Background: Sinonasal undifferentiated carcinoma (SNUC) is an extremely rare, high-grade, and aggressive tumor of the sinonasal tract. Due to the rarity of this malignancy, current treatment guidelines are based on small and often/mainly single-center retrospective datasets. In the absence of a universally accepted standard of care for SNUC, treatment approaches vary across countries and institutions, reflecting real-world clinical practice. The primary aim of this study was to describe real-world treatment and outcomes for patients with confirmed SNUC. Methods: This was an international, multi-center, retrospective, observational cohort study that pooled patients into the largest SNUC dataset to date. Fifteen centers were enrolled to contribute data, including seven from Europe, four from the United States, three from the United Kingdom, and one from Canada. In the absence of a universally accepted standard of care for SNUC, treatment approaches varied across countries and institutions, reflecting real-world clinical practice. Patients included were those with histologically confirmed SNUC who were treated between 1997 and 2021. Results: This study yielded 485 patients treated for SNUC. The median age at diagnosis was 55.6 years (IQR: 44.5-67.6), and 63.7% were male. Most cases presented at advanced stages, with 70.8% as T4a or T4b. Overall survival (OS) outcomes were available for 412 patients, with a median follow-up of 26.0 months. The 5- and 10-year OS were 47.2% (95% CI: 40.8-53.3%) and 39.6% (95% CI: 32.5-46.6%), respectively. Advanced age, dichotomized T-stage (T4a/b vs. T1-3), M-stage, and orbital involvement were significant poor prognostic factors on univariable analysis (p's < 0.01). On multivariable analysis, orbital involvement (HR: 2.73, 95% CI: 1.42-5.27, p = 0.003) and distance metastasis stage (HR: 3.00, 95% CI: 1.25-7.21, p = 0.014) were both independently associated with worse OS. Conclusions: This observational study presents the largest multi-center cohort analysis of SNUC to date, providing new insights into prognostic factors for a rare cancer treated at global centers of excellence. Orbital involvement and the presence of metastases are candidate independent risk factors associated with poorer OS.

Mediastinal grey zone lymphoma (MGZL) is a rare disease with overlapping features between classical Hodgkin lymphoma (CHL) and primary mediastinal large B-cell lymphoma (PMBL). The recent classifications limit the disease to mediastinal cases. Epstein-Barr virus (EBV) is negative in most instances. Predominant resemblance to CHL (MGZL-HL) or primary mediastinal B-cell lymphoma (MGZL-PMBL) can commonly be defined, although mixed features do occur. The morpho-phenotypic heterogeneity of MGZL has significantly affected diagnostic reproducibility also among experts and the proposed diagnostic criteria turned out less concrete than for other lymphomas. Seventy GZL cases were collected from 14 Italian centres and slides reviewed by expert haematopathologists: 17 samples were confirmed according to current classification criteria, the residual being reclassified, mostly as CHL and PMBL, which well reflects the diagnostic challenge. By applying six B-cell markers, MGZL-HL commonly expressed ≥4 B-antigens in ≥50% neoplastic cells at moderate-strong intensity; MGZL-PMBL expressed less B-cell markers than expected (average 3.4 per case, in ≥50% neoplastic cells) at variable intensity. Overall, morphology, number of positive B-cell markers, staining intensity and percentage of positive neoplastic cells are features that must be considered collectively, case by case, trying to adhere to the recent classification criteria, being aware that not all cases may easily be included.

Background:The retinoic-acid-receptor-related orphan receptor gamma t (RORγt) isoform is required for the development of lymphoid organs, T-helper 17 cells (Th17), and innate lymphoid cells (ILC3s). Recent data in mouse and human have revealed non-T, non-ILC3 cell populations with antigen presenting features that express RORγt. This study maps the presence of RORγt cells with dendritic cell (DC) features in human adult and fetal lymphoid tissues. Methods:By combining multicolor flow cytometry, RNAseq of peripheral blood cells, analysis of lymph node scRNAseq datasets, and microscopic analysis on human tissue sections and single-cell suspensions, this study maps the presence of RORγt cells with DC features in human tissues. Results:RORγt-DCs are found in human lymphoid organs, particularly in lymph nodes. Lymph node RORγt-DCs are located in the interfollicular area surrounding high endothelial venules and in the marginal sinuses. In terms of phenotype, RORγt-DCs are distinct from other nodal dendritic cells. They express PRDM16 and PIGR as well as transcripts supporting the antigen presentation machinery, while lacking stromal markers. A significant fraction of RORγt-DCs is proliferating, suggesting local self-renewal. Moreover, most of them lack autoimmune regulator (AIRE) expression. Comparison with mouse RORγt Thetis cells (TC) and Janus cells (JC) shows more similarity with group II TC than group I and III TC or JC, all of which are tolerogenic and express AIRE. Conclusion:Overall, this study identifies human lymph nodes as a relevant niche for RORγt-DCs and establishes tools for their microscopic mapping in human disease states.

The germinal center (GC) dark zone (DZ) and light zone represent distinct anatomical regions in lymphoid tissue where B cell proliferation, immunoglobulin diversification, and selection are coordinated. Diffuse large B cell lymphomas (DLBCLs) with DZ-like gene expression profiles exhibit poor outcomes, though the reasons are unclear and are not directly related to proliferation. Physiological DZs exhibit an exclusion of T cells, prompting exploration of whether T cell paucity contributes to DZ-like DLBCL. We used spatial transcriptomic approaches to achieve higher resolution of T cell spatial heterogeneity in the GC and to derive potential pathways that underlie T cell exclusion. We showed that T cell exclusion from the DZ was linked to DNA damage response (DDR) and chromatin compaction molecular features characterizing the spatial DZ signature, and that these programs were independent of activation-induced cytidine deaminase (AID) activity. As ATR is a key regulator of DDR, we tested its role in the T cell inhibitory DZ transcriptional imprint. ATR inhibition reversed not only the DZ transcriptional signature, but also DZ T cell exclusion in DZ-like DLBCL in vitro microfluidic models and in in vivo samples of murine lymphoid tissue. These findings highlight that ATR activity underpins a physiological scenario of immune silencing. ATR inhibition may reverse the immune-silent state and enhance T cell-based immunotherapy in aggressive lymphomas with GC DZ-like characteristics.

Human recombination-activating gene (RAG) deficiency can manifest with distinct clinical and immunological phenotypes. By applying a multiomics approach to a large group of RAG-mutated patients, we aimed at characterizing the immunopathology associated with each phenotype. Although defective T and B cell development is common to all phenotypes, patients with hypomorphic RAG variants can generate T and B cells with signatures of immune dysregulation and produce autoantibodies to a broad range of self-antigens, including type I interferons. T helper 2 (TH2) cell skewing and a prominent inflammatory signature characterize Omenn syndrome, whereas more hypomorphic forms of RAG deficiency are associated with a type 1 immune profile both in blood and tissues. We used cellular indexing of transcriptomes and epitopes by sequencing (CITE-seq) analysis to define the cell lineage-specific contribution to the immunopathology of the distinct RAG phenotypes. These insights may help improve the diagnosis and clinical management of the various forms of the disease.

Cytogenetic of COH-DHL1 and COH-THL1 HGBCL-DH-BCL2(-BCL6) cell line models (A-D); In vivo secondary Ighv gene rearrangements in BCR-less murine lambda-MYC lymphomas (E-J)

When two lymphomas occur concurrently or sequentially in a patient, it is a major question whether they derive from the same lymphocyte or hematopoietic precursor cell or developed independently. We studied four composite classic Hodgkin lymphomas (HL) and other mature B-cell lymphomas, and two composite mature B- and T-cell neoplasias by whole exome sequencing (WES). Analysis of their IGV genes revealed that three composite B-cell lymphomas originated from common germinal center-experienced B cells. WES identified shared somatic mutations in the lymphomas of these clonally related composite lymphomas, indicating their derivation from a common, pre-malignant precursor. Most mutations were restricted to one or the other of these lymphomas, likely explaining how distinct lymphomas developed from a common ancestral B cell. In the two B-cell/T-cell lymphoma cases, and a composite clonally unrelated HL/chronic lymphocytic leukemia, the lymphoma partners did not share any somatic mutations. In three cases, we identified potentially oncogenic variants also in cells serving as constitutional controls. These variants may have contributed to development of a composite lymphoma/leukemia. We provide additional evidence of frequent clonal relation in composite lymphomas, highlight the multistep transformation process of related lymphomas with a likely pre-malignant intermediate common precursor, and support the importance of constitutional variants in lymphomagenesis.

The B-cell receptor (BCR) is critical for mature B-cell lymphomas (BCL), serving as a therapeutic target. We show that high-grade BCLs with MYC and BCL2 rearrangements [HGBCL-double-hit (DH)-BCL2] predominantly exhibit immunoglobulin heavy (IGH) chain silencing, leading to BCR shutdown. IGH-silenced HGBCL-DH-BCL2 (IGHUND) tumors differ from IGH+ counterparts in germinal center (GC) zone programs, MYC expression, and immune infiltrate. Whereas IGH+ HGBCL-DH-BCL2 tumors favor IGM/IG-κ expression, IGHUND counterparts complete IGH isotype switching and IG-λ rearrangements. IGHUND lymphomas retain productive IGHV rearrangements and require IGH for optimal fitness. BCR silencing, caused by accelerated IGH turnover and reduced IGH expression, precedes HGBCL-DH-BCL2 onset, inducing RAG1/2-dependent IG light chain editing and facilitating t(8;22)/IGL::MYC translocations. IGHUND HGBCL-DH-BCL2 models exhibit reduced sensitivity to the CD79B-targeting antibody-drug conjugate polatuzumab vedotin. Collectively, HGBCL-DH-BCL2 commonly arises from isotype-switched t(14;18)+ GC B cells, which edit IG light chains, fueling intraclonal diversification, BCR extinction, and t(8;22) while maintaining IGH dependence, with clinical implications. SIGNIFICANCE:These findings link BCR silencing in IGH isotype-switched t(14;18)+ GC B cells to RAG1/2 expression, which triggers IG light chain editing and predisposes to IGL::MYC translocations, promoting HGBCL. In HGBCL with MYC and BCL2 rearrangements, BCR silencing protects from polatuzumab vedotin killing. See related commentary by Shevchenko and Hodson, p. 284.

Standardized treatment options are lacking for patients with unresectable or multifocal follicular dendritic cell sarcoma (FDCS) and disease-related mortality is as high as 20%. Applying whole-genome sequencing (WGS) in one case and whole-exome sequencing (WES) in additional twelve cases, this study adds information on the molecular landscape of FDCS, expanding knowledge on pathobiological mechanisms and identifying novel markers of potential theragnostic significance. Massive parallel sequencing showed high frequency of mutations on oncosuppressor genes, particularly in RB1, CARS and BRCA2 and unveiled alterations on homologous recombination DNA damage repair-related genes in 70% (9/13) of cases. This indicates that patients with high-stage FDCS may be eligible for poly ADP ribose polymerase inhibition protocols. Low tumor mutational burden was confirmed in this study despite common PDL1 expression in FDCS arguing on the efficacy of immune checkpoint inhibitors. CDKN2A deletion, detected by WGS and confirmed by fluorescence in situ hybridization in 41% of cases (9/22) indicates that impairment of cell cycle regulation may sustain oncogenesis in FDCS. Absence of mutations in the RAS/RAF/MAPK pathway and lack of clonal hematopoiesis-related mutations in FDCS sanction its differences from dendritic cell-derived neoplasms of hematopoietic derivation. WGS and WES in FDCS provides additional information on the molecular landscape of this rare tumor, proposing novel candidate genes for innovative therapeutical approaches to improve survival of patients with multifocal disease.

The B cell receptor (BCR) is essential for mature B cell lymphomas, serving as therapeutic target. Here, we show that high-grade B cell lymphomas with MYC and BCL2 rearrangements (HGBCL-DH- BCL2 ) predominantly exhibit immunoglobulin heavy (IGH) chain silencing, leading to BCR shutdown. HGBCL-DH- BCL2 with undetectable IGH (IGHUND) differ from IGH-expressing counterparts for germinal center-zone gene programs, MYC expression and T cell infiltration. While IGH+ HGBCL-DH- BCL2 prefer IGM/IG-Kappa expression, IGHUND counterparts have completed IGH class-switching, favoring IG-Lambda (IGL) light chains. IGHUND HGBCL-DH- BCL2 preserve IGHV gene integrity, overcoming antigen-driven selection. IGH silencing precedes onset and shapes evolution of HGBCL-DH- BCL2 from Follicular Lymphoma (FL) or FL/HGBCL-DH- BCL2 common precursor. In FL/HGBCL-DH- BCL2 pairs and HGBCL-DH- BCL2 models, BCR silencing promoted RAG1/2-dependent IG light chain editing, causing t(8;22)(q24;q11)/ IGL :: MYC . IGH silencing protected HGBCL-DH- BCL2 models from killing by CD79B-targeting Polatuzumab-Vedotin. Collectively, HGBCL-DH- BCL2 primarily originate from BCR-silenced isotype-switched t(14;18)/ IGH::BCL2 -positive (pre)FL cells acquiring I GL::MYC translocations during IG light chain revision, with clinical implications. Significance These findings link BCR silencing in isotype-switched t(14;18)+ Follicular Lymphoma cells (or their precursors) to RAG1/2 re-expression, promoting IGL::MYC translocations responsible for transformation into high-grade B cell lymphomas (HGBCL). Predominant silencing of the BCR complex in HGBCL with MYC and BCL2 rearrangements protects tumor cells from CD79B-directed Polatuzumab-Vedotin killing. ### Competing Interest Statement The authors have declared no competing interest.

Plasmacytoid dendritic cells (pDCs) are multifaceted immune cells executing various innate immunological functions. Their first line of defence consists in type I interferons (I-IFN) production upon nucleic acids sensing through endosomal Toll-like receptor (TLR) 7- and 9-dependent signalling pathways. Type I IFNs are a class of proinflammatory cytokines that have context-dependent functions on cancer immunosurveillance and immunoediting. In the last few years, different studies have reported that pDCs are also able to sense cytosolic DNA through cGAS-STING (stimulator of interferon genes) pathway eliciting a potent I-IFN production independently of TLR7/9. Human pDCs are also endowed with direct effector functions via the upregulation of TRAIL and production of granzyme B, the latter modulated by cytokines abundant in cancer tissues. pDCs have been detected in a wide variety of human malignant neoplasms, including virus-associated cancers, recruited by chemotactic stimuli. Although the role of pDCs in cancer immune surveillance is still uncompletely understood, their spontaneous activation has been rarely documented; moreover, their presence in the tumor microenvironment (TME) has been associated with a tolerogenic phenotype induced by immunosuppressive cytokines or oncometabolites. Currently tested treatment options can lead to pDCs activation and disruption of the immunosuppressive TME, providing a relevant clinical benefit. On the contrary, the antibody-drug conjugates targeting BDCA-2 on immunosuppressive tumor-associated pDCs (TA-pDCs) could be proposed as novel immunomodulatory therapies to achieve disease control in patients with advance stage hematologic malignancies or solid tumors. This Review integrate recent evidence on the biology of pDCs and their pharmacological modulation, suggesting their relevant role at the forefront of cancer immunity.

Supplementary Table S2 from Neurospheres Enriched in Cancer Stem–Like Cells Are Highly Effective in Eliciting a Dendritic Cell–Mediated Immune Response against Malignant Gliomas

10 Tables displaying the clinical features of patient cohorts analyzed in this study, as well as correlation analyses among the clinical features and slan+ cell content.

Abstract Terminal tissue differentiation and function of slan+ monocytes in cancer is largely unexplored. Our recent studies demonstrated that slan+ monocytes differentiate into a distinct subset of dendritic cells (DC) in human tonsils and that slan+ cells colonize metastatic carcinoma-draining lymph nodes. Herein, we report by retrospective analysis of multi-institutional cohorts that slan+ cells infiltrate various types of non-Hodgkin lymphomas (NHL), particularly the diffuse large B-cell lymphoma (DLBCL) group, including the most aggressive, nodal and extranodal, forms. Nodal slan+ cells displayed features of either immature DC or macrophages, in the latter case ingesting tumor cells and apoptotic bodies. We also found in patients with DLBCL that peripheral blood slan+ monocytes, but not CD14+ monocytes, increased in number and displayed highly efficient rituximab-mediated antibody-dependent cellular cytotoxicity, almost equivalent to that exerted by NK cells. Notably, slan+ monocytes cultured in conditioned medium from nodal DLBCL (DCM) acquired a macrophage-like phenotype, retained CD16 expression, and became very efficient in rituximab-mediated antibody-dependent cellular phagocytosis (ADCP). Macrophages derived from DCM-treated CD14+ monocytes performed very efficient rituximab-mediated ADCP, however, using different FcγRs from those used by slan+ macrophages. Our observations shed new light on the complexity of the immune microenvironment of DLBCL and demonstrate plasticity of slan+ monocytes homing to cancer tissues. Altogether, data identify slan+ monocytes and macrophages as prominent effectors of antibody-mediated tumor cell targeting in patients with DLBCL. Significance: slan+ monocytes differentiate into macrophages that function as prominent effectors of antibody-mediated tumor cell targeting in lymphoma. Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/78/13/3544/F1.large.jpg. Cancer Res; 78(13); 3544–59. ©2018 AACR.

Introduction: HIV negative patients (pts) with B cell lymphoma (Ly) carrying MYC rearrangements and BCL2+/-BCL6 translocations [double hit (DHL) or triple hit Ly (THL)] have shown a dismal prognosis when treated with standard chemotherapy. Data about the prognosis of “single hit” Ly, (SHL) are more controverse. In HIV-associated B cell lymphomas (HIV+Ly), scanty data are available on the prevalence and prognostic impact of MYC rearrangements. Methods: This is a retrospective study conducted in 11 European centers with the aim to evaluate the clinical and prognostic impact of MYC rearrangement, evaluated by FISH analysis, in HIV+Ly. We compared HIV+ Ly [diffuse large B cell Ly (DLBCL), B cell Ly unclassifiable, with features intermediate between DLBCL and Burkitt (BCLU), and High grade B cell Ly (HGBL)] with (MYC+) and without (MYC-) MYC rearrangements, treated with standard (R-CHOP or CHOP like) or intensive therapy (iCT) that is, CODOX-IVAC, Carmen trial, GMALL. Results: A total of 161 consecutive pts were enrolled: 49 (30%) were MYC+ and 112 (70%) MYC-. MYC+ pts had higher involvement of central nervous system (CNS) at presentation, higher ki67%, more frequent histology other than DLBCL, translocation of BCL2 and germinal center B phenotype. MYC+ pts received more frequently iCT (45% vs. 20%, p = 0.002). With a median follow-up of 57 months, there were no significant differences in overall survival (OS) and progression-free survival (PFS) between MYC+ and MYC- pts (5 years (y) OS and PFS 55% and 47% in MYC+ and 59% and 53% in MYC- pts). DHL/THL were 10 (13 MYC+ pts did not have data on BCL2/BCL6): compared to 26 SHL they had similar clinical characteristics, but worse outcome with 5y PFS (30% vs. 60%, p = 0.02) and 5y OS (50% vs. 67%, p = 0.07). In univariate analysis IPI≥3, ECOG≥ 2, increased LDH and ki67 < 90% were related to worse OS and PFS while BCL2 translocation with shorter PFS. In multivariate analysis ECOG≥2, elevated LDH and ki67 < 90% maintained their negative impact. In MYC+ pts, iCT was related to better PFS compared to standard therapy (5 y PFS 62% and 35%, p = 0.04) and to a trend of better OS (5 y OS 61% and 52%, p = 0.25) (Figure 1). No pts treated with iCT died from toxicity. Keyword: aggressive B-cell non-Hodgkin lymphoma Conflicts of interests pertinent to the abstract M. Spina Honoraria: GILEAD, Servier, Novartis, Incyte, BeiGene, Istituto Gentili Research funding: MENARINI L. Arcaini Consultant or advisory role Roche, Janssen-Cilag, Verastem, Incyte, EUSA Pharma, Celgene/Bristol Myers Squibb, Kite/Gilead, ADC Therapeutics Research funding: Gilead Sciences Other remuneration: Speakers’ Bureau: EUSA Pharma, Novartis D. Dalu Educational grants: Roche, Gentili, Lilly and Eisai Other remuneration: Gentili, Daikii Sanchio A. Tucci Consultant or advisory role Gentili, Sanofi, Jannsen Honoraria: Kiowa Kyrin, Takeda