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

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.

Assessment for 11q and other chromosomal aberrations in large B-cell/high-grade B cell lymphomas of germinal center phenotype lacking BCL2 expression

The WHO classifications of hematolymphoid malignancies have recognized several distinct entities within the large B cell lymphomas, including the more recently described high-grade B cell lymphoma with 11q aberration (HGBCL-11q). We utilized genomic array to assess for chromosome 11q abnormalities in a broad set of aggressive B cell lymphomas from 27 patients with a focus on younger adults. The findings suggest more frequent alterations of 11q in diffuse large B cell lymphoma (DLBCL)/HGBCL-GC BCL2-, in comparison to cases of Burkitt lymphoma (BL) or DLBCL-GC BCL2+, and confirm a low genomic complexity score of BL. Variability identified in patterns of 11q alterations suggests genomic array studies may afford value over FISH testing as we continue to understand HGBCL-11q as a distinct entity, and interrogate cases of DLBCL/HGBCL-GC BCL2-.

The fifth edition of the WHO classification of mature B-cell neoplasms: open questions for research

The fifth edition of the World Health Organization Classification of Haematolymphoid Tumours (WHO-HAEM5) is the product of an evidence-based evolution of the revised fourth edition with wide multidisciplinary consultation. Nonetheless, while every classification incorporates scientific advances and aims to improve upon the prior version, medical knowledge remains incomplete and individual neoplasms may not be easily subclassified in a given scheme. Thus, optimal classification requires ongoing study, and there are certain aspects of some entities and subtypes that require further refinements. In this review, we highlight a selection of these challenging areas to prompt more research investigations. These include (1) a 'placeholder term' of splenic B-cell lymphoma/leukaemia with prominent nucleoli (SBLPN) to accommodate many of the splenic lymphomas previously classified as hairy cell leukaemia variant and B-prolymphocytic leukaemia, a clear new start to define their pathobiology; (2) how best to classify BCL2 rearrangement negative follicular lymphoma including those with BCL6 rearrangement, integrating the emerging new knowledge on various germinal centre B-cell subsets; (3) what is the spectrum of non-IG gene partners of MYC translocation in diffuse large B-cell lymphoma/high-grade B-cell lymphoma and how they impact MYC expression and clinical outcome; how best to investigate this in a routine clinical setting; and (4) how best to define high-grade B-cell lymphoma not otherwise specified and high-grade B-cell lymphoma with 11q aberrations to distinguish them from their mimics and characterise their molecular pathogenetic mechanism. Addressing these questions would provide more robust evidence to better define these entities/subtypes, improve their diagnosis and/or prognostic stratification, leading to better patient care. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Aggressive B-cell non-Hodgkin lymphomas: a report of the lymphoma workshop of the 20th meeting of the European Association for Haematopathology

Aggressive B-cell non-Hodgkin lymphomas are a heterogeneous group of diseases and our concepts are evolving as we learn more about their clinical, pathologic, molecular genetic features. Session IV of the 2020 EAHP Workshop covered aggressive, predominantly high-grade B-cell lymphomas, many that were difficult to classify. In this manuscript, we summarize the features of the submitted cases and highlight differential diagnostic difficulties. We specifically review issues related to high-grade B-cell lymphomas (HGBCLs) with MYC and BCL2 and/or BCL6 rearrangements including TdT expression in these cases, HGBCL, not otherwise specified, large B-cell lymphomas with IRF4 rearrangement, high-grade/large B-cell lymphomas with 11q aberration, Burkitt lymphoma, and pleomorphic mantle cell lymphoma. Since the workshop, the 5th edition of the WHO Classification for Haematolymphoid Tumours (WHO-HAEM5) and International Consensus Classification (ICC) 2022 were published. We endeavor to use the updated terminology.

Cytogenomics of B-cell non-Hodgkin lymphomas: The "old" meets the "new"

For the routine diagnosis of haematological neoplasms an integrative approach is used considering the morphology, and the immunophenotypic, and molecular features of the tumor sample, along with clinical information. The identification and characterization of recurrent chromosomal aberrations mainly detected by conventional and molecular cytogenetics in the tumor cells has a major impact on the classification of lymphoid neoplasms. Some of the B-cell non-Hodgkin lymphomas are characterized by particular chromosomal aberrations, highlighting the relevance of conventional and molecular cytogenetic studies in their diagnosis and prognosis. In the current genomics era, next generation sequencing provides relevant information as the mutational profiles of haematological malignancies, improving their classification and also the clinical management of the patients. In addition, other new technologies have emerged recently, such as the optical genome mapping, which can overcome some of the limitations of conventional and molecular cytogenetics and may become more widely used in the cytogenetic laboratories in the upcoming years. Moreover, epigenetic alterations may complement genetic changes for a deeper understanding of the pathogenesis underlying B-cell neoplasms and a more precise risk-based patient stratification. Overall, here we describe the current state of the genomic data integrating chromosomal rearrangements, copy number alterations, and somatic variants, as well as a succinct overview of epigenomic changes, which altogether constitute a comprehensive diagnostic approach in B-cell non-Hodgkin lymphomas.

[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.

Cytogenomic features of Richter transformation

BACKGROUND

Richter transformation (RT) is the development of aggressive lymphoma in patients with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL). This rare disease is characterised by dismal prognosis. In recent years, there has been a deeper understanding of RT molecular pathogenesis, and disruptions of apoptosis (TP53) and proliferation (CDKN2A, MYC, NOTCH1) has been described as typical aberrations in RT.

RESULTS

A single-institution cohort of 33 RT patients were investigated by karyotyping, fluorescence in situ hybridization and single nucleotide polymorphism/copy number (CN) arrays. Most of RTs were typically manifested by diffuse large B-cell lymphoma, not otherwise specified, among the remaining cases one was classified as high-grade B-cell lymphoma with 11q aberrations. The most frequent alterations (40-60% of cases) were represented by MYC rearrangement/gain, deletions of TP53 and CDKN2A, IGH rearrangement and 13q14 deletion. Several other frequent lesions included losses of 14q24.1-q32.33, 7q31.33-q36.3, and gain of 5q35.2. Analysis of 13 CLL/SLL-RT pairs showed that RT arised from the CLL/SLL by acquiring of 10 ~ 12 cytogenetic or CN lesions/case, but without acquisition of loss of heterozygosity regions. Our result affirmed the higher genetic complexity in RT than CLL/SLL and confirmed the linear features of RT clonal evolution as predominant.

CONCLUSIONS

Cytogenomic profile was concordant with the literature data, however the role of IGH rearrangement, 14q deletion and 5q35.2 gain need to be explored. We anticipate that further characterization of RT lesions will probably facilitate better understanding of the RT clonal evolution.

Cytogenetics in the management of mature B-cell non-Hodgkin lymphomas: Guidelines from the Groupe Francophone de Cytogénétique Hematologique (GFCH)

Non-Hodgkin lymphomas (NHL) consist of a wide range of clinically, phenotypically and genetically distinct neoplasms. The accurate diagnosis of mature B-cell non-Hodgkin lymphoma relies on a multidisciplinary approach that integrates morphological, phenotypical and genetic characteristics together with clinical features. Cytogenetic analyses remain an essential part of the diagnostic workup for mature B-cell lymphomas. Karyotyping is particularly useful to identify hallmark translocations, typical cytogenetic signatures as well as complex karyotypes, all bringing valuable diagnostic and/or prognostic information. Besides the well-known recurrent chromosomal abnormalities such as, for example, t(14;18)(q32;q21)/IGH::BCL2 in follicular lymphoma, recent evidences support a prognostic significance of complex karyotype in mantle cell lymphoma and Waldenström macroglobulinemia. Fluorescence In Situ Hybridization is also a key analysis playing a central role in disease identification, especially in genetically-defined entities, but also in predicting transformation risk or prognostication. This can be exemplified by the pivotal role of MYC, BCL2 and/or BCL6 rearrangements in the diagnostic of aggressive or large B-cell lymphomas. This work relies on the World Health Organization and the International Consensus Classification of hematolymphoid tumors together with the recent cytogenetic advances. Here, we review the various chromosomal abnormalities that delineate well-established mature B-cell non-Hodgkin lymphoma entities as well as newly recognized genetic subtypes and provide cytogenetic guidelines for the diagnostic management of mature B-cell lymphomas.

Proteogenomic Profiling of High-Grade B-Cell Lymphoma With 11q Aberrations and Burkitt Lymphoma Reveals Lymphoid Enhancer Binding Factor 1 as a Novel Biomarker

High-grade B-cell lymphomas with 11q aberrations (HGBL-11q) represent a World Health Organization-defined group of lymphomas that harbor recurrent chromosome 11q aberrations involving proximal gains and telomeric losses. Although a limited number of HGBL-11q cases evaluated thus far appear to show a similar course and prognosis as Burkitt lymphoma (BL), many molecular differences have been appreciated, most notably the absence of MYC rearrangement. Despite biological differences between BL and HGBL-11q, histomorphologic and immunophenotypic distinction remains challenging. Here, we provide a comparative whole proteomic profile of BL- and HGBL-11q-derived cell lines, identifying numerous shared and differentially expressed proteins. Transcriptome profiling performed on paraffin-embedded tissue samples from primary BL and HGBL-11q lymphomas was additionally performed to provide further molecular characterization. Overlap of proteomic and transcriptomic data sets identified several potential novel biomarkers of HGBL-11q, including diminished lymphoid enhancer-binding factor 1 expression, which was validated by immunohistochemistry staining in a cohort of 23 cases. Altogether, these findings provide a comprehensive multimodal and comparative molecular profiling of BL and HGBL-11q and suggest the use of enhancer-binding factor 1 as an immunohistochemistry target to distinguish between these aggressive lymphomas.

Diagnosis and management of mature B-cell lymphomas in children, adolescents, and young adults

Mature B-cell lymphoma in children, adolescents and young adults comprises three major histological subtypes including in order of frequency Burkitt, germinal center diffuse large B-cell lymphoma and primary mediastinal B-cell lymphoma. The cure rate of the first two with aggressive short chemotherapy based on clinical grouping is ∼90% in resource rich countries. Recent data has shown that incorporation of immune therapy has enhanced event free survival in advanced patients. Future studies will address the possibility of reducing the burden of chemotherapy by substitution of immune based therapies.

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.

Modern Classification and Management of Pediatric B-cell Leukemia and Lymphoma

Although pediatric hematopathology overlaps with that of adults, certain forms of leukemia and lymphoma, and many types of reactive conditions affecting the bone marrow and lymph nodes, are unique to children. As part of this series focused on lymphomas, this article (1) details the novel subtypes of lymphoblastic leukemia seen primarily in children and described since the 2017 World Health Organization classification and (2) discusses unique concepts in pediatric hematopathology, including nomenclature changes and evaluation of surgical margins in selected lymphomas.

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.

Early orbital involvement in a rare diagnosis of Burkitt-like lymphoma with 11q aberration

Burkitt-like lymphoma with 11q aberration is a rare condition that poses a diagnostic challenge due to similarities with Burkitt's lymphoma. Due to the rarity of cases, no specific guidelines exist for therapy, and it is treated the same way as Burkitt's lymphoma. We present such a case with initial orbital involvement, an unusual manifestation. Our patient achieved remission with induction chemotherapy, although he will need regular follow-up given the paucity of information on long-term monitoring in these patients.

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.

Genomic profiling for clinical decision making in lymphoid neoplasms

With the introduction of large-scale molecular profiling methods and high-throughput sequencing technologies, the genomic features of most lymphoid neoplasms have been characterized at an unprecedented scale. Although the principles for the classification and diagnosis of these disorders, founded on a multidimensional definition of disease entities, have been consolidated over the past 25 years, novel genomic data have markedly enhanced our understanding of lymphomagenesis and enriched the description of disease entities at the molecular level. Yet, the current diagnosis of lymphoid tumors is largely based on morphological assessment and immunophenotyping, with only few entities being defined by genomic criteria. This paper, which accompanies the International Consensus Classification of mature lymphoid neoplasms, will address how established assays and newly developed technologies for molecular testing already complement clinical diagnoses and provide a novel lens on disease classification. More specifically, their contributions to diagnosis refinement, risk stratification, and therapy prediction will be considered for the main categories of lymphoid neoplasms. The potential of whole-genome sequencing, circulating tumor DNA analyses, single-cell analyses, and epigenetic profiling will be discussed because these will likely become important future tools for implementing precision medicine approaches in clinical decision making for patients with lymphoid malignancies.

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.

Cryptic MYC insertions in Burkitt lymphoma: New data and a review of the literature

The occurrence of MYC-negative Burkitt lymphoma (BL) has been discussed for many years. The real frequency of the MYC insertion in MYC-negative BL is still unknown. Fine-needle aspiration biopsies of 108 consecutive patients with clinicopathologically suspected BL (suspBL) were evaluated by flow cytometry, classical cytogenetics, and fluorescence in situ hybridization (FISH). We found 12 cases (11%) without the MYC rearrangement by FISH with a MYC breakapart probe: two patients (1.9%) with cryptic MYC/IGH fusion (finally diagnosed as BL) and 10 patients (9.3%) with 11q gain/loss (finally diagnosed as Burkitt-like lymphoma with 11q aberration). The exact breakpoints of the cryptic MYC/IGH were investigated by next-generation sequencing. The MYC insertions’ breakpoints were identified in PVT1 in the first case, and 42 kb upstream of 5′MYC in the second case. To date, a molecular characterization of the MYC insertion in BL has only been reported in one case. Detailed descriptions of our MYC insertions in a routinely and consecutively diagnosed suspBL cohort will contribute to resolving the issue of MYC negativity in BL. In our opinion, the presence of the MYC insertions in BL and other lymphomas might be underestimated, because routine genetic diagnostics are usually based on FISH only, without karyotyping.

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.

Molecular Update and Evolving Classification of Large B-Cell Lymphoma

Diffuse large B-cell lymphomas (DLBCLs) are aggressive B-cell neoplasms with considerable clinical, biologic, and pathologic diversity. The application of high throughput technologies to the study of lymphomas has yielded abundant molecular data leading to the identification of distinct molecular identities and novel pathogenetic pathways. In light of this new information, newly refined diagnostic criteria have been established in the fourth edition of the World Health Organization (WHO) consensus classification of lymphomas, which was revised in 2016. This article reviews the histopathological and molecular features of the various aggressive B-cell lymphoma subtypes included in the updated classification.

Pediatric hematolymphoid pathology in the gastrointestinal tract

Hematolymphoid processes involving the gastrointestinal tract in the pediatric and adolescent young adult (AYA) populations include processes occurring primarily within the gastrointestinal tract as well as systemic diseases with predilection for gastrointestinal involvement. Here, we present a focused review of reactive and neoplastic entities occurring in the pediatric and AYA age groups.

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.

A Diagnostic Approach to the Identification of Burkitt-like Lymphoma With 11q Aberration in Aggressive B-Cell Lymphomas

Rare cases of aggressive B-cell lymphomas with a morphology similar to Burkitt lymphoma (BL) present with the BL-typical immunophenotype, but lacked MYC translocation (MYC-negative Burkitt-like lymphoma: mnBLL). A proportion of those with an imbalance pattern in chromosome 11q has been designated Burkitt-like lymphoma with 11q aberration in the recent update of the World Health Organization (WHO) classification. Because of the problems in the identification of Burkitt-like lymphoma with 11q aberration, our goal was to retrospectively analyze their frequency in a cohort of "candidate" aggressive lymphomas (cohort 1, n=35) such as mnBLL (n=16), diffuse large B-cell lymphoma with similarities to Burkitt lymphoma (DLBCL-BL; n=3), high-grade B-cell lymphomas, not otherwise specified (NOS) (n=16), as well as in a cohort of MYC-negative diffuse large B-cell lymphoma NOS (cohort 2, n=62). In total, 17/33 cohort 1 cases (52%) harbored the typical 11q aberration pattern, predominantly those that had been classified as mnBLL (12/16, 75%), but also as DLBCL-BL (2/3, 67%) and high-grade B-cell lymphomas, NOS (3/14; 21%). The specimens with this typical 11q aberration pattern were usually negative for the BCL2 protein. Of interest and as a new finding, samples harboring the 11q aberration pattern were often characterized by strikingly coarse apoptotic debris within starry sky macrophages facilitating their recognition. In contrast, only 1 of 62 garden variety DLBCL, NOS was positive for the 11q aberration pattern. In 2 DLBCL-BL, a dual MYC translocation/11q aberration pattern was detected. As a diagnostic algorithm, we, therefore, propose analysis of 11q status in MYC-negative high-grade lymphomas with features of BL, especially showing BCL2 negativity and a conspicuous coarse apoptotic debris in starry sky macrophages.

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.

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.

Genomics of aggressive B-cell lymphoma

The growing body of genomic information collected and applied to mature aggressive B-cell lymphoma diagnosis and management has exploded over the last few years due to improved technologies with high-throughput capacity, suitable for use on routine formalin-fixed, paraffin-embedded tissue biopsies, and decreasing costs. These techniques have made evaluation of complete DNA sequences, RNA-expression patterns, translocations, copy-number alterations, loss of heterozygosity, and DNA-methylation patterns possible on a genome-wide level. This chapter will present a case of aggressive B-cell lymphoma and discuss the most important genomic abnormalities that characterize this group of entities in the recent update to the fourth edition of the World Health Organization (WHO) lymphoma classification system. Genomic abnormalities discussed will include those necessary for certain diagnoses such as translocations of MYC, BCL2, or BCL6; gene-expression-profiling categorization; the newly defined Burkitt-like lymphoma with 11q abnormalities; prognostic and predictive mutations, as well as tumor heterogeneity. Finally, our current practices for clinical triage of specimens with a potential diagnosis of aggressive B-cell lymphomas are also described. Options for treatment at relapse, in light of these genomic features, will be discussed in the third presentation from this session.

Diagnosis of Lymphoid Lesions in Limited Samples: A Guide for the General Surgical Pathologist, Cytopathologist, and Cytotechnologist

OBJECTIVES

Advances in interventional techniques allow obtaining samples from most body sites through minimally invasive procedures that yield limited samples. We provide practical guidelines for diagnosis of lymphoid lesions in these samples.

METHODS

Guidelines for selection of biopsy site and triage of the specimen according to results of rapid on-site evaluation (ROSE), and description of the advantages and limitations of currently available ancillary studies are described, based on the experience of the authors, complemented by a comprehensive review of the literature.

RESULTS

Five diagnostic categories are observed at ROSE: (1) preponderance of small cells, (2) large cells, (3) mixed small and large cells, (4) blast-like cells, and (5) rare large pleomorphic cells. Detailed description of the diagnostic work-up and subsequent classification for each of these groups is provided.

CONCLUSIONS

A definitive diagnosis of lymphoid neoplasms in limited samples is possible in most cases through correlation of morphology, ancillary studies, and clinical scenario.