Search

INTRODUCTION: Fluorescence in situ hybridization (FISH) is an essential ancillary study used to identify clinically aggressive subsets of large B-cell lymphomas that have MYC, BCL2, or BCL6 rearrangements. Small-volume biopsies such as fine needle aspiration biopsy (FNAB) and core needle biopsy (CNB) are increasingly used to diagnose lymphoma and obtain material for ancillary studies such as FISH. However, the performance of FISH in small biopsies has not been thoroughly evaluated or compared to surgical biopsies. METHODS: We describe the results of MYC, BCL2, and BCL6 FISH in a series of 222 biopsy specimens, including FNAB with cell blocks, CNBs, and surgical excisional or incisional biopsies from 208 unique patients aggregated from 6 academic medical centers. A subset of patients had FNAB followed by a surgical biopsy (either CNB or excisional biopsy) obtained from the same or contiguous anatomic site as part of the same clinical workup; FISH results were compared for these paired specimens. RESULTS: FISH had a low hybridization failure rate of around 1% across all specimen types. FISH identified concurrent MYC and BCL2 rearrangements in 20 of 197 (10%) specimens and concurrent MYC and BCL6 rearrangements in 3 of 182 (1.6%) specimens. The paired FNAB and surgical biopsy specimens did not show any discrepancies for MYC or BCL2 FISH; of the 17 patients with 34 paired cytology and surgical specimens, only 2 of the 49 FISH probes compared (4% of all comparisons) showed any discrepancy and both were at the BCL6 locus. One discrepancy was due to necrosis of the CNB specimen causing a false negative BCL6 FISH result when compared to the FNAB cell block that demonstrated a BCL6 rearrangement. DISCUSSION: FISH showed a similar hybridization failure rate in all biopsy types. Ultimately, MYC, BCL2, or BCL6 FISH showed 96% concordance when compared across paired cytology and surgical specimens, suggesting FNAB with cell block is equivalent to other biopsy alternatives for evaluation of DLBCL or HGBCL FISH testing.

In this article, we provide a review of large B-cell lymphomas (LBCLs), comparing the recently published fifth edition of the WHO classification and the International Consensus Classification (ICC) on hematolymphoid tumors. We focus on updates in the classification of LBCL, an heterogeneous group of malignancies with varying clinical behaviors and different pathological and molecular features, providing a comparison between the two classifications. Besides the well-recognized diagnostic role of clinical, morphological and immunohistochemical data, both classifications recognize the ever-growing impact of molecular data in the diagnostic work-up of some entities. The main aim is to offer a guide for clinicians and pathologists on how the new classifications can be applied to LBCL diagnosis in routine practice. In the first part of the paper, we review the following categories: LBLs transformed from indolent B-cell lymphomas, diffuse large B-cell lymphoma, not otherwise specified (DLBCL, NOS), double-hit/triple-hit lymphomas (DH/TH), high-grade large B-cell lymphoma, not otherwise specified (HGBCL, NOS), LBCL with IRF4 rearrangement, Burkitt lymphoma (BL) and HGBCL/LBCL with 11q aberration, focusing on the differences between the two classifications. In the second part of the paper, we provide a practical diagnostic algorithm when facing LBCLs in routine daily practice. [ABSTRACT FROM AUTHOR]

Introduction: Fluorescence in situ hybridization (FISH) is an essential ancillary study used to identify clinically aggressive subsets of large B-cell lymphomas that have MYC, BCL2, or BCL6 rearrangements. Small-volume biopsies such as fine needle aspiration biopsy (FNAB) and core needle biopsy (CNB) are increasingly used to diagnose lymphoma and obtain material for ancillary studies such as FISH. However, the performance of FISH in small biopsies has not been thoroughly evaluated or compared to surgical biopsies. Methods: We describe the results of MYC, BCL2, and BCL6 FISH in a series of 222 biopsy specimens, including FNAB with cell blocks, CNBs, and surgical excisional or incisional biopsies from 208 unique patients aggregated from 6 academic medical centers. A subset of patients had FNAB followed by a surgical biopsy (either CNB or excisional biopsy) obtained from the same or contiguous anatomic site as part of the same clinical workup; FISH results were compared for these paired specimens. Results: FISH had a low hybridization failure rate of around 1% across all specimen types. FISH identified concurrent MYC and BCL2 rearrangements in 20 of 197 (10%) specimens and concurrent MYC and BCL6 rearrangements in 3 of 182 (1.6%) specimens. The paired FNAB and surgical biopsy specimens did not show any discrepancies for MYC or BCL2 FISH; of the 17 patients with 34 paired cytology and surgical specimens, only 2 of the 49 FISH probes compared (4% of all comparisons) showed any discrepancy and both were at the BCL6 locus. One discrepancy was due to necrosis of the CNB specimen causing a false negative BCL6 FISH result when compared to the FNAB cell block that demonstrated a BCL6 rearrangement. Discussion: FISH showed a similar hybridization failure rate in all biopsy types. Ultimately, MYC, BCL2, or BCL6 FISH showed 96% concordance when compared across paired cytology and surgical specimens, suggesting FNAB with cell block is equivalent to other biopsy alternatives for evaluation of DLBCL or HGBCL FISH testing. [ABSTRACT FROM AUTHOR]

IntroductionFluorescence in situ hybridization (FISH) is an essential ancillary study used to identify clinically aggressive subsets of large B-cell lymphomas that have MYC, BCL2, or BCL6 rearrangements. Small-volume biopsies such as fine needle aspiration biopsy (FNAB) and core needle biopsy (CNB) are increasingly used to diagnose lymphoma and obtain material for ancillary studies such as FISH. However, the performance of FISH in small biopsies has not been thoroughly evaluated or compared to surgical biopsies.MethodsWe describe the results of MYC, BCL2, and BCL6 FISH in a series of 222 biopsy specimens, including FNAB with cell blocks, CNBs, and surgical excisional or incisional biopsies from 208 unique patients aggregated from 6 academic medical centers. A subset of patients had FNAB followed by a surgical biopsy (either CNB or excisional biopsy) obtained from the same or contiguous anatomic site as part of the same clinical workup; FISH results were compared for these paired specimens.ResultsFISH had a low hybridization failure rate of around 1% across all specimen types. FISH identified concurrent MYC and BCL2 rearrangements in 20 of 197 (10%) specimens and concurrent MYC and BCL6 rearrangements in 3 of 182 (1.6%) specimens. The paired FNAB and surgical biopsy specimens did not show any discrepancies for MYC or BCL2 FISH; of the 17 patients with 34 paired cytology and surgical specimens, only 2 of the 49 FISH probes compared (4% of all comparisons) showed any discrepancy and both were at the BCL6 locus. One discrepancy was due to necrosis of the CNB specimen causing a false negative BCL6 FISH result when compared to the FNAB cell block that demonstrated a BCL6 rearrangement.DiscussionFISH showed a similar hybridization failure rate in all biopsy types. Ultimately, MYC, BCL2, or BCL6 FISH showed 96% concordance when compared across paired cytology and surgical specimens, suggesting FNAB with cell block is equivalent to other biopsy alternatives for evaluation of DLBCL or HGBCL FISH testing.

Simple Summary: Double/triple-hit lymphomas (DHLs/THLs) are an aggressive type of high-grade B-cell lymphomas (HGBLs), characterized by translocations in MYC and BCL2/BCL6. DHL patients respond poorly to standard chemoimmunotherapy regimens; thus, timely and accurate diagnosis is of paramount importance for their proper clinical management. The standard technique used for the identification of these translocations is fluorescence in situ hybridization (FISH), which is not routinely performed at every medical center to all potential patients. In the current study, we employed an image-based, artificial intelligence, deep learning algorithmic tool for the identification of DHL/THL cases by analyzing scanned histopathological H&E-stained tissue slide images. Our preliminary results demonstrate high performances, suggesting the potential use of such a solution in the clinical workflow to support the management of HGBL patients. Deep learning applications are emerging as promising new tools that can support the diagnosis and classification of different cancer types. While such solutions hold great potential for hematological malignancies, there have been limited studies describing the use of such applications in this field. The rapid diagnosis of double/triple-hit lymphomas (DHLs/THLs) involving MYC, BCL2 and/or BCL6 rearrangements is obligatory for optimal patient care. Here, we present a novel deep learning tool for diagnosing DHLs/THLs directly from scanned images of biopsy slides. A total of 57 biopsies, including 32 in a training set (including five DH lymphoma cases) and 25 in a validation set (including 10 DH/TH cases), were included. The DHL-classifier demonstrated a sensitivity of 100%, a specificity of 87% and an AUC of 0.95, with only two false positive cases, compared to FISH. The DHL-classifier showed a 92% predictive value as a screening tool for performing conventional FISH analysis, over-performing currently used criteria. The work presented here provides the proof of concept for the potential use of an AI tool for the identification of DH/TH events. However, more extensive follow-up studies are required to assess the robustness of this tool and achieve high performances in a diverse population. [ABSTRACT FROM AUTHOR]

Objectives Malignant effusion is usually caused by metastatic carcinoma. Malignant lymphoma is often not included as a top differential diagnosis of malignant effusion. Here, we describe 3 cases of young female patients with no significant past medical history who presented with fluid overload and were diagnosed with high-grade B-cell lymphoma (HGBL). Methods We conducted histopathologic examination and immunophenotypic and cytogenetic analyses on three cases using immunohistochemistry, flow cytometry, fluorescence in situ hybridization (FISH), and karyotyping. We also included patients' clinical and radiological findings in our case reports. Results Histologic examination of the effusion samples showed numerous intermediate to large lymphoma cells with irregular nuclear contours and fine chromatin. The lymphoma cells were positive for CD10, CD20, BCL2, BCL6, and PAX5 and negative for CD34, cyclin D1, HHV-8, and TdT. In situ hybridization for Epstein-Barr virus (EBV)–encoded small RNAs was negative. The proliferation index by Ki-67 stain was more than 80%. Flow cytometry showed CD10-positive B cells with monotypic immunoglobulin light chain expression. Fluorescence in situ hybridization analysis demonstrated MYC , BCL2 , or BCL6 rearrangements. These 3 patients were diagnosed as having HGBL with double-/triple-hit rearrangements. Despite receiving aggressive chemotherapy, all 3 patients had a dismal clinical course, with 2 patients dying less than 2 years after initial diagnosis. Conclusions High-grade B-cell lymphoma should be considered in the differential diagnoses of malignant effusions. Flow cytometric and FISH analyses of the body fluid specimens are essential to reach an accurate and timely diagnosis. [ABSTRACT FROM AUTHOR]

Follicular lymphoma (FL), a generally indolent disease that derives from germinal center (GC) B cells, represents around 20–25% of all new lymphomas diagnosed in Western countries. The characteristic t(14;18)(q32;q21) translocation that places the BCL2 oncogene under control of the immunoglobulin heavy-chain enhancer occurs in pro- or pre-B cells. However, additional secondary alterations are required for the development of overt FL, which mainly affects genes involved in epigenetic and transcriptional regulation, signaling and B cell differentiation, the BCR/NF-κB pathway, and proliferation/apoptosis. On the other hand, new insights into the FL pathogenesis suggest that FL lacking the BCL2 translocation might be a distinct biological entity with genomic features different from the classical FL. Although FL is considered an indolent disease, around 10–20% of cases eventually transform to an aggressive lymphoma, usually a diffuse large B cell lymphoma, generally by a divergent evolution process from a common altered precursor cell acquiring genomic alterations involved in the cell cycle and DNA damage responses. Importantly, FL tumor cells require interaction with the microenvironment, which sustains cell survival and proliferation. Although the use of rituximab has improved the outlook of most FL patients, further genomic studies are needed to identify those of high risk who can benefit from innovative therapies. This review provides an updated synopsis of FL, including the molecular and cellular pathogenesis, key events of transformation, and targeted treatments.

Follicular lymphoma (FL), a generally indolent disease that derives from germinal center (GC) B cells, represents around 20–25% of all new lymphomas diagnosed in Western countries. The characteristic t(14;18)(q32;q21) translocation that places the BCL2 oncogene under control of the immunoglobulin heavy-chain enhancer occurs in pro- or pre-B cells. However, additional secondary alterations are required for the development of overt FL, which mainly affects genes involved in epigenetic and transcriptional regulation, signaling and B cell differentiation, the BCR/NF-κB pathway, and proliferation/apoptosis. On the other hand, new insights into the FL pathogenesis suggest that FL lacking the BCL2 translocation might be a distinct biological entity with genomic features different from the classical FL. Although FL is considered an indolent disease, around 10–20% of cases eventually transform to an aggressive lymphoma, usually a diffuse large B cell lymphoma, generally by a divergent evolution process from a common altered precursor cell acquiring genomic alterations involved in the cell cycle and DNA damage responses. Importantly, FL tumor cells require interaction with the microenvironment, which sustains cell survival and proliferation. Although the use of rituximab has improved the outlook of most FL patients, further genomic studies are needed to identify those of high risk who can benefit from innovative therapies. This review provides an updated synopsis of FL, including the molecular and cellular pathogenesis, key events of transformation, and targeted treatments. [ABSTRACT FROM AUTHOR]

Follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL) with concurrent BCL2 and IRF4 rearrangements are rare. It is unclear whether such cases should be classified as large B- cell lymphoma with IRF4 rearrangement or FL/DLBCL-not otherwise specified. We identified 5 adult patients (FL, N = 3 and FL/DLBCL, N = 2) with concurrent BCL2 and IRF4 rearrangements. The median age at presentation was 77 years, and three patients presented with advanced stage disease. Both nodal and extranodal sites were involved and involvement was not limited to head and neck region. With a median follow-up of 18 months, 1 patient died and 4 patients were alive, including 3 who received chemotherapy and 1 who was observed. The neoplasms were histologically heterogeneous, including grade 2 and 3 FL and DLBCL. Four cases coexpressed CD10, BCL6, BCL2 and MUM1/IRF4. The Ki67 labelling index ranged from 20% to 95%. In 4 patients, the percentage of cells with BCL2 rearrangement was equal to or slightly greater than the cells harboring IRF4 rearrangement. Two cases underwent next generation sequencing tailored for lymphoid neoplasms. Both lacked mutations involving IRF4 and NF-kB pathway genes that are frequently detected in large B-cell lymphoma with IRF4 rearrangement, and one case showed DLBCL-EZH2 type mutations, including KMT2D and BCL2 mutations, similar to 2 previously reported DLBCL with BCL2 and IRF4 rearrangements. Adults with FL and FL/DLBCL with BCL2 and IRF4 rearrangements display clinicopathologic and mutational features more akin to FL and DLBCL and should not be characterized as large B-cell lymphoma with IRF4 rearrangement., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Leukemic presentation of follicular lymphoma (FL) is uncommon, with most cases reported in older adults., Design: This report describes an unusual case of a young adult diagnosed with leukemic phase of FL. We reviewed the existing literature on this rare presentation of the disease and its potential impact on patient outcomes., Results: Leukemic phase of FL in young adults can be mistaken for other high-grade hematologic malignancies. Morphology assessment and ancillary testing, such as flow cytometry and FISH analysis, can assist in achieving an accurate diagnosis of the leukemic phase of FL. Notably, our young patient responded well to therapy, which is different from what is typically observed in older patients who have a poorer prognosis. Further cases are needed to investigate the prognostic impact of the leukemic phase of FL in younger patients., (© 2023 The Authors. Journal of Clinical Laboratory Analysis published by Wiley Periodicals LLC.)

Objectives: To study the diagnostic value of BCL2 rearrangement in follicle center lymphoma (FCL) presenting as primary skin lesions, evaluate its prevalence and the prognostic value in primary cutaneous FCL (PCFCL), and assess prognostic factors in PCFCL. Methods: Fifty-three patients with a cutaneous presentation of FCL without a history of nodal lymphoma were selected retrospectively. Clinical and histologic data were collected together with staging and follow-up data. A fluorescence in situ hybridization (FISH) test for BCL2 split probes was performed on skin biopsy specimens. Results: Initial staging procedures identified 47 PCFCLs and six cases of secondary skin involvement of FCL (SSIFCL). FISH detected seven cases carrying a BCL2 rearrangement: four (8.5%) of 47 PCFCLs and three (50%) of six SSIFCLs. These seven cases coexpressed BCL2 and CD10. In PCFCL, cutaneous relapse rate was 42.6%. A small/medium centrocytic cell population was associated with a higher probability of skin relapse in univariate (P = .008) and multivariate ( P = .028) analysis, and BCL2 rearrangement detection was associated with secondary extracutaneous spreading (P = .05). Conclusions: We observed that BCL2 rearrangement in PCFCL is rare, associated with initial positivity of staging (diagnostic value) or with secondary extracutaneous spreading (prognostic value). In selected cases with BCL2-CD10 coexpression, FISH testing could detect patients with poor outcome and require closer monitoring. [ABSTRACT FROM AUTHOR]

Kanagal-Shamanna R, Medeiros L J, Lu G, Wang S A, Manning J T, Lin P, Penn G M, Young K H, You M J, Vega F, Bassett R & Miranda R N (2012) Histopathology 61, 945-954 High-grade B cell lymphoma, unclassifiable, with blastoid features: an unusual morphological subgroup associated frequently with BCL2 and/or MYC gene rearrangements and a poor prognosis Aims: A subset of B cell lymphomas with blastoid features do not fit either as B lymphoblastic lymphoma/leukaemia or blastoid mantle cell lymphoma. Their classification is challenging, even with complete clinicopathological and genetic information. At a haematopathology workshop, experts had suggested the term 'high-grade B cell lymphoma, unclassifiable, with blastoid features', and recommended further studies. Methods and results: We describe the clinicopathological, immunophenotypic and cytogenetic findings of 24 high-grade B cell lymphomas, unclassifiable, with blastoid features. Fifteen patients presented de novo and seven patients had a history of lymphoma. Twenty patients (83%) presented with nodal disease. All tumours expressed pan-B cell antigens and 17 (89%) of 19 tumours assessed had a germinal centre B cell immunophenotype. Ten (63%) of 16 tumours assessed by fluorescence in-situ hybridization (FISH) had MYC rearrangement, 13 of 18 (72%) carried IGH- BCL2 and nine of 15 (60%) had both (double-hit lymphoma). The median overall survival was 1.1 years. Using 2008 World Health Organization criteria, 15 cases were classified as B cell lymphoma, unclassifiable, with features intermediate between diffuse large B cell lymphoma (DLBCL) and Burkitt lymphoma, and nine as DLBCL, small centroblastic variant. Conclusion: High-grade B cell lymphomas, unclassifiable, with blastoid features are clinically aggressive with poor survival. Most neoplasms have a germinal centre B cell phenotype. MYC rearrangements and IGH-BCL2 are common, and ∼60% are double-hit lymphomas. [ABSTRACT FROM AUTHOR]

MYC rearrangement is a relatively rare genetic abnormality in follicular lymphoma (FL). In this study, we evaluated the relative frequency of MYC rearrangement in 522 cases of FL and studied their clinicopathologic, cytogenetic, and molecular characteristics. Fluorescence in situ hybridization studies for MYC (break-apart probe), MYC/IGH, IGH/BCL2, and BCL6 rearrangements were performed on tissue microarrays. Immunohistochemical stains for CD10, BCL2, BCL6, and MYC were performed and scored on MYC-rearranged cases. On 4 FL cases, a custom targeted panel of 356 genes was used for mutation analysis. Ten cases (1.9%) were positive for MYC rearrangement. Histologically, 6 of 10 cases were grade 1-2, and 4 cases were grade 3A. By immunohistochemistry, 9 of 9 tested cases were CD10+, all cases were BCL6+, and 9/10 cases were BCL2+. MYC protein staining was low in all cases tested. IGH/BCL2 rearrangement was detected in 5 of 9 cases, whereas BCL6 rearrangement was detected in 3 of 7 tested cases and 4 of 10 cases showed MYC/IGH rearrangement. The most commonly detected mutations in the MYC-positive cases included HLA-B, TNFRSF14, and KMT2D. MYC and/or B2M abnormalities were detected in 2 cases. In conclusion, MYC rearrangement is uncommon in FL and these cases do not appear to have specific histologic characteristics. Molecular analysis showed abnormalities in genes associated with transformation, namely MYC and B2M. Larger studies are needed to evaluate if MYC-rearrangement in FL has prognostic significance., (Copyright © 2021 Elsevier Inc. All rights reserved.)