggressive treatment in the latter subsets.

Other immunomodulatory agent-related lymphoproliferative diseases: a single-center series of 72 biopsy-confirmed cases

Ongoing development of new drugs, as well as novel indications in the treatment of autoimmune diseases leads to the increasing use of immunomodulatory and immunosuppressive drugs. Immunomodulatory agent-related lymphoproliferative disorders are a known and potentially life threatening complication of chronic administration of these drugs, but are less well characterized compared with post-transplant lymphoproliferative disorders. The heterogeneous drug targets, various underlying disease indications, different drug combinations used and relatively low incidence render data collection and interpretation difficult. In this retrospective paper, we describe the clinicopathological characteristics of a larger single-center series of 72 immunomodulatory agent-related lymphoproliferative disorder cases. We divided the cases according to the therapy, administered in the year preceding diagnosis of a lymphoproliferative disorder, in an immunosuppressive drug, an immunomodulatory drug and a combination of immunosuppressive and immunomodulatory drugs group. We observed differences in "time to lymphoproliferative disorder development" with a shorter time for all the immunomodulatory drug-related cases combined (immunomodulatory and immunomodulatory + immunosuppressive = immunomodulatory-all) vs immunosuppressive-only (p = 0.0031). The proportion of malignant cases in patients receiving immunomodulatory therapy was, however, also significantly lower when compared with the immunosuppressive treated cases (43 vs 88%; p = 0.0184). The immunomodulatory/suppressive agent-related lymphoproliferative disorders were less often associated with the Epstein-Barr virus (EBV) (31 vs 66%; p = 1.829e-05) and the lymphoproliferative disorders incidence in the first year after immunomodulatory/immunosuppressive therapy initiation was lower (18 vs 41%; p = 0.04151)-compared with a published series of 140 post-transplant lymphoproliferative disorder cases from the same center. However, a similar histopathological spectrum from nondestructive, to polymorphic and monomorphic lesions as in post-transplant lymphoproliferative disorders is observed. With increasing use of immunosuppressive and especially immunomodulatory therapy, a higher incidence of immunomodulatory/suppressive agent-related lymphoproliferative disorders is to be expected. Life-long awareness for development of immunomodulatory/suppressive agent-related lymphoproliferative disorders with clinical follow-up and timely biopsies of suspicious lesions is required since these lymphoproliferative disorders arise both early after therapy initiation and many years later. Histopathological confirmation and correct classification is necessary to guide therapy and EBV ISH should be a part of routine pathological diagnostics.

A comprehensive flow-cytometry-based immunophenotypic characterization of Burkitt-like lymphoma with 11q aberration

We previously described a subset of MYC translocation-negative aggressive B-cell lymphomas resembling Burkitt lymphoma, characterized by proximal gains and distal losses in chromosome 11. In the 2016 WHO classification, these MYC-negative lymphomas were recognized as a new provisional entity, 'Burkitt-like lymphoma with 11q aberration'. Here we present an immunophenotype analysis of Burkitt-like lymphomas with 11q aberration. Cells were acquired by fine needle aspiration biopsy from 10 young adult patients, 80% of whom presented recurrence-free 5-year survival. Twenty-three MYC-positive Burkitt lymphomas, including three carrying both MYC rearrangement and 11q aberration, served as controls. By immunohistochemistry, all Burkitt-like lymphomas with 11q aberration were CD20+/CD10+/BCL6+/BCL2-/MUM1-/MYC+/EBV-, usually LMO2+/CD44-/CD43- and sometimes CD56+, and showed high proliferation rate. By flow cytometry, Burkitt-like lymphoma with 11q aberration immunophenotypically resembled MYC-positive Burkitt lymphoma, except for significantly (adjusted P<0.001) more frequent CD38^higher expression in Burkitt lymphoma (91% MYC-positive Burkitt lymphoma vs 10% Burkitt-like lymphoma with 11q aberration), more frequently diminished CD45 expression in Burkitt lymphoma (74% vs 10%), an exclusive CD16/CD56 and highly restricted CD8 expression in Burkitt-like lymphoma with 11q aberration (60% vs 0% and 40% vs 4%, respectively). We showed high diagnostic accuracy and effectiveness of flow cytometry in Burkitt lymphoma. CD16/CD56 expression without CD38^higher and the lack of CD16/CD56 with CD38^higher expression proves to be a reliable, fast, and cost-effective method for diagnosing 11q aberration and MYC rearrangements in CD10(+) aggressive lymphomas, respectively. In addition, we confirmed a pattern of an inverted duplication with telomeric loss of 11q, as a recurrent 11q abnormality, but one case presented alternative changes, possibly resulting in an equivalent molecular effect. Our findings reveal similarities along with subtle but essential differences in the immunophenotype of Burkitt-like lymphoma with 11q aberration and MYC-positive Burkitt lymphoma, important for the differential diagnosis, but also for understanding the pathogenesis of Burkitt-like lymphoma with 11q aberration.

The 11q-Gain/Loss Aberration Occurs Recurrently in MYC-Negative Burkitt-like Lymphoma With 11q Aberration, as Well as MYC-Positive Burkitt Lymphoma and MYC-Positive High-Grade B-Cell Lymphoma, NOS

Objectives

The latest revision of lymphoma’s World Health Organization classification describes the new provisional entity “Burkitt-like lymphoma with 11q aberration” (BLL, 11q) as lacking MYC rearrangement, but harboring the specific11q-gain/loss aberration. We report genetic characteristics of 11 lymphoma cases with this aberration.

Methods

Classical cytogenetics, fluorescence in situ hybridization (FISH), and single nucleotide polymorphism/array comparative genomic hybridization.

Results

The 11q aberrations were described as duplication, inversion, and deletion. Array comparative genomic hybridization showed two types of duplication: bigger than 50 megabase pairs (Mbp) and smaller than 20 Mbp, which were associated with bulky tumor larger than 20 cm and amplification of the 11q23.3 region, including KMT2A. Six cases revealed a normal FISH status of MYC and were diagnosed as BLL,11q. Five cases showed MYC rearrangement and were diagnosed as Burkitt lymphoma (BL) or high-grade B-cell lymphoma, not otherwise specified (HGBL, NOS).

Conclusions

The 11q-gain/loss is not specific for BLL, 11q, but occurs recurrently in MYC-positive BL and MYC-positive HGBL.

Clinical utility of recently identified diagnostic, prognostic, and predictive molecular biomarkers in mature B-cell neoplasms

Genomic profiling studies have provided new insights into the pathogenesis of mature B-cell neoplasms and have identified markers with prognostic impact. Recurrent mutations in tumor-suppressor genes (TP53, BIRC3, ATM), and common signaling pathways, such as the B-cell receptor (CD79A, CD79B, CARD11, TCF3, ID3), Toll-like receptor (MYD88), NOTCH (NOTCH1/2), nuclear factor-κB, and mitogen activated kinase signaling, have been identified in B-cell neoplasms. Chronic lymphocytic leukemia/small lymphocytic lymphoma, diffuse large B-cell lymphoma, follicular lymphoma, mantle cell lymphoma, Burkitt lymphoma, Waldenström macroglobulinemia, hairy cell leukemia, and marginal zone lymphomas of splenic, nodal, and extranodal types represent examples of B-cell neoplasms in which novel molecular biomarkers have been discovered in recent years. In addition, ongoing retrospective correlative and prospective outcome studies have resulted in an enhanced understanding of the clinical utility of novel biomarkers. This progress is reflected in the 2016 update of the World Health Organization classification of lymphoid neoplasms, which lists as many as 41 mature B-cell neoplasms (including provisional categories). Consequently, molecular genetic studies are increasingly being applied for the clinical workup of many of these neoplasms. In this review, we focus on the diagnostic, prognostic, and/or therapeutic utility of molecular biomarkers in mature B-cell neoplasms.

Molecular Testing of Lymphoproliferative Disorders: Current Status and Perspectives

Molecular pathologic testing plays an important role for the diagnosis, prognostication and decision of treatment strategy in lymphoproliferative disease. Here, we briefly review the molecular tests currently used for lymphoproliferative disease and those which will be implicated in clinical practice in the near future. Specifically, this guideline addresses the clonality test for B- and T-cell proliferative lesions, molecular cytogenetic tests for malignant lymphoma, determination of cell-of-origin in diffuse large B-cell lymphoma, and molecular genetic alterations incorporated in the 2016 revision of the World Health Organization classification of lymphoid neoplasms. Finally, a new perspective on the next-generation sequencing for diagnostic, prognostic, and therapeutic purpose in malignant lymphoma will be summarized.