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Objectives The 2021 Society for Hematopathology and European Association for Haematopathology Workshop addressed the molecular and cytogenetic underpinnings of transformation and transdifferentiation in lymphoid neoplasms. Methods Session 4, “Transformations of Follicular Lymphoma,” and session 5, “Transformations of Other B-Cell Lymphomas,” included 45 cases. Gene alteration analysis and expression profiling were performed on cases with submitted formalin-fixed, paraffin embedded tissue. Results The findings from session 4 suggest that “diffuse large B-cell lymphoma/high-grade B-cell lymphoma with rearrangements of MYC and BCL2” is a distinct category arising from the constraints of a preexisting BCL2 translocation. TdT expression in aggressive B-cell lymphomas is associated with MYC rearrangements, immunophenotypic immaturity, and a dismal prognosis but must be differentiated from lymphoblastic ­lymphoma. Cases in session 5 illustrated unusual morphologic and immunophenotypic patterns of transformation. Additionally, the findings support the role of cytogenetic abnormalities—specifically, MYC and NOTCH1 rearrangements—as well as single gene alterations, including TP53, in transformation. Conclusions Together, these unique cases and their accompanying molecular and cytogenetic data suggest potential mechanisms for and unusual patterns of transformation in B-cell lymphomas and indicate numerous opportunities for further study.

Objectives To summarize the conclusions of the 2021 Society for Hematopathology/European Association for Haematopathology workshop regarding transformations of marginal zone lymphoma (MZL) and lymphoplasmacytic lymphoma (LPL). Methods Nineteen cases were submitted to this portion of the workshop. Additional studies were performed in cases with sufficient material. Results Cases included splenic MZL (n = 4), splenic diffuse red pulp small B-cell lymphoma (n = 2), nodal MZL (n = 4), extranodal MZL (n = 1), and LPL (n = 8). The most common transformation was to diffuse large B-cell lymphoma (DLBCL), but others included classic Hodgkin lymphoma, high-grade B-cell lymphomas with MYC and BCL6 rearrangements, plasmablastic lymphoma, and plasma cell leukemia. Two splenic MZLs with transformation to DLBCL contained t(14;19)(q32;q13.3) IGH::BCL3 rearrangements in both samples. Paired sequencing studies in 5 MZLs with transformation to clonally related DLBCL identified a variety of mutations and gene fusions at the time of transformation, including CARD11, IGH::MYC, NOTCH2, P2RY8, TBLX1X1, and IGH::CD274. Conclusions Marginal zone lymphoma and LPL may undergo a variety of transformation events, most commonly to DLBCL, which is usually, although not always, directly clonally related to the underlying low-grade lymphoma. Multiparameter analysis including broad-based sequencing studies can assist in the diagnosis and classification of these uncommon cases.

Objectives Session 2 of the 2021 Society for Hematopathology and European Association for Haematopathology Workshop collected examples of lineage infidelity and transdifferentiation in B-lineage neoplasms, including after targeted therapy. Methods Twenty cases were submitted. Whole-exome sequencing and genome-wide RNA expression analysis were available on a limited subsample. Results A diagnosis of B-cell acute lymphoblastic leukemia (B-ALL) was rendered on at least 1 biopsy from 13 patients. There was 1 case of acute myeloid leukemia (AML); the remaining 6 cases were mature B-cell neoplasms. Targeted therapy was administered in 7 cases of B-ALL and 4 cases of mature B-cell neoplasms. Six cases of B-ALL underwent lineage switch to AML or mixed-phenotype acute leukemia at relapse, 5 of which had rearranged KMT2A. Changes in maturational state without lineage switch were observed in 2 cases. Examples of de novo aberrant T-cell antigen expression (n = 2) were seen among the mature B-cell lymphoma cohort, and their presence correlated with alterations in tumor cell gene expression patterns. Conclusions This cohort of cases enabled us to illustrate, discuss, and review current concepts of lineage switch and aberrant antigen expression in a variety of B-cell neoplasms and draw attention to the role targeted therapies may have in predisposing neoplasms to transdifferentiation as well as other, less expected changes in maturational status.

Objectives To summarize cases submitted to the 2021 Society for Hematopathology/European Association for Haematopathology Workshop under the categories of progression of Hodgkin lymphoma, plasmablastic myeloma, and plasma cell myeloma. Methods The workshop panel reviewed 20 cases covered in this session. In addition, whole-exome sequencing (WES) and whole-genome RNA expression analysis were performed on 10 submitted cases, including 6 Hodgkin lymphoma and 4 plasma neoplasm cases. Results The cases of Hodgkin lymphoma included transformed cases to or from various types of B-cell lymphoma with 1 exception, which had T-cell differentiation. The cases of plasma cell neoplasms included cases with plasmablastic progression, progression to plasma cell leukemia, and secondary B-lymphoblastic leukemia. Gene variants identified by WES included some known to be recurrent in Hodgkin lymphoma and plasma cell neoplasm. All submitted Hodgkin lymphoma samples showed 1 or more of these mutations: SOCS1, FGFR2, KMT2D, RIT1, SPEN, STAT6, TET2, TNFAIP3, and ZNF217. Conclusions Better molecular characterization of both of these neoplasms and mechanisms of progression will help us to better understand mechanisms of progression and perhaps develop better prognostic models, as well as identifying novel therapeutic targets.

Objectives Session 3 of the 2021 Workshop of the Society for Hematopathology/European Association for Haematopathology examined progression and transformation of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) and B-cell prolymphocytic leukemia (B-PLL). Methods Thirty-one cases were reviewed by the panel. Additional studies such as immunohistochemistry and molecular genetic testing, including whole-exome sequencing and expression profiling, were performed in select cases. Results Session 3 included 27 CLL/SLL cases and miscellaneous associated proliferations, 3 cases of B-PLL, and 1 case of small B-cell lymphoma. The criteria for ­accelerated CLL/SLL are established for lymph nodes, but extranodal disease can be diagnostically challenging. Richter transformation (RT) is a broad term and includes true transformation from original CLL/SLL clone(s) and clonally unrelated neoplasms. The morphologic, immunophenotypic, and genetic spectrum is diverse with classical and highly unusual examples. T-cell proliferations can also be encountered in CLL/SLL. B-cell prolymphocytic leukemia is a rare, diagnostically challenging disease due to its overlaps with other lymphoid neoplasms. Conclusions The workshop highlighted complexity of progression and transformation in CLL/SLL and B-PLL, as well as diagnostic caveats accompanying heterogeneous presentations of RT and other manifestations of disease progression. Molecular genetic studies are pivotal for diagnosis and determination of clonal relationship, and to predict response to treatment and identify resistance to targeted therapy.

Objectives To report findings from the 2021 Society for Hematopathology/European Association for Haematopathology Workshop within the category of B-cell lineage neoplasms’ transdifferentiation into histiocytic/dendritic cell neoplasms (HDCNs). Methods The workshop panel reviewed 29 cases, assigned consensus diagnoses, and summarized findings. Results The specific diagnoses of transdifferentiated HDCN tumors were histiocytic sarcoma (16); Langerhans cell histiocytosis/sarcoma (5); indeterminate DC tumor (1); and HDCN, unclassifiable (1). Approximately one-third of the patients reviewed had follicular lymphoma; lymphoblastic leukemia/lymphoma; or another B-cell lymphoma, most commonly chronic lymphocytic leukemia/small lymphocytic lymphoma. There was a 3:1 preponderance toward women, median patient age was 60 years, and the median interval between the initial diagnosis of B-cell lineage neoplasm and HDCN was 4 to 5 years. The submitted cases have demonstrated substantial heterogeneity as well as overlapping immunophenotypic and other features. Comprehensive genomic DNA sequencing revealed alterations enriched in the MAPK pathway. Based on shared and distinct alterations seen in HDCNs and the preceding lymphomas, both linear and divergent clonal evolutionary pathways were inferred. Furthermore, RNA sequencing performed in a subset of cases yielded new insights into markers that could be useful for more precise cell lineage identification. The panel has thus proposed an updated algorithm for HDCN lineage assignment. The outcome of transdifferentiated HDCNs was poor, but the MAPK signaling pathway emerges as a potentially attractive therapeutic target. Conclusions Transdifferentiated HDCNs demonstrate heterogeneity and pose diagnostic challenges with regard to exact classification, but the in-depth characterization of the submitted cases have added to our understanding of the secondary HDCNs transdifferentiated from B-cell lymphoma/leukemia. Continuous efforts focusing on deciphering the specific cell lineage and differentiation state of these tumors will be critical for their accurate classification. Comprehensive molecular characterization of HDCNs may be informative in this regard. With the list of novel pharmacologic inhibitors of the MAPK pathway continuing to expand, improved outcomes for HDCN can be expected.

We investigated the clinicopathologic features of 5 follicular lymphomas (FLs) that transformed (tFL) morphologically to diffuse large B-cell lymphomas (DLBCLs) and had a primary mediastinal large B-cell lymphoma (PMBL)–like gene expression profile (tFL-PMBLsig-pos). None of the tFL-PMBLsig-pos cases arose in the mediastinum, all cases tested had a germinal center B-cell phenotype, 20% were CD30+, 60% CD23+, 80% MAL+, 20% CD200+, and 0% CD273/PDL2+. Whole-exome sequencing detected alterations in genes associated with both FL/DLBCL (CREBBP, KMT2C, KMT2D, ARID1A, HIST1 members, and TNFRSF14) and PMBL (JAK-STAT pathway genes, B2M, and CD58). Copy number (CN) analysis detected gains/amplification of REL and STAT6 in 60%, gains of SOCS1 in 40%, and gains of chromosome 16, including IL4R, in 40% of the cases. CN gains/amplification of BCL6 and MYC and loss of TNFRSF14 and TNFAIP3 were identified in 20% of the cases. Three of 5 cases lacked a BCL2 rearrangement. Despite having some features that are less common in DLBCL (MAL and CD23 expression and JAK-STAT activation), these tFL-PMBLsig-pos cases lack the most characteristic CN alteration seen in PMBL (9p24.1 gain/amplification). This cohort expands the biologic heterogeneity of tFL, illustrating a subset with gene expression and some genetic features reminiscent of PMBL, with potential treatment implications that include the use of novel targeted therapies.

Abstract Plasma cell neoplasms including multiple myeloma (MM) and related terminally differentiated B-cell neoplasms are characterized by secretion of monoclonal immunoglobulin and stepwise development from a preneoplastic clonal B and/or plasma cell proliferation called monoclonal gammopathy of undetermined significance (MGUS). Diagnosis of these disorders requires integration of clinical, laboratory, and morphological features. While their classification mostly remains unchanged compared to the revised 2016 WHO classification and the 2014 International Myeloma Working Group consensus, some changes in criteria and terminology were proposed in the 2022 International Consensus Classification (ICC) of mature lymphoid neoplasms. MGUS of IgM type is now divided into IgM MGUS of plasma cell type, precursor to the rare IgM MM and characterized by MM-type cytogenetics, lack of clonal B-cells and absence of MYD88 mutation, and IgM MGUS, NOS including the remaining cases. Primary cold agglutinin disease is recognized as a new entity. MM is now formally subdivided into cytogenetic groups, recognizing the importance of genetics for clinical features and prognosis. MM with recurrent genetic abnormalities includes MM with CCND family translocations, MM with MAF family translocations, MM with NSD2 translocation, and MM with hyperdiploidy, with the remaining cases classified as MM, NOS. For diagnosis of localized plasma cell tumors, solitary plasmacytoma of bone, and primary extraosseous plasmacytoma, the importance of excluding minimal bone marrow infiltration by flow cytometry is emphasized. Primary systemic amyloidosis is renamed immunoglobulin light chain amyloidosis (AL), and a localized AL amyloidosis is recognized as a distinct entity. This review summarizes the updates on plasma cell neoplasms and related entities proposed in the 2022 ICC. Key points • Lymphoplasmacytic lymphoma can be diagnosed with lymphoplasmacytic aggregates in trephine biopsies . • IgM MGUS is subdivided into a plasma cell type and a not otherwise specified (NOS) type. • Primary cold agglutinin disease is recognized as a new entity. • The term “multiple myeloma” replaces the term “plasma cell myeloma” used in the 2016 WHO classification. • Multiple myeloma is subdivided into 4 mutually exclusive cytogenetic groups and MM NOS. • Minimal bone marrow infiltration detected by flow cytometry is of major prognostic importance for solitary plasmacytoma of bone and to a lesser extent for primary extraosseous plasmacytoma. • Localized IG light chain amyloidosis is recognized as a separate entity, distinct from systemic immunoglobulin light chain (AL) amyloidosis.

Follicular lymphoma (FL) and marginal zone lymphoma (MZL) are indolent mature B-cell neoplasms with variable clinical presentation and distinct histopathologic features. Recent advances in the biology and molecular characteristics of these lymphomas have further expanded our understanding of the heterogeneous nature of these lymphomas, with increasing recognition of specific disease entities within the broader categories of FL and MZL. Here, we discuss the conclusions of the 2022 International Consensus Classification of Mature Lymphoid Neoplasms (2022 ICC) dealing with FL, and review differences with the proposed WHO 5th Edition classification. We review issues related to grading and alternative forms of FL especially those lacking the genetic hallmark of FL, the t(14;18) chromosomal alteration. Among them, t(14;18)-negative CD23+ follicle center lymphoma has been proposed by the 2022 ICC as a provisional entity. Other follicle center–derived lymphomas such as pediatric-type follicular lymphoma, testicular follicular lymphoma, primary cutaneous follicle center lymphoma, and large B-cell lymphoma with IRF4 rearrangement are considered distinct entities separate from conventional FL. Importantly, large B-cell lymphoma with IRF4 rearrangement introduced as a provisional entity in the WHO 2017 is upgraded to a definite entity in the 2022 ICC. We also discuss diagnostic strategies for recognition of MZLs including splenic MZL, extranodal MZL (MALT lymphoma), and primary nodal MZL. The importance of molecular studies in the distinction among marginal zone lymphoma subtypes is emphasized, as well as their value in the differential diagnosis with other B-cell lymphomas.

Objectives Sessions 8 and 9 of the 2021 Society for Hematopathology and the European Association for Haematopathology Workshop aimed to collect examples of transdifferentiation, lineage infidelity, progression, and transformation in precursor and mature T/natural killer (NK)–cell neoplasms. Methods Twenty-eight cases were submitted and analyzed, with whole-exome sequencing and genome-wide RNA expression analysis performed in a subset of the cases. Results In session 8, 7 T-lymphoblastic lymphoma/leukemia cases were received that showed transdifferentiation to clonally related mature myeloid hematopoietic neoplasms, including 6 histiocytic/dendritic cell lineage neoplasms and a mast cell sarcoma. Session 9 included 21 mature T-cell neoplasms that were grouped into 3 themes. The first one addressed phenotypic infidelity in mature T-cell lymphomas (TCLs) and included 8 TCLs expressing aberrant antigens, mimicking classic Hodgkin and non-Hodgkin B-cell lymphomas. The second theme addressed disease progression in TCL and included 5 cutaneous T-cell lymphoproliferative disorders and 2 T-cell large granular lymphocyte proliferations with subsequent progression to systemic TCL. The third theme included 6 patients with TCL with T-follicular helper phenotype, mainly angioimmunoblastic T-cell lymphoma, with concurrent/subsequent clonal hematopoiesis or myeloid neoplasms and/or subsequent/concomitant diffuse large B-cell lymphoma. Conclusions This cohort of cases allowed us to illustrate, discuss, and review current concepts of transdifferentiation, aberrant antigen expression, and progression in various T/NK-cell neoplasms.

A subset of patients with IgM monoclonal gammopathy of undetermined significance (MGUS) develop IgM-related disorders (IgM-RD) including peripheral neuropathy, cryoglobulinemia and/or cold agglutinin disease (CAD). We examined the clinical and bone marrow pathologic findings in 191 IgM MGUS patients (2016 WHO criteria). Clonal plasma cells were identified in 41/171 (24%) cases by immunohistochemistry (IHC) and clonal B-cells in 43/157 (27%). IgMRD was identified in 82 (43%) cases, including peripheral neuropathy (n=67, 35%), cryoglobulinemia (n=21, 11%), and CAD (n=10, 5%). Cases of CAD showed distinctive features including lack of MYD88 mutations (p=0.048), supporting the concept of primary CAD as a distinct clinicopathologic disorder. Following exclusion of CAD, comparison of the remaining cases with (n=72) or without (n=109) IgM-RD showed IgM-RD to be more frequent in men than women (p=0.02) and to be more highly associated with MYD88 L265P (p=0.011). Cases with and without IgM-RD otherwise showed similar features including serum IgM concentrations, presence of lymphoid aggregates, clonal B-cells by flow cytometry or clonal plasma cells by IHC. No differences were observed in overall survival between cases with and without IgM-RD. No cases in this series met criteria for plasma cell type IgM MGUS as defined in the 2022 International Consensus Classification of lymphoid neoplasms. These results show IgM-RD to be common in patients with IgM MGUS. While CAD shows distinctive features, the remaining cases of IgM-RD largely show pathologic findings similar to IgM MGUS without IgM-RD.

Constitutive activation of NF-κB is a hallmark of the activated B cell–like (ABC) subtype of diffuse large B-cell lymphoma (DLBCL), owing to upstream signals from the B-cell receptor (BCR) and MYD88 pathways. The linear polyubiquitin chain assembly complex (LUBAC) attaches linear polyubiquitin chains to IκB kinase-γ, a necessary event in some pathways that engage NF-κB. Two germline polymorphisms affecting the LUBAC subunit RNF31 are rare among healthy individuals (∼1%) but enriched in ABC DLBCL (7.8%). These polymorphisms alter RNF31 α-helices that mediate binding to the LUBAC subunit RBCK1, thereby increasing RNF31–RBCK1 association, LUBAC enzymatic activity, and NF-κB engagement. In the BCR pathway, LUBAC associates with the CARD11–MALT1–BCL10 adapter complex and is required for ABC DLBCL viability. A stapled RNF31 α-helical peptide based on the ABC DLBCL–associated Q622L polymorphism inhibited RNF31–RBCK1 binding, decreased NF-κB activation, and killed ABC DLBCL cells, credentialing this protein–protein interface as a therapeutic target.Significance: We provide genetic, biochemical, and functional evidence that the LUBAC ubiquitin ligase is a therapeutic target in ABC DLBCL, the DLBCL subtype that is most refractory to current therapy. More generally, our findings highlight the role of rare germline-encoded protein variants in cancer pathogenesis. Cancer Discov; 4(4); 480–93. ©2014 AACR.See related commentary by Grumati and Dikic, p. 394This article is highlighted in the In This Issue feature, p. 377

PDF file 42K, Co-occurrence of RNF31 SNPs with other genetic lesions in ABC DLBCL cases

Supplementary Table 1 PDF file 53K, Enrichment of two rare SNPs among ABC DLBCL tumors

PDF file 124K, Involvement of LUBAC in CBM complex mediated NF-kappaB activation, related to main figure 3

PDF file 149K, RNF31 peptides internalized equivalently in ABC DLBCL cells

PDF file 73K, Constitutive linear ubiquitination of NEMO in ABC comparing to GCB DLBCL cells

PDF file 132K, Specificity of RNF31 stapled peptides in ABC DLBCL

PDF file 283K, RNF31 DNA sequence electropherograms for the region corresponding to the single nucleotide polymorphisms (SNPs)

Table S1. Patient Charactertistics and their mi-EP platform type

Purpose:Peripheral T-cell lymphoma (PTCL) is a heterogeneous group of non–Hodgkin lymphomas with aggressive clinical behavior. We performed comprehensive miRNA profiling in PTCLs and corresponding normal CD4+ Th1/2 and TFH-like polarized subsets to elucidate the role of miRNAs in T-cell lymphomagenesis.Experimental Design:We used nCounter (NanoString Inc) for miRNA profiling and validated using Taqman qRT-PCR (Applied Biosystems, Inc). Normal CD4+ T cells were polarized into effector Th subsets using signature cytokines, and miRNA significance was revealed using functional experiments.Results:Effector Th subsets showed distinct miRNA expression with corresponding transcription factor expression (e.g., BCL6/miR-19b, -106, -30d, -26b, in IL21-polarized; GATA3/miR-155, miR-337 in Th2-polarized; and TBX21/miR-181a, -331-3p in Th1-polarized cells). Integration of miRNA signatures suggested activation of TCR and PI3K signaling in IL21-polarized cells, ERK signaling in Th1-polarized cells, and AKT–mTOR signaling in Th2-polarized cells, validated at protein level. In neoplastic counterparts, distinctive miRNAs were identified and confirmed in an independent cohort. Integrative miRNA–mRNA analysis identified a decrease in target transcript abundance leading to deregulation of sphingolipid and Wnt signaling and epigenetic dysregulation in angioimmunoblastic T-cell lymphoma (AITL), while ERK, MAPK, and cell cycle were identified in PTCL subsets, and decreased target transcript abundance was validated in an independent cohort. Elevated expression of miRNAs (miR-126-3p, miR-145-5p) in AITL was associated with poor clinical outcome. In silico and experimental validation suggest two targets (miR-126→ SIPR2 and miR-145 → ROCK1) resulting in reduced RhoA-GTPase activity and T–B-cell interaction.Conclusions:Unique miRNAs and deregulated oncogenic pathways are associated with PTCL subtypes. Upregulated miRNA-126-3p and miR-145-5p expression regulate RhoA-GTPase and inhibit T-cell migration, crucial for AITL pathobiology.

Figure S6: Overall Survival in PTCL by miRNA expression. Kaplan-Meier curve representing overall survival of PTCL-NOS cases (n=24) by higher vs lower expression of miR-29c (A) and miR-106 (B) expression. (C) Correlation of n-Counter values between miR-126 and miR-145 expression (r=0.1)

Table S2: List of Antibodies used for the Western Blot Table S3: List of flow cytometry Antibodies used for the expression of different markers Table S4: List of genes and their Forward and Reverse Sequence for the evaluation of mRNA expression by performing Real time RT PCR Table S5: Mature Sequence of miR-126-3p and miR-145-5p taqman Probe used for Taqman base Real time qPCR assay

CCR Translation for This Article from BCL2 Predicts Survival in Germinal Center B-cell–like Diffuse Large B-cell Lymphoma Treated with CHOP-like Therapy and Rituximab

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Purpose: We have previously shown the prognostic significance of BCL2 expression in the activated B-cell–like diffuse large B-cell lymphoma (ABC-DLBCL) patients treated with cyclophosphamide-Adriamycin-vincristine-prednisone (CHOP) or CHOP-like therapy. However, after the inclusion of rituximab (R) in the CHOP regimen, several conflicting observations about the prognostic value of BCL2 expression have been reported.Experimental Design: We evaluated the R-CHOP cohort of 221 DLBCL cases with gene expression profiling data. BCL2 protein (n = 169), mRNA (n = 221) expression, and t(14;18) (n = 144) were correlated with clinical outcome. The CHOP cohort (n = 181) was used for comparative analysis.Results: BCL2 protein expression has significant impact on overall survival (OS) and event-free survival (EFS) in DLBCL (OS, P = 0.009; EFS, P = 0.001) and GCB-DLBCL (OS, P = 0.03; EFS, P = 0.002) but not in ABC-DLBCL in the R-CHOP cohort. The survival differences for EFS in GCB-DLBCL were still observed in multivariate analysis. At the mRNA level, this correlation was observed in EFS in DLBCL (P = 0.006), but only a trend was observed in GCB-DLBCL (P = 0.09). The t(14;18) was detected in 34% of GCB-DLBCL but was not associated with significant differences in survival. Gene enrichment analysis identified significant enrichment of the DLBCL “stromal-1” signatures and hypoxia-inducible factor 1 (HIF1-α) signature in BCL2(−)GCB-DLBCL, whereas TFH cell signatures were enriched in BCL2(+)GCB-DLBCL.Conclusion: The prognostic significance of BCL2 has changed after inclusion of rituximab in the treatment protocol and is observed in the GCB-DLBCL rather than the ABC-DLBCL. Although rituximab has benefited patients in both DLBCL subgroups, the BCL2(+)GCB-DLBCL seems to receive less benefit from this treatment and may require other novel therapeutic intervention. Clin Cancer Res; 17(24); 7785–95. ©2011 AACR.

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The Molecular Pathology Section, Cleveland Clinic (Cleveland, OH), has undergone enhancement of its testing portfolio and processes. An Excel 2013- and paper-based data-management system was replaced with a commercially available laboratory information-management system (LIMS) software application, a separate bioinformatics platform, customized test-interpretation applications, a dedicated sample-accessioning service, and a results-releasing software application. The customized LIMS solution manages complex workflows, large-scale data packets, and process automation. A customized approach was required because, in a survey of commercially available off-the-shelf software products, none met the diverse and complex needs of this molecular diagnostics service. The project utilized the expertise of clinical laboratorians, pathologists, genetics counselors, bioinformaticians, and systems analysts in partnering with software-engineering consultants to design and implement a solution. Concurrently, Agile software-building best practices were formulated, which may be emulated for scalable and cost-effective laboratory-authored software.

Black communities have been disproportionately impacted by the syndemic of COVID-19 and structural racism. Place-based initiatives (PBIs) are well-positioned to respond to this syndemic. This study sought to highlight disparities in access to social determinants of health (SDH) between two racially segregated communities, assess residents' needs and measure resource accessibility in one predominantly Black community, and describe the PBI's response. We measured racial disparities in access to SDH before COVID-19 using an SDH Index. We assessed participants' needs using a needs assessment and documented resource availability. A Geographic Information System (GIS) was used to measure resource accessibility. Results show inequities in access to SDH between the two communities before COVID-19. Following the onset of COVID-19, unemployment and food insecurity were higher in the predominantly Black community relative to the US population. Available resources did not always align with participants' needs and were less accessible for residents without private transportation. The PBI's response to the syndemic spanned SDH sectors. Inequitable access to SDH may be produced by structural racism and exacerbated by COVID-19. PBIs are well-equipped to employ a contextually informed, data-driven, cross-sector response to the syndemic.

Objectives CUX1 mutations have been reported in myeloid neoplasms. We aimed to characterize the mutational landscape, clonal architecture, and clinical characteristics of myeloid disorders with CUX1 variants. Methods We reviewed data from a targeted 62-gene panel with CUX1 variants. Variants were classified as of strong or potential clinical significance (tier I/tier II) or of unknown significance (VUS). Results CUX1 variants were identified in 169 cases. The 49 tier I/tier II variants were found in older patients (mean age, 71 vs 60 years old) and predominantly inactivating alterations, while the 120 VUS cases were missense mutations. Monosomy 7/deletion 7q was more common in tier I/tier II cases. Co-mutations were detected in 96% of tier I/tier II cases (average, 3.7/case) but in only 61% of VUS cases (average, 1.5/case). Tier I/tier II CUX1 variants tend to be subclonal to co-mutations (ASXL1, SF3B1, SRSF2, TET2). Among myeloid disorders, tier I/tier II cases were more frequently diagnosed with myelodysplastic syndromes and had a higher number of bone marrow dysplastic lineages. Conclusions CUX1 mutations are seen with adverse prognostic features and could be a late clonal evolutional event of myeloid disorders. The differences between CUX1 tier I/tier II and VUS underscore the importance of accurate variant classification in reporting of multigene panels.

The present study examined the effects of data-guided innovations on students' social-emotional (SE) development within prekindergarten settings. Specifically, this study examined the effects of a pilot effort that sought to improve instructional quality through the use of structured classroom observations by coaches to help support teacher implementation of curricula and evidence-based practices. In addition, teachers used formative assessments of students' SE functioning to guide and individualize their instruction. To examine the effects of the multicomponent intervention, this study compared the SE functioning of students across three conditions: (1) students whose teachers received no data-guided innovations; (2) students whose teachers received SE formative assessments; and (3) students whose teachers received both SE formative assessments and performance-based feedback using structured classroom observations. Students whose teachers received both SE formative assessments and performance-based feedback using structured classroom observations evidenced significantly greater SE competencies than those in the control group. Additionally, students whose teachers just received SE formative assessments evidenced greater SE competencies than those in the control group, however, the differences were not significant. Results indicate the potential value of these data-guided innovations for improving prekindergarten student outcomes such as SE development and point to the next steps for future research.

Purpose: Peripheral T-cell lymphoma (PTCL) is a heterogeneous group of non–Hodgkin lymphomas with aggressive clinical behavior. We performed comprehensive miRNA profiling in PTCLs and corresponding normal CD4+ Th1/2 and TFH-like polarized subsets to elucidate the role of miRNAs in T-cell lymphomagenesis. Experimental Design: We used nCounter (NanoString Inc) for miRNA profiling and validated using Taqman qRT-PCR (Applied Biosystems, Inc). Normal CD4+ T cells were polarized into effector Th subsets using signature cytokines, and miRNA significance was revealed using functional experiments. Results: Effector Th subsets showed distinct miRNA expression with corresponding transcription factor expression (e.g., BCL6/miR-19b, -106, -30d, -26b, in IL21-polarized; GATA3/miR-155, miR-337 in Th2-polarized; and TBX21/miR-181a, -331-3p in Th1-polarized cells). Integration of miRNA signatures suggested activation of TCR and PI3K signaling in IL21-polarized cells, ERK signaling in Th1-polarized cells, and AKT–mTOR signaling in Th2-polarized cells, validated at protein level. In neoplastic counterparts, distinctive miRNAs were identified and confirmed in an independent cohort. Integrative miRNA–mRNA analysis identified a decrease in target transcript abundance leading to deregulation of sphingolipid and Wnt signaling and epigenetic dysregulation in angioimmunoblastic T-cell lymphoma (AITL), while ERK, MAPK, and cell cycle were identified in PTCL subsets, and decreased target transcript abundance was validated in an independent cohort. Elevated expression of miRNAs (miR-126-3p, miR-145-5p) in AITL was associated with poor clinical outcome. In silico and experimental validation suggest two targets (miR-126→ SIPR2 and miR-145 → ROCK1) resulting in reduced RhoA-GTPase activity and T–B-cell interaction. Conclusions: Unique miRNAs and deregulated oncogenic pathways are associated with PTCL subtypes. Upregulated miRNA-126-3p and miR-145-5p expression regulate RhoA-GTPase and inhibit T-cell migration, crucial for AITL pathobiology.

Background It has been proposed that primary cutaneous marginal zone lymphomas (PCMZL) include a MALT lymphoma-like IgM+ subset and a class-switched subset which is unlike most other MALT lymphomas. Whether expression of the MALT lymphoma-associated biomarkers IRTA1 and MNDA would support this concept and whether they might help explain why some patients have both subtypes is uncertain. Methods Twenty-five PCMZLs from 21 patients were stained for IRTA1 by in situ hybridization and for MNDA by immunohistochemistry. In two patients, PCR-based B-cell clonality studies were performed on biopsy specimens of metachronous lesions which expressed different heavy chains. All results were correlated with the histopathologic and clinical findings. Results Five of six IgM+ PCMZLs were IRTA1+ versus three of 18 evaluable class-switched cases (p=0.0069). Two of the class-switched IRTA1+ cases were in patients with clonally-related IRTA1+ IgM+ PCMZLs. IRTA1 positivity demonstrated a statistically significant correlation with several MALT lymphoma-associated histopathologic findings. In contrast, all PCMZL cases showed at least some MNDA expression with no differences between IgM+ and class-switched cases. Conclusions IRTA1 identifies MALT lymphoma-like PCMZLs that are largely but not exclusively IgM+. This supports the concept of two PCMZL subsets but suggests their distinction should not be based solely on their heavy chain expression. This article is protected by copyright. All rights reserved.

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.

ObjectivesTo define the clinicopathologic features of extranodal marginal zone lymphoma (EMZL) of the central nervous system (CNS), including cases arising in CNS parenchyma, which have been reported only rarely.MethodsTwelve cases of CNS EMZL were identified, including 5 based in CNS parenchyma and 7 nonparenchymal cases arising in dura or choroid plexus.ResultsHistologically, parenchymal cases were perivascular infiltrates without a dominant lymphoid mass, whereas nonparenchymal cases were masses of small lymphocytes. Plasma cells were a larger component of the infiltrate in parenchymal cases (median, 30%; range, 20%-50%) than nonparenchymal cases (median, 0%; range, 0%-5%; P < .001), and plasma cells were clonal by immunohistochemistry in 4 of 5 parenchymal vs 1 of 7 nonparenchymal cases (P = .07). Fluorescence in situ hybridization for MALT1 rearrangement was positive in 1 of 3 parenchymal and none of 3 nonparenchymal cases. Chromosomal microarray was abnormal in 5 of 7 cases (71%), with chromosome 6/6q alterations identified in 3 cases. No patients with parenchymal disease but all 6 (100%) with nonparenchymal disease achieved complete remission.ConclusionsThis case series, the first to include multiple parenchymal cases, clarifies the spectrum of clinical, pathologic, and genetic findings in CNS EMZL and suggests that parenchymal-based lesions may show less favorable prognosis than dural-based disease.

The last century and a half has seen first the recognition of lymphomas, and then the publication of one lymphoma classification after another often together with highly critical comments about preceding classifications or a welcome that was less than warm. The introduction of HUMAN PATHOLOGY in 1970 came just before one of the very acrimonious periods in lymphoma classification, as we were learning more about the normal immune system and with the proposed functional lymphoma classifications of Lukes/Collins and Kiel in 1974 relating the lymphomas to their normal B-cell or T-cell 'counterparts'. Those difficult times were followed by the regressive strictly morphologic NCI Working Formulation in 1982, with the REAL classification in 1994 putting us back on a rational path, once again grouping the lymphoid neoplasms first into those of B-cell and T- and putative NK-cell origin, and then using multiple parameters to define specific entities. Planning for the first modern WHO lymphoma classification began soon afterward, with concordance and collegiality leading to the 2001 WHO classification, which then evolved with publication of the 2008 and 2016 WHO classifications. While this review looks at these important past developments which have gotten us to where we are today, it also concentrates on where we are now, what has been learned since the most recent WHO classification and 'Blue Book' were published and on some of the unanswered questions that remain as we look to the future.

Establishing a diagnosis of nodular lymphocyte-predominant Hodgkin lymphoma (nLPHL) is often challenging as the differential diagnosis is broad, including classic Hodgkin lymphoma (cHL), progressive transformation of germinal centers (PTGC), and other lymphoproliferative disorders. In this study, we investigate the utility of a recently described ultrasensitive in situ hybridization assay for kappa and lambda immunoglobulin light chains in distinguishing nLPHL, cHL, and PTGC. A total of 72 cases were examined (21 nLPHL, 33 cHL, and 18 PTGC). In nLPHL, the large neoplastic cells were light chain restricted in 21/21 (100%) cases (16 kappa, 5 lambda). In contrast, Reed-Sternberg cells of cHL were negative for kappa and lambda in all cases (0/33, 0%; P0.001). In PTGC, polytypic B cells were noted in mantle zones and germinal centers in all cases, with 1 case (5%) also showing focal collections of light chain restricted large B cells. Background monotypic small B cells were identified in 3 cases, including 1 nLPHL and 2 cHL (1 of which arose in chronic lymphocytic leukemia). Ultrasensitive in situ hybridization for kappa and lambda is a useful addition to a standard immunophenotyping panel for the evaluation of suspected nLPHL.

Microglia, resident brain immune cells, are critical in orchestrating responses to central nervous system (CNS) injury. Many microglial functions, such as phagocytosis, motility and chemotaxis, are suggested to rely on chloride channels, including the volume-regulated anion channel (VRAC), but studies to date have relied on the use of pharmacological tools with limited specificity. VRAC has also been proposed as a drug target for acute CNS injury, and its role in microglial function is of considerable interest for developing CNS therapeutics. This study aimed to definitively confirm the contribution of VRAC in microglia function by using conditional LRRC8A-knockout mice, which lacked the essential VRAC subunit LRRC8A in microglia. We demonstrated that while VRAC contributed to cell volume regulation, it had no effect on phagocytic activity, cell migration or P2YR12-dependent chemotaxis. Moreover, loss of microglial VRAC did not affect microglial morphology or the extent of ischemic damage following stroke. We conclude that VRAC does not critically regulate microglial responses to brain injury and could be targetable in other CNS cell types (e.g., astrocytes) without impeding microglial function. Our results also demonstrate a role for VRAC in cell volume regulation but show that VRAC is not involved in several major cellular functions that it was previously thought to regulate, and point to other, alternative mechanisms of chloride transport in innate immunity.

Since the publication of the Revised European-American Classification of Lymphoid Neoplasms in 1994, subsequent updates of the classification of lymphoid neoplasms have been generated through iterative international efforts to achieve broad consensus among hematopathologists, geneticists, molecular scientists, and clinicians. Significant progress has recently been made in the characterization of malignancies of the immune system, with many new insights provided by genomic studies. They have led to this proposal. We have followed the same process that was successfully used for the third and fourth editions of the World Health Organization Classification of Hematologic Neoplasms. The definition, recommended studies, and criteria for the diagnosis of many entities have been extensively refined. Some categories considered provisional have now been upgraded to definite entities. Terminology for some diseases has been revised to adapt nomenclature to the current knowledge of their biology, but these modifications have been restricted to well-justified situations. Major findings from recent genomic studies have impacted the conceptual framework and diagnostic criteria for many disease entities. These changes will have an impact on optimal clinical management. The conclusions of this work are summarized in this report as the proposed International Consensus Classification of mature lymphoid, histiocytic, and dendritic cell tumors. ispartof: BLOOD vol:140 issue:11 pages:1229-1253 ispartof: location:United States status: published