A targeted gene signature stratifying mediastinal gray zone lymphoma into classical HL-like or PMBL-like subtypes.

Not available.

Plasmacytoid dendritic cells at the forefront of anti-cancer immunity: rewiring strategies for tumor microenvironment remodeling.

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.

Germinal Center Dark Zone harbors ATR-dependent determinants of T-cell exclusion that are also identified in aggressive lymphoma.

The germinal center (GC) dark zone (DZ) and light zone (LZ) regions spatially separate expansion and diversification from selection of antigen-specific B-cells to ensure antibody affinity maturation and B cell memory. The DZ and LZ differ significantly in their immune composition despite the lack of a physical barrier, yet the determinants of this polarization are poorly understood. This study provides novel insights into signals controlling asymmetric T-cell distribution between DZ and LZ regions. We identify spatially-resolved DNA damage response and chromatin compaction molecular features that underlie DZ T-cell exclusion. The DZ spatial transcriptional signature linked to T-cell immune evasion clustered aggressive Diffuse Large B-cell Lymphomas (DLBCL) for differential T cell infiltration. We reveal the dependence of the DZ transcriptional core signature on the ATR kinase and dissect its role in restraining inflammatory responses contributing to establishing an immune-repulsive imprint in DLBCL. These insights may guide ATR-focused treatment strategies bolstering immunotherapy in tumors marked by DZ transcriptional and chromatin-associated features.

MYC rearrangements in HIV-associated large B-cell lymphomas: EUROMYC, a European retrospective study.

ABSTRACT: Large B-cell lymphoma (LBCL) carrying MYC rearrangement, alone or together with BCL2 and/or BCL6 translocations, have shown a poor prognosis when treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) in the HIV population. Scanty data are available on the prevalence and prognostic impact of MYC rearrangements in HIV-associated LBCL. We conducted a retrospective study to evaluate the clinical effect of MYC rearrangement in HIV-associated LBCL. We evaluated clinical characteristics, treatment received, and outcome of LBCL in patients with HIV with MYC rearrangement (MYC+) and without MYC rearrangement (MYC-). A total of 155 patients with HIV who had received fluorescence in situ hybridization analysis for MYC were enrolled in 11 European centers: 43 with MYC+ and 112 MYC-. Among patients with MYC, 10 had double-/triple-hit lymphomas, and 33 had isolated MYC rearrangement (single-hit lymphoma). Patients with MYC+ had more frequently advanced stage, >2 extranodal site at presentation, and higher proliferative index. There were no significant differences in overall survival and progression-free survival (PFS) between the 2 groups. However, patients with MYC+ received more frequently intensive chemotherapy (iCT) (44%) than (R)CHOP alone (35%) or infusional treatment (DA-EPOCH-R and R-CDE) (19%). Among patients with MYC+, those who received iCT achieved a better outcome than patients who received nonintensive treatment (complete remission, 84% vs 52%; P = .028; 5-year PFS, 66% vs 36%; P = .021). Our retrospective results suggest that HIV-associated LBCL with MYC+ could be considered for an intensive therapeutic approach whenever possible, whereas (R)CHOP seems to give inferior results in this subset of patients in terms of complete remission and PFS.

Massive parallel sequencing unveils homologous recombination deficiency in follicular dendritic cell sarcoma.

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, 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 FISH 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 haematopoietic 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.

Immunoglobulin light chain transcript detection by ultrasensitive RNA in situ hybridization for B-cell lymphoma diagnosis.

Evaluation of B-cell clonality can be challenging in the interpretation of lymphoid infiltrates on tissue sections. Clonality testing based on IG gene rearrangements analysis by PCR (IG-PCR) is the gold standard. Alternatively, B-cell clonality can be assessed by the recognition of immunoglobulin light chain (IgLC) restriction, by immunohistochemistry (IHC), chromogenic in situ hybridization (ISH) or flow cytometry (FC). IG-PCR requires molecular facilities, and FC requires cell suspensions, both not widely available in routine pathology units. This study evaluates the performance of B-cell clonality detection by IgLC-RNAscope® (RNAsc) in a group of 216 formalin-fixed, paraffin-embedded samples including 185 non-Hodgkin B-cell lymphomas, 11 Hodgkin lymphomas (HL) and 20 reactive samples. IgLC-RNAsc, performed in parallel with FC in 53 cases, demonstrated better performances (93% vs 83%), particularly in diffuse large B-cell lymphoma (98% vs 71%) and follicular lymphoma (93% vs 83%) diagnosis. IgLC-RNAsc was also superior to IHC and ISH especially in samples with limited tumor cell content, where IG-PCR was not informative. Performed for the first time on mediastinal lymphomas, IgLC-RNAsc identified monotypic IgLC transcripts in 69% of primary mediastinal large B-cell lymphoma (PMBCL) and 67% of mediastinal gray zone lymphomas (MGZL). IGK/L double-negative cells were detected in 1 PMBCL, 2 MGZL, and all classical HL, while monotypic IgLC expression appeared to be a hallmark in nodular lymphocyte-predominant HL. IgLC-RNAsc demonstrates to be a powerful tool in B-cell lymphoma diagnosis, above all in challenging cases with limited tumor cell content, ensuring in situ investigations on mechanisms of Ig regulation across lymphoma entities.

Parapharyngeal lymph node as an isolated manifestation of follicular dendritic cell sarcoma: First report in Iran.

Follicular dendritic cell sarcoma (FDCS) is a rare type of sarcoma that originates from the stromal component of the germinal center of the B-follicle. Its presentation and prognosis vary, as it can be nodal or extranodal, localized or multifocal, and can be fatal in 20% of cases. Due to its rarity, FDCS diagnosis requires a high level of suspicion. Most cases have been reported in Europe or the United States, and no cases have been previously reported in individuals of Iranian descent. This case report describes a 33-year-old Iranian man with no significant medical history who presented with a palpable nodule in the neck and odynophagia. Magnetic resonance imaging revealed a mass with heterogeneous enhancement in the parapharyngeal space. Pathological examination confirmed FDCS, likely localized to a parapharyngeal lymph node with no extranodal involvement. The patient underwent radiation therapy and remained disease-free 28 months after diagnosis.

Accessory spleens recapitulate the immune microenvironment of the main spleen in immune thrombocytopenia.

Accessory spleens (AcS) may play a relevant role in immune thrombocytopenia (ITP) and possibly contribute to ITP relapse following splenectomy. Little is known about the immune microenvironment of AcS in ITP. To address this issue, we compared the histological features of eight matched AcS and main spleen (MS) samples, obtained from adult patients with primary ITP. AcS and MS had overlapping immune architectural features and lymphoid composition, suggesting that similar immunologic events occur in AcS and MS of ITP. These findings may have implications for the potential mechanisms of AcS-mediated ITP relapse. Further studies are needed to confirm these results and to dissect spleen immunity in ITP.

Pathomorphogenesis of Glycogen-Ground Glass Hepatocytic Inclusions (Polyglucosan Bodies) in Children after Liver Transplantation.

Seventeen out of 764 liver biopsies from transplanted (Tx) livers in children showed glycogen-ground glass (GGG) hepatocytic inclusions. The inclusions were not present in pre-Tx or in the explanted or donor's liver. Under the electron microscope (EM), the stored material within the cytosol appeared as non-membrane-bound aggregates of electron-lucent globoid or fibrillar granules, previously described as abnormally structured glycogen and identified as Polyglucosan bodies (PB). The appearance of GGG in our children was analogous to that of PB-GGG occurring in a number of congenital diseases due to gene mutations such as Lafora's d., Andersen's d., Adult Polyglucosan Body Disease and glycogenin deficiency. The same type of GGG was previously reported in the liver of patients undergoing transplants, immunosuppressive or antiblastic treatment. To explore the potential mechanism of GGG formation, we examined whether the drugs after whose treatment this phenomenon was observed could have a role. By carrying out molecular docking, we found that such drugs somehow present a high binding affinity for the active region of glycogenin, implicating that they can inactivate the protein, thus preventing its interaction with glycogen synthase (GS), as well as the maturation of the nascent glycogen towards gamma, beta or alfa glycogen granules. We could also demonstrate that PG inclusions consist of a complex of PAS positive material (glycogen) and glycogen-associated proteins, i.e., glicogenin-1 and -2 and ubiquitin. These features appear to be analogous to congenital GGG, suggesting that, in both cases, they result from the simultaneous dysregulation of glycogen synthesis and degradation. Drug-induced GGG appear to be toxic to the cell, despite their reversibility.

International Consensus Classification of Myeloid Neoplasms and Acute Leukemias: integrating morphologic, clinical, and genomic data.

The classification of myeloid neoplasms and acute leukemias was last updated in 2016 within a collaboration between the World Health Organization (WHO), the Society for Hematopathology, and the European Association for Haematopathology. This collaboration was primarily based on input from a clinical advisory committees (CACs) composed of pathologists, hematologists, oncologists, geneticists, and bioinformaticians from around the world. The recent advances in our understanding of the biology of hematologic malignancies, the experience with the use of the 2016 WHO classification in clinical practice, and the results of clinical trials have indicated the need for further revising and updating the classification. As a continuation of this CAC-based process, the authors, a group with expertise in the clinical, pathologic, and genetic aspects of these disorders, developed the International Consensus Classification (ICC) of myeloid neoplasms and acute leukemias. Using a multiparameter approach, the main objective of the consensus process was the definition of real disease entities, including the introduction of new entities and refined criteria for existing diagnostic categories, based on accumulated data. The ICC is aimed at facilitating diagnosis and prognostication of these neoplasms, improving treatment of affected patients, and allowing the design of innovative clinical trials.

Safety and efficacy of a dose-dense short-term therapy in patients with MYC-translocated aggressive lymphoma.

Patients with aggressive B-cell lymphoma and MYC rearrangement at fluorescence in situ hybridization exhibit poor outcome after R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone). In the last decade, 68 patients with Burkitt lymphoma ([BL] n = 46) or high-grade B-cell lymphoma ([HGBCL] single, double, or triple hit; n = 22) were treated with a dose-dense, short-term therapy termed "CARMEN regimen" at 5 Italian centers. Forty-six (68%) patients were HIV+. CARMEN included a 36-day induction with sequential, single weekly doses of cyclophosphamide, vincristine, rituximab, methotrexate, etoposide, and doxorubicin plus intrathecal chemotherapy, followed by high-dose-cytarabine-based consolidation. Patients who did not achieve complete remission (CR) after induction received BEAM (carmustina, etoposide, cytarabine, melfalan)-conditioned autologous stem cell transplantation (ASCT) after consolidation. Sixty-one (90%) patients completed induction, and 59 (87%) completed consolidation. Seventeen patients received ASCT. Grade 4 hematological toxicity was common but did not cause treatment discontinuation; grade 4 nonhematological toxicity was recorded in 11 (16%) patients, with grade 4 infections in 6 (9%). Six (9%) patients died of toxicity (sepsis in 4, COVID-19, acute respiratory distress syndrome). CR rate after the whole treatment was 73% (95% confidence interval [CI], 55% to 91%) for patients with HGBCL and 78% (95% CI, 66% to 90%) for patients with BL. At a median follow-up of 65 (interquartile range, 40-109) months, 48 patients remain event free, with a 5-year progression-free survival of 63% (95% CI, 58% to 68%) for HGBCL and 72% (95% CI, 71% to 73%) for BL, with a 5-year overall survival (OS) of 63% (95% CI, 58% to 68%) and 76% (95% CI, 75% to 77%), respectively. HIV seropositivity did not have a detrimental effect on outcome. This retrospective study shows that CARMEN is a safe and active regimen both in HIV-negative and -positive patients with MYC-rearranged lymphomas. Encouraging survival figures, attained with a single dose of doxorubicin and cyclophosphamide, deserve further investigation in HGBCL and other aggressive lymphomas.

Clinical and Histological Prognostic Factors of Recurrence and Malignant Transformation in a Large Series of Oral Potentially Malignant Disorders.

Background: Oral potentially malignant disorders (OPMDs) represent a heterogeneous set of different histological lesions, characterized by the capacity to transform in oral squamous cell carcinoma (OSCC). Despite optimal surgical treatment, approximately 20%-30% of OPMDs may evolve into OSCC. No clear clinical/histological factors are able to identify OPMDs at higher risk of malignant transformation. Materials and Methods: We considered surgically treated patients with a diagnosis of OPMDs, enrolled from 1996 to 2019 at ASST Spedali Civili of Brescia without a diagnosis of OSCC within the previous 2 years. Clinical and histological characteristics were recorded. Outcomes of interest were recurrence-free survival (RFS), defined as the time from surgery for primary OPMD to any relapse of OPMD or malignant transformation, whichever occurred first, and carcinoma-free survival (CFS), defined as the time from surgery for OPMD to malignant transformation. Results: We retrospectively reviewed 106 OPMDs cases. Median age at first diagnosis was 64 years old (IQR = 18.75); female patients comprise 51.9% of the cases. During a median follow-up of 30.5 months (IQR = 44), in 23.5% of patients, malignant transformation occurred. RFS at 1, 5, and 10 years was 92.4%, 60.9%, and 43.2%, respectively. Female sex and history of previous OSCC were independent risk factors for RFS. CFS at 1, 5, and 10 years of follow-up was 97.1%, 75.9%, and 64.4%, respectively. Previous OSCC was an independent risk factor for CFS. Conclusions: In this large series of OPMDs, only previous diagnosis of OSCC was a prognostic factor for further OSCC occurrence. Given the lack of additional clinical/pathological prognostic factors, we advocate further studies into molecular characterization of OPMDs to better stratify the risk of malignant transformation.

Immunohistochemical Detection of SARS-CoV-2 Antigens by Single and Multiple Immunohistochemistry.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can be demonstrated in tissue sections by immunohistochemistry (IHC), which has the power to localize in bright field specific antigens in cells and tissues. The use of double or triple immunostains is capable of highlighting which cells are infected and/or the relationship of infected cell with other cells and tissue structures. In addition, immunoenzymatic multi-staining permits the simultaneous identification, localization, and enumeration of different cellular epitopes. Moreover, this method improves analytical precision, decreasing the time required for morphometric quantification, maximizing the information obtained from a single slide of paraffin-embedded tissue.

Spatial transcriptome of a germinal center plasmablastic burst hints at MYD88/CD79B mutants-enriched diffuse large B-cell lymphomas.

The GC reaction results in the selection of B cells acquiring effector Ig secreting ability by progressing toward plasmablastic differentiation. This transition is associated with exclusion from the GC microenvironment. The aberrant expansion of plasmablastic elements within the GC fringes configures an atypical condition, the biological characteristics of which have not been defined yet. We investigated the in situ immunophenotypical and transcriptional characteristics of a nonclonal germinotropic expansion of plasmablastic elements (GEx) occurring in the tonsil of a young patient. Compared to neighboring GC and perifollicular regions, the GEx showed a distinctive signature featuring key regulators of plasmacytic differentiation, cytokine signaling, and cell metabolism. The GEx signature was tested in the setting of diffuse large B-cell lymphoma (DLBCL) as a prototypical model of lymphomagenesis encompassing transformation at different stages of GC and post-GC functional differentiation. The signature outlined DLBCL clusters with different immune microenvironment composition and enrichment in genetic subtypes. This report represents the first insight into the transcriptional features of a germinotropic plasmablastic burst, shedding light into the molecular hallmarks of B cells undergoing plasmablastic differentiation and aberrant expansion within the noncanonical setting of the GC microenvironment.

Genetic and phenotypic attributes of splenic marginal zone lymphoma.

Splenic marginal zone B-cell lymphoma (SMZL) is a heterogeneous clinico-biological entity. The clinical course is variable, multiple genes are mutated with no unifying mechanism, and essential regulatory pathways and surrounding microenvironments are diverse. We sought to clarify the heterogeneity of SMZL by resolving different subgroups and their underlying genomic abnormalities, pathway signatures, and microenvironment compositions to uncover biomarkers and therapeutic vulnerabilities. We studied 303 SMZL spleen samples collected through the IELSG46 multicenter international study (NCT02945319) by using a multiplatform approach. We carried out genetic and phenotypic analyses, defined self-organized signatures, validated the findings in independent primary tumor metadata and in genetically modified mouse models, and determined correlations with outcome data. We identified 2 prominent genetic clusters in SMZL, termed NNK (58% of cases, harboring NF-κB, NOTCH, and KLF2 modules) and DMT (32% of cases, with DNA-damage response, MAPK, and TLR modules). Genetic aberrations in multiple genes as well as cytogenetic and immunogenetic features distinguished NNK- from DMT-SMZLs. These genetic clusters not only have distinct underpinning biology, as judged by differences in gene-expression signatures, but also different outcomes, with inferior survival in NNK-SMZLs. Digital cytometry and in situ profiling segregated 2 basic types of SMZL immune microenvironments termed immune-suppressive SMZL (50% of cases, associated with inflammatory cells and immune checkpoint activation) and immune-silent SMZL (50% of cases, associated with an immune-excluded phenotype) with distinct mutational and clinical connotations. In summary, we propose a nosology of SMZL that can implement its classification and also aid in the development of rationally targeted treatments.

Dose-adjusted EPOCH and rituximab for the treatment of double expressor and double-hit diffuse large B-cell lymphoma: impact of TP53 mutations on clinical outcome.

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease, including one-third of cases overexpressing MYC and BCL2 proteins (double expressor lymphoma, DEL) and 5-10% of patients with chromosomal rearrangements of MYC, BCL2 and/or BCL-6 (double/triple-hit lymphomas, DH/TH). TP53 mutations are detected in 20- 25% of DEL. We report the efficacy of dose-adjusted EPOCH and rituximab (DA-EPOCH-R) in a series of 122 consecutive patients, including DEL (n=81, 66%), DEL-MYC (n=9, 7%), DEL-BCL2 (n=13, 11%), or high-grade lymphomas (DH/TH) (n=19, 16%). Central nervous system (CNS) prophylaxis included intravenous methotrexate (n=66), intrathecal chemotherapy (IT) (n=40) or no prophylaxis (n=16). Sixty-seven patients (55%) had highintermediate or high International Prognostic Index (IPI) and 30 (25%) had high CNS-IPI. The 2-year progression-free survival (PFS) and overall survival (OS) for the entire study population were 74% and 84%, respectively. There was a trend for inferior OS for DH/TH (2-year OS: 66%, P=0.058) as compared to all the others. The outcome was significantly better for the IPI 0-2 versus IPI 3-5 (OS: 98% vs. 72%, P=0.002). DA-EPOCH-R did not overcome the negative prognostic value of TP53 mutations: 2-year OS of 62% versus 88% (P=0.036) were observed for mutated as compared to wild-type cases, respectively. Systemic CNS prophylaxis conferred a better 2-year OS (94%) as compared to IT or no prophylaxis (76% and 65%, respectively; P=0.008). DA-EPOCH-R treatment resulted in a favorable outcome in patients with DEL and DEL with single rearrangement, whereas those with multiple genetic alterations such as DEL-DH/TH and TP53 mutated cases still have an inferior outcome.

Cardiac lymphoma with early response to chemotherapy: A case report and review of the literature.

Cardiac tumors are rare and benign masses account for the most part of the diagnosis. When malignant cancer is detected, primary or secondary cardiac lymphoma are quite frequent. Cardiac lymphoma may present as an intra or peri-cardiac mass or, rarely, it may diffusely infiltrate the myocardium. Although often asymptomatic, patients can have non-specific symptoms. Acute presentations with cardiogenic shock, unstable angina, or acute myocardial infarction are also described. Modern imaging techniques can help the clinicians not only in the diagnostic phase but also during administration of chemotherapy. A multidisciplinary counseling and serial multi-parametric assessment (echocardiography, cardiac troponin) seem to be the most effective approach to prevent possible fatal complications (i.e., cardiac rupture). Currently, only chemo- and radiotherapy are available options for treatment, but the prognosis remains poor. This is a case of secondary cardiac lymphoma presenting as a mediastinal mass with large infiltration of the heart and the great vessels with a good improvement after only one cycle of chemotherapy. It demonstrates the importance of an early diagnosis to modify the natural history of the disease.