Nasal NK/T-cell lymphoma: epidemiology and pathogenesis

Immunotyping of peripheral blood lymphocytes by flow cytometry reveals Th cell as a potential prognostic biomarker for extranodal NK/T-cell lymphoma

This study aimed to explore the distribution, characteristics and prognostic value of baseline peripheral blood lymphocyte subsets in patients with extranodal NK/T-cell lymphoma (NKTCL). We conducted this cross-sectional study of 205 newly-diagnosed NKTCL patients receiving first-line chemotherapy and radiation at our institute between 2010 and 2020. Baseline peripheral blood lymphocytes were detected using flow cytometry, and the clinical value was analyzed. Compared with healthy controls, patients with NKTCL presented with a distinct peripheral immunity with higher levels of cytotoxic CD8+ T cells (33.230 ± 12.090% vs. 27.060 ± 4.010%, p < 0.001) and NKT cells (7.697 ± 7.219% vs. 3.550 ± 2.088%, p < 0.001) but lower proportions of suppressive regulatory T cells (Treg, 2.999 ± 1.949% vs. 3.420 ± 1.051%, p = 0.003) and CD4+ helper T cells (Th, 33.084 ± 11.361% vs. 37.650 ± 3.153%, p < 0.001). Peripheral lymphocytes were differentially distributed according to age, stage, and primary site in patients with NKTCL. The proportion of Th cells/lymphocytes was associated with tumor burden reflected by stage (p = 0.037), serum lactate dehydrogenase (p = 0.0420), primary tumor invasion (p = 0.025), and prognostic index for NK/T-cell lymphoma (PINK) score (p = 0.041). Furthermore, elevated proportions of T cells (58.9% vs. 76.4%, p = 0.005), Th cells (56.3% vs. 68.8%, p = 0.047), or Treg cells (49.5% vs. 68.9%, p = 0.040) were associated with inferior 5-year progression-free survivals (PFS) via univariable survival analysis. Multivariate cox regression revealed elevated Th cells as an independent predictor for unfavorable PFS (HR = 2.333, 95% CI, 1.030-5.288, p = 0.042) in NKTCL. These results suggested the proportion of Th cells positively correlated with tumor burden and was a potential non-invasive biomarker for inferior survival for patients with NKTCL.

Extranodal NK/T-Cell Lymphoma Predominantly Composed of Anaplastic Cells: A Frequently Misdiagnosed and Highly Aggressive Variant

Extranodal NK/T-cell lymphoma (ENKTL) is a non-Hodgkin lymphoma associated with the Epstein-Barr virus that primarily affects individuals in East Asia and indigenous populations in Central and South America. Morphologically, ENKTL typically consists of medium-sized cells or a combination of small and large cells. This report presents 10 cases characterized by predominantly anaplastic cells with diffuse expression of CD30, resembling anaplastic lymphoma kinase-negative anaplastic large cell lymphoma (ALK-negative ALCL) and demonstrating highly aggressive behavior. The cohort included 9 males and 1 female, ranging in age from 29 to 65 years (median age: 47 y). Eight patients presented with nasal disease, while 2 had non-nasal disease. Five patients had stage I/II disease, and the remaining 5 had stage III/IV disease. Morphologically, necrosis was observed in 9 cases, angiocentric-angiodestructive growth in 3 cases, and pseudoepitheliomatous hyperplasia in 2 cases. Anaplastic cells predominated in all cases, with some displaying eccentric, horseshoe-shaped, or kidney-shaped nuclei (referred to as "Hallmark" cells). The morphology profile was monomorphic in 3 cases and polymorphic in 7 cases. Immunohistochemically, all cases tested positive for cytotoxic granule markers (TIA1 and granzymeB) and Epstein-Barr virus-encoded RNA. Cytoplasmic expression of CD3ε and CD56 was observed in 9 of 10 cases. Interestingly, most cases (7 of 8) exhibited variable expression of MuM1, ranging from 10% to 90%. All cases showed diffuse positivity for CD30 but were negative for ALK, resulting in 3 cases being initially misdiagnosed as ALK-negative ALCL. Compared with nonanaplastic cases, anaplastic cells predominant ENKTL had a significantly higher frequency of "B" symptoms, bone marrow involvement, hemophagocytic lymphohistiocytosis, and higher Ki67 proliferative index. These findings provide valuable information for pathologists, expanding their understanding of the cytologic spectrum of ENKTL. This rare variant of ENKTL, characterized by the predominance of anaplastic cells and diffuse CD30 expression, exhibits high aggressiveness and should be differentiated from ALK-negative ALCL. Awareness of this uncommon variant is crucial in preventing misdiagnosis and ensuring the timely initiation of therapy.

Testicular germ cell tumors: Genomic alternations and RAS-dependent signaling

Testicular germ cell tumors (TGCTs) are a common malignancy occurring in young adult men. The various genetic risk factors have been suggested to contribute to TGCT pathogenesis, however, they have a distinct mutational profile with a low rate of somatic point mutations, more frequent chromosomal gains, and aneuploidy. The most frequently mutated oncogenes in human cancers are RAS oncogenes, while their impact on testicular carcinogenesis and refractory disease is still poorly understood. In this mini-review, we summarize current knowledge on genetic alternations of RAS signaling-associated genes (the single nucleotide polymorphisms and point mutations) in this particular cancer type and highlight their link to chemotherapy resistance mechanisms. We also mention the impact of epigenetic changes on TGCT progression. Lastly, we propose a model for RAS-dependent signaling networks, regulation, cross-talks, and outcomes in TGCTs.

Kayadiol exerted anticancer effects through p53-mediated ferroptosis in NKTCL cells

BACKGROUND

Extranodal natural killer/T cell lymphoma (NKTCL) is a highly aggressive type of non-Hodgkin lymphoma that facing the treatment challenges. Natural compounds are important sources for drug development because of their diverse biological and chemical properties, among which terpenoids have strong anticancer activities.

METHODS

The human NK/T cell lymphoma cell line YT and peripheral blood lymphocytes isolated from NKTCL patients were treated with different concentrations of kayadiol. Then, the following experiments were performed: CCK-8 assay for cell viability, reactive oxygen species (ROS) and glutathione (GSH) assay and co-treatment with NAC, reduced GSH, or ferrostatin-1 for ferroptosis, the proteome profiling for elucidating signaling pathways, and western blot for the expression of p53, SCL7A11, and GPX4. siRNA and CRISPR/Cas9 plasmid for p53 knockout was designed and transfected into YT cells to evaluate the causal role of p53 in kayadiol-induced ferroptosis. The synergistic effect was evaluated by CCK8 assay after co-treatment of kayadiol with L-asparaginase or cisplatin.

RESULTS

In this study, we found that kayadiol, a diterpenoid extracted from Torreya nucifera, exerted significant killing effect on NKTCL cells without killing the healthy lymphocytes. Subsequently, we observed that kayadiol treatment triggered significant ferroptosis events, including ROS accumulation and GSH depletion. ROS scavenger NAC, GSH, and ferroptosis inhibitor ferrostatin-1 (Fer-1) reversed kayadiol-induced cell death in NKTCL cells. Furthermore, kayadiol decreased the expression of SLC7A11 and GPX4, the negative regulatory proteins for ferroptosis. We then demonstrated that p53 was the key mediator of kayadiol-induced ferroptosis by SLC7A11/GPX4 axis through p53 knockout experiments. In addition, kayadiol exerted a synergistic effect with L-asparaginase and cisplatin in NKTCL cells.

CONCLUSION

Taken together, our results suggested that the natural product kayadiol exerted anticancer effects through p53-mediated ferroptosis in NK/T cell lymphoma cells. Hence, it can serve as an effective alternative in the treatment of NK/T cell lymphoma, especially for patients exhibiting chemoresistance.

Refractory Hydroa Vacciniforme-like Lymphoma: Biological Insights from Morphoproteomic Analysis

T-cell/natural killer cell lymphoproliferative disorders are rare, associated with poor overall survival, and have limited treatment options. We report a case of a patient who developed hydroa vacciniforme-like lymphoma (HVLL, an EBV-peripheral T-cell lymphoma), refractory to multiple lines of systemic therapy including methotrexate, mycophenolate mofetil, dapsone, thalidomide, prednisone, and romidepsin. We conducted morphoproteomic analysis of the patient's tumor which provided important biological insights. Histopathology showed primarily lymphohistiocytic infiltrates strongly positive EBV expression with a Ki-67 of >50% in the pretreatment biopsy and approximately 90% in the post-treatment biopsy, strong expression of Enhancer of Zester Homolog 2 (EZH2), a constitutively active mTOR pathway, 50% cytoplasmic BCL-2 expression; largely negative PD-1 positive CD8 T-cells. Based on this morphoproteomic analysis and published literature, we postulated that novel agents, including venetoclax, tazemetostat, and other agents may provide a targeted approach for treating HVLL. This case illustrates the use of morphoproteomic analysis to better understand the biology of tumors.

Epstein-Barr Virus in Burkitt Lymphoma in Africa Reveals a Limited Set of Whole Genome and LMP-1 Sequence Patterns: Analysis of Archival Datasets and Field Samples From Uganda, Tanzania, and Kenya

Epstein-Barr virus (EBV) is associated with endemic Burkitt lymphoma (eBL), but the contribution of EBV variants is ill-defined. Studies of EBV whole genome sequences (WGS) have identified phylogroups that appear to be distinct for Asian versus non-Asian EBV, but samples from BL or Africa, where EBV was first discovered, are under-represented. We conducted a phylogenetic analysis of EBV WGS and LMP-1 sequences obtained primarily from BL patients in Africa and representative non-African EBV from other conditions or regions using data from GenBank, Sequence Read Archive, or Genomic Data Commons for the Burkitt Lymphoma Genome Sequencing Project (BLGSP) to generate data to support the use of a simpler biomarker of geographic or phenotypic associations. We also investigated LMP-1 patterns in 414 eBL cases and 414 geographically matched controls in the Epidemiology of Burkitt Lymphoma in East African children and minors (EMBLEM) study using LMP-1 PCR and Sanger sequencing. Phylogenetic analysis revealed distinct genetic patterns of African versus Asian EBV sequences. We identified 281 single nucleotide variations (SNVs) in LMP-1 promoter and coding region, which formed 12 unique patterns (A to L). Nine patterns (A, AB, C, D, F, I, J, K and L) predominated in African EBV, of which four were found in 92% of BL samples (A, AB, D, and H). Predominant patterns were B and G in Asia and H in Europe. EBV positivity in peripheral blood was detected in 95.6% of EMBLEM eBL cases versus 79.2% of the healthy controls (odds ratio [OR] =3.83; 95% confidence interval 2.06-7.14). LMP-1 was successfully sequenced in 66.7% of the EBV DNA positive cases but in 29.6% of the controls (ORs ranging 5-11 for different patterns). Four LMP-1 patterns (A, AB, D, and K) were detected in 63.1% of the cases versus 27.1% controls (ORs ranges: 5.58-11.4). Dual strain EBV infections were identified in WGS and PCR-Sanger data. In conclusion, EBV from Africa is phylogenetically separate from EBV in Asia. Genetic diversity in LMP-1 formed 12 patterns, which showed promising geographic and phenotypic associations. Presence of multiple strain infection should be considered in efforts to refine or improve EBV markers of ancestry or phenotype.

Lay Summary

Epstein-Barr virus (EBV) infection, a ubiquitous infection, contributes to the etiology of both Burkitt Lymphoma (BL) and nasopharyngeal carcinoma, yet their global distributions vary geographically with no overlap. Genomic variation in EBV is suspected to play a role in the geographical patterns of these EBV-associated cancers, but relatively few EBV samples from BL have been comprehensively studied. We sought to compare phylogenetic patterns of EBV genomes obtained from BL samples in Africa and from tumor and non-tumor samples from elsewhere. We concluded that EBV obtained from BL in Africa is genetically separate from EBV in Asia. Through comprehensive analysis of nucleotide variations in EBV's LMP-1 gene, we describe 12 LMP-1 patterns, two of which (B and G) were found mostly in Asia. Four LMP-1 patterns (A, AB, D, and F) accounted for 92% of EBVs sequenced from BL in Africa. Our results identified extensive diversity of EBV, but BL in Africa was associated with a limited number of variants identified, which were different from those identified in Asia. Further research is needed to optimize the use of PCR and sequencing to study LMP-1 diversity for classification of EBV variants and for use in epidemiologic studies to characterize geographic and/or phenotypic associations of EBV variants with EBV-associated malignancies, including eBL.

EBV associated T- and NK-cell lymphoproliferative diseases: A comprehensive overview of clinical manifestations and novel therapeutic insights

EBV is a ubiquitous virus that infects nearly all people around the world. Most infected people are asymptomatic and do not show serious sequelae, while others may develop Epstein-Barr virus (EBV)-positive T and NK-cell lymphoproliferations characterised by EBV-infected T or NK cells. These disorders are more common in Asian and Latin American people, suggesting genetic predisposition as a contributing factor. The revised WHO classification classifies the lymphoproliferative diseases as: extranodal NK/T-cell lymphoma nasal type (ENKTL), aggressive NK-cell leukemia (ANKL), primary EBV-positive nodal T or NK cell lymphoma (NNKTL), systemic EBV-positive T-cell lymphoproliferative disease of childhood (STCLC), systemic chronic active EBV infection (sys CAEBV), hydroa-vacciniforme (HV) and severe mosquito bite allergy (SMBA). Recent advances in the molecular pathogenesis of these diseases have led to the development of new therapeutic strategies. Due to the infrequency of the diseases and broad clinicopathological overlap, the diagnosis and classification are challenging for both clinicians and pathologists. In this article, we aim to review the recent pathological findings which can be helpful for designing new drugs, clinical presentations and differential diagnoses, and suggested therapeutic interventions to provide a better understanding of these rare disorders.

EBV Genome Mutations and Malignant Proliferations

The Epstein-Barr virus (EBV) is a DNA virus with a relatively stable genome. Indeed, genomic variability is reported to be around 0.002%. However, some regions are more variable such as those carrying latency genes and specially EBNA1, -2, -LP, and LMP1. Tegument genes, particularly BNRF1, BPLF1, and BKRF3, are also quite mutated. For a long time, it has been considered for this ubiquitous virus, which infects a very large part of the population, that particular strains could be the cause of certain diseases. However, the mutations found, in some cases, are more geographically restricted rather than associated with proliferation. In other cases, they appear to be involved in oncogenesis. The objective of this chapter is to provide an update on changes in viral genome sequences in malignancies associated with EBV. We focused on describing the structure and function of the proteins corresponding to the genes mentioned above in order to understand how certain mutations of these proteins could increase the tumorigenic character of this virus. Mutations described in the literature for these proteins were identified by reporting viral and/or cellular functional changes as they were described.

Characterization of the humoral immune response to the EBV proteome in extranodal NK/T-cell lymphoma

Extranodal natural killer/T-cell lymphoma (NKTCL) is an aggressive malignancy that has been etiologically linked to Epstein-Barr virus (EBV) infection, with EBV gene transcripts identified in almost all cases. However, the humoral immune response to EBV in NKTCL patients has not been well characterized. We examined the antibody response to EBV in plasma samples from 51 NKTCL cases and 154 controls from Hong Kong and Taiwan who were part of the multi-center, hospital-based AsiaLymph case–control study. The EBV-directed serological response was characterized using a protein microarray that measured IgG and IgA antibodies against 202 protein sequences representing the entire EBV proteome. We analyzed 157 IgG antibodies and 127 IgA antibodies that fulfilled quality control requirements. Associations between EBV serology and NKTCL status were disproportionately observed for IgG rather than IgA antibodies. Nine anti-EBV IgG responses were significantly elevated in NKTCL cases compared with controls and had ORs_{highest vs. lowest tertile} > 6.0 (Bonferroni-corrected P-values < 0.05). Among these nine elevated IgG responses in NKTCL patients, three IgG antibodies (all targeting EBNA3A) are novel and have not been observed for other EBV-associated tumors of B-cell or epithelial origin. IgG antibodies against EBNA1, which have consistently been elevated in other EBV-associated tumors, were not elevated in NKTCL cases. We characterize the antibody response against EBV for patients with NKTCL and identify IgG antibody responses against six distinct EBV proteins. Our findings suggest distinct serologic patterns of this NK/T-cell lymphoma compared with other EBV-associated tumors of B-cell or epithelial origin.

Characteristics and Clinical Implications of the Nasal Microbiota in Extranodal NK/T-Cell Lymphoma, Nasal Type

Natural killer/T cell lymphoma (NKTCL) most frequently affects the nasal cavity and upper aerodigestive tract (UAT) and is often mistaken for reactive disease processes, such as chronic rhinosinusitis (CRS). Recently, alterations of the nasal resident microbiota have been found in CRS. However, nasal microbial features in NKTCL have never been reported. This case-control study collected 46 NKTCL patients, 25 CRS patients and 24 matched healthy controls (HCs) to analyze nasal microbial profiles via 16S rRNA sequencing technology to improve our understanding of changes in the nasal microbiota in NKTCL. We found that alpha diversity was significantly decreased, while beta diversity was significantly increased in NKTCL compared with those in CRS and HCs. The genus Corynebacterium was significantly depleted in CRS and NKTCL versus that in HCs, while genus Staphylococcus was the most abundant in the NKTCL compared to that in the other two groups. The nasal microbial community was significantly different between UAT-NKTCL and non-UAT NKTCL patients. Importantly, based on a panel of taxa, excellent classification power with an AUC of 0.875 between UAT-NKTCL and CRS was achieved. Furthermore, the alpha diversity of the nasal microbiota was associated with several clinical covariates of NKTCL. Finally, PICRUSt analysis implicated an array of distinct functions in NKTCL that might be involved in the pathogenesis of the disease. In conclusion, the nasal microbial profile was unique in NKTCL. The nose-microbiota-UAT NKTCL axis represents a panel of promising biomarkers for clinical practice and contributes to revealing the potential pathogenesis of this malignancy.

Interleukin-6 reverses Adriamycin resistance in nasal NK/T-cell lymphoma via downregulation of ABCC4 and inactivation of the JAK2/STAT3/NF-κB/P65 pathway

Chemotherapy is generally effective for extranodal natural killer (NK)/T-cell lymphoma (ENKTCL), nasal type. Nevertheless, multidrug resistance (MDR) remains a key challenge in treating nasal NK/T-cell lymphoma. Interleukin-6 (IL-6) is reportedly an important regulator of MDR in many cancers, implicating a role of IL-6 in the chemotherapy response. However, the effects and mechanism of IL-6 in nasal NK/T-cell lymphoma remain unclear. Herein, we demonstrated that the IL-6 serum level was decreased in nasal NK/T-cell lymphoma patients compared to chronic rhinitis patients. Lower serum levels of IL-6 were closely correlated with Ki67 expression and patient survival. ATP-binding cassette (ABC) drug transporter ABCC4 in patients was abnormally upregulated. IL-6 significantly inhibited resistance to Adriamycin (ADM) in ADM-resistant SNK-6 cells (SNK-6/ADM). Moreover, IL-6 resulted in cell cycle arrest and led to apoptosis in SNK-6/ADM cells. Furthermore, IL-6 decreased ABCC4, p-JAK2, p-STAT3, and phospho-NF-κB p65 expression in SNK-6/ADM cells. IL-6 in combination with ADM inhibited tumor growth and increased the survival of SNK-6/ADM xenograft mice. In conclusion, our findings suggest that IL-6 can inhibit the upregulation of ABCC4 and inactivate the JAK2/STAT3/NF-κB/P65 pathway to sensitize NK/T-cell lymphoma to ADM, indicating that combination therapy with IL-6 and other chemotherapeutic drugs may be effective in reversing acquired resistance in nasal NK/T-cell lymphoma.

Epstein-Barr Virus-Associated T- and NK-Cell Lymphoproliferative Diseases: A Review of Clinical and Pathological Features

Simple Summary

In most Epstein–Barr virus (EBV)-infected individuals, the virus establishes a lifelong latent infection with no specific clinical manifestation. However, EBV primary infection and secondary reactivation may cause various EBV-associated lymphoproliferative disorders (LPD), including hematologic malignancies. Among them, EBV-positive T/NK LPD are uncommon diseases defined by the proliferation of T- or NK-cells infected by EBV, more commonly encountered in Asians and Latin Americans. They encompass a spectrum of disorders ranging from indolent reactive lesions to malignant and aggressive diseases. Despite novel insights from high-throughput molecular studies, the pathogenesis of these disorders is not well understood, and EBV-positive T/NK LPD diagnoses remain challenging due to their rarity and considerable overlap. Indeed, this article discusses new insights into EBV-positive T/NK LPD and focuses on diagnosis challenges, describing the difficulties to clarify the borders between overlapping LPD subtypes.

Abstract

Epstein–Barr virus (EBV) is a ubiquitous virus detected in up to 95% of the general population. Most people are asymptomatic, while some may develop a wide range of EBV-associated lymphoproliferative disorders (LPD). Among them, EBV-positive T/NK LPD are uncommon diseases defined by the proliferation of T- or NK-cells infected by EBV. The 2017 World Health Organization (WHO) classification recognizes the following entities characterized by different outcomes: chronic active EBV infection of T- or NK-cell types (cutaneous and systemic forms), systemic EBV-positive T-cell lymphoma of childhood, EBV-positive aggressive NK-cell leukemia, extra nodal NK/T-cell lymphoma nasal type, and the new provisional entity known as primary EBV-positive nodal T/NK-cell lymphoma. In addition, EBV associated-hemophagocytic lymphohistiocytosis is part of EBV-positive T/NK LPD, but has not been included in the WHO classification due to its reactive nature. Despite novel insights from high-throughput molecular studies, EBV-positive NK/T-cell LPD diagnoses remain challenging, especially because of their rarity and overlap. Until now, an accurate EBV-positive NK/T LPD diagnosis has been based on its clinical presentation and course correlated with its histological features. This review aims to summarize clinical, pathological and molecular features of EBV-positive T/NK LPD subtypes and to provide an overview of new understandings regarding these rare disorders.

NK/T-cell lymphoma of the nasal cavity: an unexpected diagnosis

Nasal-type Natural Killer/T-cell Lymphoma (NKTL) is a rare form of extranodal non-Hodgkin's lymphoma, typically arising in the nasopharynx and displaying an aggressive and ultimately fatal clinical course. The disease is linked to Epstein-Barr virus infection and is endemic to Asia and South America, but extremely few cases have been reported in Europe. We present two cases of nasal NKTL unexpectedly diagnosed in elderly patients, following very different presentations to our otolaryngology service. The first case is that of a 73-year-old Irish man with recurrent nasal vestibulitis despite antibiotic treatment. The second case involves a 79-year-old Irish woman presenting with a large mass on the hard palate, found to invade into the floor of the nose. NKTL can pose diagnostic challenges, as the initial clinical presentation can be non-specific and overlap with other nasal conditions, leading to a delay in diagnosis. Biopsy with histopathological and immunohistochemistry analysis is required to establish the definitive diagnosis. Treatment involves multidisciplinary input from radiotherapy and medical oncologists. Clinicians must be aware of this disease and have an index of suspicion when dealing with persistent or aggressive nasal conditions.

EBV and the Pathogenesis of NK/T Cell Lymphoma

Epstein-Barr virus (EBV) is a ubiquitous gamma herpes virus with tropism for B cells. EBV is linked to the pathogenesis of B cell, T cell and NK cell lymphoproliferations, with extranodal NK/T cell lymphoma, nasal type (ENKTCL) being the prototype of an EBV-driven lymphoma. ENKTCL is an aggressive neoplasm, particularly widespread in East Asia and the native population of Latin America, which suggests a strong genetic predisposition. The link between ENKTCL and different populations has been partially explored. EBV genome sequencing analysis recognized two types of strains and identified variants of the latent membrane protein 1 (LMP1), which revealed different oncogenic potential. In general, most ENKTCL patients carry EBV type A with LMP1 wild type, although the LMP1 variant with a 30 base pair deletion is also common, especially in the EBV type B, where it is necessary for oncogenic transformation. Contemporary high-throughput mutational analyses have discovered recurrent gene mutations leading to activation of the JAK-STAT pathway, and mutations in other genes such as BCOR, DDX3X and TP53. The genomic landscape in ENKTCL highlights mechanisms of lymphomagenesis, such as immune response evasion, secondary to alterations in signaling pathways or epigenetics that directly or indirectly interfere with oncogenes or tumor suppressor genes. This overview discusses the most important findings of EBV pathogenesis and genetics in ENKTCL.

APOBECs and Herpesviruses

The apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like (APOBEC) family of DNA cytosine deaminases provides a broad and overlapping defense against viral infections. Successful viral pathogens, by definition, have evolved strategies to escape restriction by the APOBEC enzymes of their hosts. HIV-1 and related retroviruses are thought to be the predominant natural substrates of APOBEC enzymes due to obligate single-stranded (ss)DNA replication intermediates, abundant evidence for cDNA strand C-to-U editing (genomic strand G-to-A hypermutation), and a potent APOBEC degradation mechanism. In contrast, much lower mutation rates are observed in double-stranded DNA herpesviruses and the evidence for APOBEC mutation has been less compelling. However, recent work has revealed that Epstein-Barr virus (EBV), Kaposi’s sarcoma-associated herpesvirus (KSHV), and herpes simplex virus-1 (HSV-1) are potential substrates for cellular APOBEC enzymes. To prevent APOBEC-mediated restriction these viruses have repurposed their ribonucleotide reductase (RNR) large subunits to directly bind, inhibit, and relocalize at least two distinct APOBEC enzymes—APOBEC3B and APOBEC3A. The importance of this interaction is evidenced by genetic inactivation of the EBV RNR (BORF2), which results in lower viral infectivity and higher levels of C/G-to-T/A hypermutation. This RNR-mediated mechanism therefore likely functions to protect lytic phase viral DNA replication intermediates from APOBEC-catalyzed DNA C-to-U deamination. The RNR-APOBEC interaction defines a new pathogen-host conflict that the virus must win in real-time for transmission and pathogenesis. However, partial losses over evolutionary time may also benefit the virus by providing mutational fuel for adaptation.

The Clinical Features and Survival Outcome of 107 Newly Diagnosed Advanced Stage Extranodal NK/T-Cell Lymphoma Cases: A Triple-Center Study

Objective

Advanced stage extranodal natural killer/T-cell lymphoma (ENKTL) is a distinct type of non-Hodgkin lymphoma and the prognosis of ENKTL is poor with current treatment. This study aimed to investigate the clinical features, treatment strategy and survival outcome in patients with advanced stage ENKTL.

Patients and Methods

A total of 107 patients with newly diagnosed advanced stage ENKTL between January 2010 and December 2014 were reviewed from three cancer centers. Survival probability was calculated using Kaplan-Meier and the survival curves were compared by Log rank test. Cox regression analyses was performed to investigate the prognostic factors in ENKTL.

Results

The median patient age in our cohort was 42.0 years, with a male to female ratio of around 2.3:1. Over half of the patients had B symptoms (n = 61), high IPI scores (≥ 2, n = 60) and high Prognostic Index of Natural Killer Lymphoma (PINK) scores (≥ 3, n = 69). Elevated LDH level was present in around half of the patients (44/91). Most patients (n = 88) in our cohort originated in upper aerodigestive tract and the remaining 19 cases presented with non-upper aerodigestive tract involvement at first diagnosis. Chemotherapy regimens used in our study mainly include CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) (n = 26), L-asparaginase (L-asp) containing chemotherapy (GELOXD (gemcitabine, l-asparaginase, oxaliplatin and dexamethasone) and SMILE (L-asparaginase, methotrexate, ifosfamide, etoposide, and dexamethasone)) (n = 66). No significant difference between the baseline clinical characteristics was found between the L-asp and CHOP group. The CR rate after treatment was 39.3% (42/107) for the whole cohort. The 3-year progression-free survival (PFS) and 3-year overall survival (OS) rate was 41.0% and 41.5%, respectively. The 3-year PFS (49.2% vs 26.5%, P = 0.048) and 3-year OS (49.4% vs 26.0%, P = 0.030) was significantly higher in the L-asp group than the CHOP group. Patient CR status and PINK score were proved to be significant independent factors affecting OS and PFS by multivariate analysis. The grade 3/4 hematologic toxicity (P = 0.0003) and non-hematologic toxicity (P = 0.0002) occurred more frequently in the SMILE group than the GELOXD group.

Conclusion

Our results demonstrated that L-asp containing chemotherapy could provide favorable survival outcomes in patients with advanced stage ENKTL.

Extranodal NK/T cell lymphoma

Extranodal natural killer (NK)/T cell lymphoma (ENKTL) is a distinct subtype of Non-Hodgkin’s lymphoma mainly involving the nasal area. Since the entity was first recognized, treatment strategies have been evolving from anthracycline-based chemotherapy and radiotherapy to L-asparaginase containing regimens and recently immune checkpoint inhibitors. With the currently used combined chemotherapy and radiotherapy, more than 70% of patients with localized disease can be cured. L-asparaginase containing regimens have significantly improved treatment outcomes among patients with advanced disease. However, the treatment outcomes of patients with disease refractory to L-asparaginase containing regimens or who experience recurrence remain poor. In this article, we cover the current treatments for ENKTL and emerging treatment approaches.

Linking Environmental Exposures to Molecular Pathogenesis in Non-Hodgkin Lymphoma Subtypes

Non-Hodgkin lymphoma comprises a heterogeneous group of hematologic malignancies, with about 60 subtypes that arise via various pathogenetic mechanisms. Although establishing etiology for specific NHL subtypes has been historically difficult given their relative rarity, environmental exposures have been repeatedly implicated as risk factors across many subtypes. Large-scale epidemiologic investigations have pinpointed chemical exposures in particular, but causality has not been established, and the exact biologic mechanisms underpinning these associations are unclear. Here we review chemical exposures that have been associated with development of NHL subtypes and discuss their biologic plausibility based on current research.

Extranodal NK/T Cell Lymphoma, Nasal Type with Palatal Involvement: A Rare Case Report and Literature Review

T-cell lymphomas are infrequently encountered in the head and neck area, with the most common subtype being Extranodal NK/T cell lymphoma, nasal type (ENKTL-NT). ENKTL-NT shows a predilection for midline facial structures presenting with ulcerative destructive lesions, whereas palatal involvement is one of the most prominent signs from the oral cavity. Herein, we describe a case of a 76-year-old Greek man with nasal obstruction and an extensive painful necrotic ulcer with ragged borders on the left distal portion of the soft palate and palatine tonsil of 4-months duration. After an initial non-diagnostic biopsy from the nasopharynx, a second incisional biopsy from the palatal lesions was performed. Histopathology was suggestive of an angiocentric lymphoproliferative neoplasm and immunohistochemical examination and in situ hybridization for EBV RNA led to a final diagnosis of ENKTL-NT. The patient was placed under combined chemotherapy and radiotherapy and no recurrence has been noted. Additionally, a retrospective review of the cases in the English literature with an established diagnosis of ENTKL-NT between 2000 and 2019, based on the latest WHO classification of Head and Neck tumors, is performed.

Nasal NK/T cell lymphoma mimicking mucosa-associated lymphoid tissue lymphoma in morphology: A case report

The objective of the present study was to describe the clinicopathological features of a patient with nasal NK/T cell lymphoma that was similar in morphology to mucosa-associated lymphoid tissue lymphoma (MALToma). The clinicopathological data of a patient diagnosed with nasal NK/T cell lymphoma mimicking MALToma was collected, and the clinicopathological characteristics were discussed. The female patient was 43 years old and had suffered from persistent congestion for ten days. The mucosa in the left nasal cavity was inflamed, resulting in congestion and it was also purulent on the surface, as observed by nasal endoscopy. The disease was considered to be inflammatory based on CT scan. A biopsy after operation showed that the tumor consisted of small lymphoid cells that resembled MALToma in morphology. On the basis of the immunohistochemistry and in situ hybridization laboratory tests, a diagnosis of left nasal NK/T cell lymphoma was made. The patient received chemotherapy and radiotherapy, and remission was achieved six months after diagnosis. The patient was in a good condition at 16 months follow-up. In conclusion, NK/T cell lymphoma composed of small cells may be a type of indolent lymphoma with special characteristics of clinical presentation, image, pathology and prognosis. This case highlights that more attention is required by radiologists, pathologists and hematologists to diagnose this type of lymphoma.

The factors associated with the early diagnosis of nasal NK/T-cell lymphoma with prominent ocular symptoms and general nasal NKTL

AIM

This study explored the clinical features of nasal natural killer/T-cell lymphoma (NKTL) in patients with prominent ocular symptoms and those with general nasal NKTL to improve the early diagnosis of nasal NKTL.

METHOD

A retrospective cohort study was performed with 278 patients with nasal NKTL admitted to the First Affiliated Hospital of Zhengzhou University between January 2011 and December 2017. Of these cases, 56 presented with nasal NKTL and prominent ocular symptoms, and 222 presented with general nasal NKTL.

RESULTS

No significant differences in gender and age distribution were found between patients with general nasal NKTL and those with nasal NKTL and prominent ocular symptoms (p > 0.05). Cases of nasal NKTL and prominent ocular symptoms were usually complicated with B symptoms(48.2% vs 32.9%, p < 0.05). Patients with nasal NKTL and prominent ocular symptoms were more likely to progress to stage III disease (p < 0.01). The median time from first onset to diagnosis was 2.5 months. Most patients with general nasal NKTL had a longer history (69.6% vs 45.0%, p < 0.01). The misdiagnosis rate of the first visit of patients with general nasal NKTL was 29.3%, and that of patients with prominent ocular symptoms was 51.8%; this difference was significant (p < 0.01). Patients with nasal NKTL and prominent ocular symptoms showed a higher positive rate of EBV DNA (p < 0.01), which was significantly associated with staging (p < 0.01).

CONCLUSIONS

Compared with patients with general nasal NKTL, the early diagnosis of patients with prominent ocular symptoms is difficult and easy to misdiagnose. Patients with nasal NKTL and prominent ocular symptoms mostly present with advanced disease stages, and most patients have B symptoms and a high positive rate of EBV DNA.

Pathogenesis and biomarkers of natural killer T cell lymphoma (NKTL)

Natural killer T cell lymphoma (NKTL) is an aggressive disease with very poor treatment outcomes in the advanced stages. With chemotherapy, initial response rates to treatment are high but responses are short lived. A better understanding of the complex molecular pathogenesis of this disease is essential in order to design and develop better therapeutics with improved efficacy. This review aims to summarise the key pathogenic mechanisms in NKTL which may have significant prognostic and therapeutic implications.

Prognostic indicators of survival in sinonasal extranodal natural killer/T-cell lymphoma

OBJECTIVES

Extranodal natural killer/T-cell lymphoma (ENKTL) is a highly aggressive tumor of the sinonasal tract associated with poor overall survival (OS). This study expands upon epidemiologic, prognostic, and treatment factors for OS and disease-specific survival (DSS), incorporating newly accessible chemotherapy data.

METHODS

Retrospective population-based cohort study performed on cases of sinonasal ENKTL identified through the Surveillance, Epidemiology, and End Results database. Univariate Kaplan-Meier analysis and subsequent multivariate Cox-regression analysis were performed to evaluate prognostic and treatment variables for OS and DSS.

RESULTS

Four hundred and sixty cases of sinonasal ENKTL were identified. Five-year OS and DSS were 46% and 56%, respectively. On multivariate analysis, higher Ann Arbor stage was associated with worse OS (P < 0.001) and DSS (P < 0.001), whereas administration of radiotherapy was associated with improved OS (P < 0.001) and DSS (P = 0.001). Additionally, a higher age at diagnosis was associated with reduced OS (P = 0.024). Chemotherapy was associated with improved OS (P < .01) and DSS (P = .04) for Ann Arbor stage I disease. Surgery was not associated with improved survival.

CONCLUSION

This represents the first study to investigate the use of chemotherapy for the treatment of sinonasal ENKTL using population-based analysis. Radiation therapy and chemotherapy significantly improve survival in all Ann Arbor stage patients and early-stage patients, respectively. Early-stage disease is significantly associated with improved survival. With no established treatment regimen for sinonasal ENKTL, these findings suggest combination chemoradiation is an effective therapy for prolonged survival, especially in early stages of disease.

LEVEL OF EVIDENCE

3 Laryngoscope, 129:2675-2680, 2019.

Extranodal Natural Killer/T-Cell Lymphoma, Nasal Type: Basic Science and Clinical Progress

Extranodal natural killer (NK)/T-cell lymphoma, nasal type (NNKTL) has very unique epidemiological, etiologic, histologic, and clinical characteristics. It is commonly observed in Eastern Asia, but quite rare in the United States and Europe. The progressive necrotic lesions mainly in the nasal cavity, poor prognosis caused by rapid local progression with distant metastases, and angiocentric and polymorphous lymphoreticular infiltrates are the main clinical and histologic features. Phenotypic and genotypic studies revealed that the lymphoma is originated from either NK- or γδ T-cell, both of which express CD56. In 1990, the authors first reported the presence of Epstein-Barr virus (EBV)-DNA and EBV-oncogenic proteins, and EBV has now been recognized to play an etiological role in NNKTL. in vitro studies revealed that a wide variety of cytokines, chemokines, and micro RNAs, which may be produced by EBV-oncogenic proteins in the lymphoma cells, play important roles for tumor progression in NNKTL, and could be therapeutic targets. In addition, it was revealed that the interaction between NNKTL cells and immune cells such as monocytes and macrophages in NNKTL tissues contribute to lymphoma progression. For diagnosis, monitoring the clinical course and predicting prognosis, the measurements of EBV-DNAs and EBV-micro RNAs in sera are very useful. For treatment with early stage, novel concomitant chemoradiotherapy such as DeVIC regimen with local radiotherapy and MPVIC-P regimen using intra-arterial infusion developed with concomitant radiotherapy and the prognosis became noticeably better. However, the prognosis of patients with advanced stage was still poor. Establishment of novel treatments such as the usage of immune checkpoint inhibitor or peptide vaccine with molecular targeting therapy will be necessary. This review addresses recent advances in the molecular understanding of NNKTL to establish novel treatments, in addition to the epidemiologic, clinical, pathological, and EBV features.

Genomic and transcriptomic landscapes of Epstein-Barr virus in extranodal natural killer T-cell lymphoma

Extranodal natural killer T-cell lymphoma (nasal type; NKTCL) is an aggressive malignancy strongly associated with Epstein-Barr virus (EBV) infection. However, the role of EBV in NKTCL development is unclear, largely due to the lack of information about EBV genome and transcriptome in NKTCL. Here, using high-throughput sequencing, we obtained whole genome (n = 27) and transcriptome datasets (n = 18) of EBV derived from NKTCL tumor biopsies. We assembled 27 EBV genomes and detected an average of 1,152 single nucleotide variants and 44.8 indels (<50 bp) of EBV per sample. We also identified frequent focal EBV genome deletions and integrated EBV fragments in the host genome. Moreover, Phylogenetic analysis revealed that NKTCL-derived EBVs are closely clustered; transcriptome analysis revealed less activation of both latent and lytic genes and larger amount of T-cell epitope alterations in NKTCL, as compared with other EBV-associated cancers. Furthermore, we observed transcriptional defects of the BARTs miRNA by deletion, and the disruption of host NHEJ1 by integrated EBV fragment, implying novel pathogenic mechanisms of EBV. Taken together, we reported for the first time global mutational and transcriptional profiles of EBV in NKTCL clinical samples, revealing important somatic events of EBV and providing insights to better understanding of EBV’s contribution in tumorigenesis.

Specific Soft-Tissue Invasion and LMP1 Expression Are Potential Indicators of Extranodal NK/T Cell Lymphoma, Nasal Type

BACKGROUND Extranodal NK/T cell lymphoma, nasal type (ENKTL-NT) is difficult to distinguish from nasal polyps and inverted papilloma, leading to its high misdiagnosis ratio. The aim of this study was to investigate its potential prognostic indicators. MATERIAL AND METHODS Kaplan-Meier method was used to calculate overall survival (OS) rate. Cox proportional hazards regression was used to analyze risk ratios (ORs) with 95% confidence intervals (CIs). RESULTS Nasal ala infiltration and nasal floor thickness >2.0 mm or nasal septum thickness >2.5 mm were potential prognostic factors for OS (p=0.0323 and 0.0072, respectively). Cox proportional-hazards regression indicated that high LMP1 expression and the nasal floor thickness >2.0 mm or nasal septum thickness >2.5 mm were the independent risk factors for poor OS of ENKTL-NT (HR=3.0655, p=0.028; HR=2.3650, p=0.0452, respectively). In the subgroup analysis, the OS rate was lower when the nasal floor thickness >2.0 mm or nasal septum thickness >2.5 mm in the patients who had high expression of LMP1 (p=0.0651), whereas high LMP1 expression increased the risk of worse prognostic outcome in patients with deep infiltration thickness. Thus, high LMP1 expression may contribute to the tissue invasion of ENKTL-NT. CONCLUSIONS Any patient with nasal ala soft-tissue invasion, nasal floor thickness >2.0 mm/nasal septum thickness >2.5 mm on CT imaging or high LMP1 expression should prompt immediate histopathologic diagnosis to rule out ENKTL-NT in clinical practice.

Extranodal lymphomas in the public health system in Chile: Analysis of 1251 patients from the National Adult Cancer Program

The aim of the study was to describe the clinical and epidemiological characteristics, anatomic and histologic distribution, and treatment results of extranodal lymphomas (ENLs), diagnosed and treated in the public health system in Chile. We included patients with ENL diagnosed from 1998 to 2014, in 17 cancer centers, registered prospectively in the database of the National Adult Cancer Program (PANDA) of the Ministry of Health. Treatment was based on the local protocols for each lymphoma subtype. Extranodal lymphoma was documented in 1215 of 4907 non-Hodgkin lymphomas diagnosed in that period (25%). Median age was 59 years (range, 16-95), and 55% were female. The gastrointestinal (GI) tract was the most common location (38%), followed by the head and neck (24%) and the skin (15%). B-cell lymphomas accounted for 78% of cases, diffuse large B-cell lymphoma being the most common histologic subtype (68%). Mycosis fungoides/Sezary syndrome was the most frequent T-cell subtype (36%), followed by NK/T-cell lymphomanasal type (24%). In comparison with western countries, Chile showed a significantly high prevalence of NK/T-cell lymphoma nasal type, while the frequency of B-cell ENL and the anatomic distribution appeared similar, being GI the most commonly involved site.

Nasal NK/T-cell Lymphoma Presenting as Acute Inflammation of Nasal Vestibule

Extra nodal nasal NK/T cell lymphoma is relatively a rare type of non-Hodgkin lymphoma. Variable clinical presentation with rapidly progressive necrosis of the cartilaginous and bony wall of the nose and upper respiratory passages leads to delayed diagnosis and treatment. A 43-years-old patient presented with right nasal pain and furuncle-like swelling. The swelling progressed rapidly to cellulitis to the face up to the right eye. Within 2 months, it had advanced to necrosis of the lateral vestibular cartilage, medial maxillary wall, turbinate and nasal septal cartilage. Biopsy reported as non-Hodgkin diffuse T cell (angiocentric T cell) lymphoma.

Novel Immunotherapy Options for Extranodal NK/T-Cell Lymphoma

Extranodal NK/T-cell lymphoma (ENKTCL) is a highly aggressive mature NK/T-cell neoplasm marked by NK-cell phenotypic expression of CD3ε and CD56. While the disease is reported worldwide, there is a significant geographic variation with its highest incidence in East Asian countries possibly related to the frequent early childhood exposure of Epstein-Barr virus (EBV) and specific ethnic-genetical background, which contributes to the tumorigenesis. Historically, anthracycline-based chemotherapy such as CHOP (cyclophosphamide, adriamycin, vincristine, and prednisone) was used, but resulted in poor outcomes. This is due in part to intrinsic ENKTCL resistance to anthracycline caused by high expression levels of P-glycoprotein. The recent application of combined modality therapy with concurrent or sequential radiation therapy for early stage disease, along with non-anthracycline-based chemotherapy regimens consisting of drugs independent of P-glycoprotein have significantly improved clinical outcomes. Particularly, this neoplasm shows high sensitivity to l-asparaginase as NK-cells lack asparagine synthase activity. Even still, outcomes of patients with advanced stage disease or those with relapsed/recurrent disease are dismal with overall survival of generally a few months. Thus, novel therapies are needed for this population. Clinical activity of targeted antibodies along with antibody-drug conjugates, such as daratumumab (naked anti-CD38 antibody) and brentuximab vedotin (anti-CD30 antibody conjugated with auristatin E), have been reported. Further promising data have been shown with checkpoint inhibitors as high levels of programmed death-ligand 1 expression are observed in ENKTCL due to EBV-driven overexpression of the latent membrane proteins [latent membrane protein 1 (LMP1) and LMP2] with activation of the NF-κB/MAPK pathways. Initial case series with programmed death 1 inhibitors showed an overall response rate of 100% in seven relapsed patients including five with a complete response (CR). Furthermore, cellular immunotherapy with engineered cytotoxic T lymphocytes targeted against LMP1 and LMP2 have shown encouraging results with durable CRs as either maintenance therapy after initial induction chemotherapy or in the relapsed/refractory setting. In this paper, we review this exciting field of novel immunotherapy options against ENKTCL that hopefully will change the treatment paradigm in this deadly disease.

EBV in T-/NK-Cell Tumorigenesis

Epstein-Barr virus (EBV), which is associated with B-cell proliferative disorders, also transforms T- or natural killer (NK)-lineage cells and has been connected with various T- or NK (T/NK)-cell malignancies, such as extranodal NK/T-cell lymphoma-nasal type and aggressive NK-cell leukemia. Chronic active EBV (CAEBV) disease , which occurs most often in children and young adults in East Asia, is an EBV-associated T-/NK-cell lymphoproliferative disease. Patients with CAEBV often progress to overt lymphoma or leukemia over a long-term clinical course. EBV's transforming capacity in B cells is well characterized, but the molecular pathogenesis of clonal expansion caused by EBV in T/NK cells has not yet been clarified. In the primary infection, EBV infects B cells and epithelial cells and may also infect some T/NK cells. In some individuals, because of poor presentation by specific human leukocyte antigens or the genetic background, EBV-infected T/NK cells evade host immunity and survive. Occasionally, with the help of viral oncogenes, EBV-associated T/NK lymphoproliferative diseases, such as CAEBV, may develop. The subsequent accumulation of genetic mutations and/or epigenetic modifications in driver genes, such as DDX3X and TP53, may lead to overt lymphoma and leukemia. Activation-induced cytidine deaminase and the APOBEC3 family, driven by EBV infection, may induce chromosomal recombination and somatic mutations.

Overview of EBV-Associated T/NK-Cell Lymphoproliferative Diseases

Epstein-Barr virus-associated T/natural killer-cell lymphoproliferative diseases (EBV-T/NK-LPDs) are a group of rare diseases resulting from ectopic infection of T or natural killer (NK) lymphocytes with Epstein-Barr virus (EBV). EBV-T/NK-LPDs include chronic active EBV infection, EBV-associated hemophagocytic lymphohistiocytosis, hydroa vacciniforme-like lymphoproliferative disease, and severe mosquito bite allergy. Extra-nodal NK/T-cell lymphoma-nasal type and aggressive NK-cell leukemia can also be included in this broad spectrum. Currently, the etiology of EBV-T/NK-LPDs is unknown and no curative therapy has been established, except for hematopoietic stem cell transplantation. While most cases of EBV-T/NK-LPDs have been documented in specific areas of the world, they have also been documented more broadly across East Asia and Latin America. Consequently, active research and discussion of EBV-T/NK-LPDs are both necessary and important within the extensive international community of scientists and clinicians, to elucidate their etiology and develop a standard therapy.

Primary Pulmonary Extranodal Natural Killer/T-cell Lymphoma, Nasal Type Presenting as Diffuse Ground Glass Opacities: a Case Report

Extranodal natural killer (NK)/T-cell lymphoma, nasal type (ENKTCL) is a rare type of lymphoma that accounts for only 5%-18% of all cases of non-Hodgkin lymphoma (NHL). In published series, 60%-90% of NK/T-cell lymphomas are localized to the nasal and upper airway. We describe a 55-year man who presented with cough, sputum, dyspnea on exertion, and a chest computed tomography scan shows diffuse ground glass opacities (GGOs), suggestive of an interstitial lung disease. He was treated with a corticosteroid and his symptoms improved. However, when the corticosteroid was tapered, his symptoms recurred. The patient underwent a surgical lung biopsy and ENKTCL was diagnosed. We present this case because ENKTCL involving only the lung is very rare but very informative. To our knowledge, our patient is the first case that primary pulmonary ENKTCL is presented with GGOs.

Whole transcriptome analysis reveals dysregulated oncogenic lncRNAs in natural killer/T-cell lymphoma and establishes MIR155HG as a target of PRDM1

Natural killer/T-cell lymphoma is a rare but aggressive neoplasm with poor prognosis. Despite previous reports that showed potential tumor suppressors, such as PRDM1 or oncogenes associated with the etiology of this malignancy, the role of long non-coding RNAs in natural killer/T-cell lymphoma pathobiology has not been addressed to date. Here, we aim to identify cancer-associated dysregulated long non-coding RNAs and signaling pathways or biological processes associated with these long non-coding RNAs in natural killer/T-cell lymphoma cases and to identify the long non-coding RNAs transcriptionally regulated by PRDM1. RNA-Seq analysis revealed 166 and 66 long non-coding RNAs to be significantly overexpressed or underexpressed, respectively, in natural killer/T-cell lymphoma cases compared with resting or activated normal natural killer cells. Novel long non-coding RNAs as well as the cancer-associated ones such as SNHG5, ZFAS1, or MIR155HG were dysregulated. Interestingly, antisense transcripts of many growth-regulating genes appeared to be transcriptionally deregulated. Expression of ZFAS1, which is upregulated in natural killer/T-cell lymphoma cases, showed association with growth-regulating pathways such as stabilization of P53, regulation of apoptosis, cell cycle, or nuclear factor-kappa B signaling in normal and neoplastic natural killer cell samples. Consistent with the tumor suppressive role of PRDM1, we identified MIR155HG and TERC to be transcriptionally downregulated by PRDM1 in two PRDM1-null NK-cell lines when it is ectopically expressed. In conclusion, this is the first study that identified long non-coding RNAs whose expression is dysregulated in natural killer/T-cell lymphoma cases. These findings suggest that ZFAS1 and other dysregulated long non-coding RNAs may be involved in natural killer/T-cell lymphoma pathobiology through regulation of cancer-related genes, and loss-of-PRDM1 expression in natural killer/T-cell lymphomas may contribute to overexpression of MIR155HG; thereby promoting tumorigenesis.

Case of disseminated histoplasmosis in a HIV-infected patient revealed by nasal involvement with maxillary osteolysis

Background

Disseminated Histoplasmosis (DH) is a rare manifestation of Acquired Immune Deficiency Syndrome (AIDS) in European countries. Naso-maxillar osteolysis due to Histoplasma capsulatum var. capsulatum (Hcc) is unusual in endemic countries and has never been reported in European countries. Differential diagnoses such as malignant tumors, cocaine use, granulomatosis, vasculitis and infections are more frequently observed and could delay and/or bias the final diagnosis.

Case presentation

We report the case of an immunocompromised patient infected by Human Immunodeficiency Virus (HIV) with naso-maxillar histoplasmosis in a non-endemic country. Our aim is to describe the clinical presentation, the diagnostic and therapeutic issues. A 53-year-old woman, originated from Haiti, was admitted in 2016 for nasal deformation with alteration of general condition evolving for at least 6 months. HIV infection was diagnosed in 2006 and classified at AIDS stage in 2008 due to cytomegalovirus infection associated with pulmonary histoplasmosis. At admission, CD4 cell count was 9/mm³. Surgical biopsies were performed and ruled out differential or associated diagnoses. Mycological cultures identified Hcc and Blood Polymerase Chain Reaction (PCR) for Hcc was positive. The patient was given daily Amphothericin B liposomal infusion during 1 month. Hcc PCR became negative in the blood under treatment, and then oral switch by itraconazole was introduced. Antiretroviral treatment was reintroduced after a 3-week histoplasmosis treatment. Normalization of naso-maxillar mucosa enabled a palatal prosthesis.

Conclusion

Naso-maxillar histoplasmosis is extremely rare; this is the first case ever reported in a non-endemic country. Differential diagnoses must be ruled out by conducting microbiologic tools and histological examinations on surgical biopsies. Early antifungal treatment should be initiated in order to prevent DH severe outcomes.

Nasal NK/T Cell Lymphoma Presenting with Perforation of Palate: A Case Report and Review of Literature

Nasal Natural Killer (NK)/T cell lymphoma, commonly mentioned in the literature as Lethal Midline Granuloma (LMG) is an unusual pathology of the oro-maxillo-facial region characterized by aggressive and progressive destruction of the face, nose, palate and pharynx. This disease is now classified as a T-cell lymphoma based on modern cytogenetics, immunologic and molecular studies. However, it is mentioned in various literatures by various names. Here, we present one such clinically diagnosed, histopathologically and immunologically confirmed case of LMG, designated as NK/T cell lymphoma in a 56-year-old male. The uncommon presentation of NK/T cell lymphomas should be kept as a differential diagnosis for management of patients.

Intraocular Relapse with Hypopyon and Retinal Infiltrates after Chemotherapy and Peripheral Blood Stem Cell Transplantation for Extranodal NK/T-Cell Lymphoma

We report a case of intraocular relapse of extranodal NK/T-cell lymphoma with anterior chamber hypopyon and retinal infiltrates. A 55-year-old man developed fever, malaise, anorexia, and hepatosplenomegaly, and was diagnosed with NK/T-cell lymphoma by liver biopsy. He underwent 2 courses of SMILE (dexamethasone, methotrexate, ifosfamide, L-asparaginase, and etoposide) chemotherapy, followed by myeloablative peripheral blood stem cell transplantation, donated by his brother. Two months later, he developed high-grade fever, hepatosplenomegaly, and peritoneal lymphadenopathy, and the relapse with hemophagocytic syndrome was diagnosed by bone marrow biopsy. He underwent 2 courses of SMILE salvage chemotherapy, followed by non-myeloablative peripheral blood stem cell transplantation, donated by his son. Two months later, he noticed blurred vision in both eyes. The right eye had aqueous cells and keratic precipitates, but no retinal lesions. The left eye had hypopyon in the anterior chamber with numerous aqueous cells, and retinal white infiltrates with retinal hemorrhages. The aqueous cells, obtained by anterior chamber paracentesis, were positive for CD3, CD56, and Epstein-Barr virus-encoded RNA, but negative for CD20 by immunocytochemical staining. Head magnetic resonance imaging demonstrated white matter lesions in the anterior to parietal lobes on the right side. The patient underwent intrathecal methotrexate injection and external beam radiation at 40 Gy, covering the entire brain and both eyes. The retinal lesions and hypopyon disappeared. Two months later, the patient died of renal failure, and autopsy demonstrated multi-organ involvement of lymphoma cells. In conclusion, we report a case of NK/T-cell lymphoma relapse with intraocular lesions, after combined chemotherapy and hematopoietic stem cell transplantation.

Hypermethylation of PRDM1/Blimp-1 promoter in extranodal NK/T-cell lymphoma, nasal type: an evidence of predominant role in its downregulation

The loss of PRDM1 expression is common in extranodal NK/T-cell lymphoma, nasal type (EN-NK/T-NT), but the role of promoter methylation in silencing PRDM1 expression remains unclear. Hence, we performed pyrosequencing analysis to evaluate the promoter methylation of PRDM1 gene in vivo and in vitro, to analyze the association between methylation and its expression, and to assess cellular effects of PRDM1 reexpression. The promoter hypermethylation of PRDM1 gene was detected in 11 of 25 EN-NK/T-NT cases (44.0%) and NK92 and NKL cells. The promoter hypermethylation of PRDM1 was significantly correlated with PRDM1 expression in vivo and in vitro, predominantly contributing to the loss of PRDM1 expression compared with genetic deletion and aberrant expression of miR-223 in EN-NK/T-NT. PRDM1 expression was significantly restored by demethylation treatment, which induced cell proliferation suppression, cell cycle arrest, and apoptosis increase. We also found that PRDM1 reexpression could downregulate the expression of Ets-1, T-bet, granzyme B, and c-myc. Our findings demonstrated that the promoter hypermethylation of PRDM1 harbored a predominant role in the downregulation of PRDM1 expression, significantly affecting the biological behavior of tumor cells in EN-NK/T-NT.

Genetic risk of extranodal natural killer T-cell lymphoma: a genome-wide association study

BACKGROUND

Extranodal natural killer T-cell lymphoma (NKTCL), nasal type, is a rare and aggressive malignancy that occurs predominantly in Asian and Latin American populations. Although Epstein-Barr virus infection is a known risk factor, other risk factors and the pathogenesis of NKTCL are not well understood. We aimed to identify common genetic variants affecting individual risk of NKTCL.

METHODS

We did a genome-wide association study of 189 patients with extranodal NKTCL, nasal type (WHO classification criteria; cases) and 957 controls from Guangdong province, southern China. We validated our findings in four independent case-control series, including 75 cases from Guangdong province and 296 controls from Hong Kong, 65 cases and 983 controls from Guangdong province, 125 cases and 1110 controls from Beijing (northern China), and 60 cases and 2476 controls from Singapore. We used imputation and conditional logistic regression analyses to fine-map the associations. We also did a meta-analysis of the replication series and of the entire dataset.

FINDINGS

Associations exceeding the genome-wide significance threshold (p<5 × 10(-8)) were seen at 51 single-nucleotide polymorphisms (SNPs) mapping to the class II MHC region on chromosome 6, with rs9277378 (located in HLA-DPB1) having the strongest association with NKTCL susceptibility (p=4·21 × 10(-19), odds ratio [OR] 1·84 [95% CI 1·61-2·11] in meta-analysis of entire dataset). Imputation-based fine-mapping across the class II MHC region suggests that four aminoacid residues (Gly84-Gly85-Pro86-Met87) in near-complete linkage disequilibrium at the edge of the peptide-binding groove of HLA-DPB1 could account for most of the association between the rs9277378*A risk allele and NKTCL susceptibility (OR 2·38, p value for haplotype 2·32 × 10(-14)). This association is distinct from MHC associations with Epstein-Barr virus infection.

INTERPRETATION

To our knowledge, this is the first time that a genetic variant conferring an NKTCL risk is noted at genome-wide significance. This finding underlines the importance of HLA-DP antigen presentation in the pathogenesis of NKTCL.

FUNDING

Top-Notch Young Talents Program of China, Special Support Program of Guangdong, Specialized Research Fund for the Doctoral Program of Higher Education (20110171120099), Program for New Century Excellent Talents in University (NCET-11-0529), National Medical Research Council of Singapore (TCR12DEC005), Tanoto Foundation Professorship in Medical Oncology, New Century Foundation Limited, Ling Foundation, Singapore National Cancer Centre Research Fund, and the US National Institutes of Health (1R01AR062886, 5U01GM092691-04, and 1R01AR063759-01A1).

Genetic alterations of JAK/STAT cascade and histone modification in extranodal NK/T-cell lymphoma nasal type

Extranodal NK/T-cell lymphoma nasal type (ENKL) is a rare type of non-Hodgkin lymphoma that more frequently occurs in East Asia and Latin America. Even though its molecular background has been discussed in the last few years, the current knowledge does not explain the disease pathogenesis in most cases of ENKL. Here, we performed multiple types of next-generation sequencing on 34 ENKL samples, including whole-exome sequencing (9 cancer tissues and 4 cancer cell lines), targeted sequencing (21 cancer tissues), and RNA sequencing (3 cancer tissues and 4 cancer cell lines). Mutations were found most frequently in 3 genes, STAT3, BCOR, and MLL2 (which were present in 9, 7, and 6 cancer samples, respectively), whereas there were only 2 cases of JAK3 mutation. In total, JAK/STAT pathway- and histone modification-related genes accounted for 55.9% and 38.2% of cancer samples, respectively, and their involvement in ENKL pathogenesis was also supported by gene expression analysis. In addition, we provided 177 genes upregulated only in cancer tissues, which appear to be linked with angiocentric and angiodestructive growth of ENKL. In this study, we propose several novel driver genes of ENKL, and show that these genes and their functional groups may be future therapeutic targets of this disease.

Clonal deleted latent membrane protein 1 variants of Epstein-Barr virus are predominant in European extranodal NK/T lymphomas and disappear during successful treatment

Extranodal natural killer/T-cell lymphomas (NK/TL), rare in Europe, are Epstein-Barr virus (EBV) associated lymphomas with poor outcomes. Here, we determined the virus type and analyzed the EBV latent membrane protein-1 (LMP1) gene sequence in NK/TL from French patients. Six clones of viral LMP1 were sequenced by Sanger technology in blood from 13 patients before treatment with an l-asparaginase based regimen and, for 8 of them, throughout the treatment. Blood LMP1 sequences from 21 patients without any known malignancy were tested as controls. EBV Type A was identified for 11/13 patients and for all controls. Before treatment, a clonal LMP1 gene containing a 30 bp deletion (del30) was found in 46.1% of NK/TL and only in 4.8% of controls. Treatment was less effective in these patients who died more rapidly than the others. Patients with a deleted strain evolving toward a wild-type strain during treatment reached complete remission. The LMP1 gene was sequenced by highly sensitive next-generation sequencing technology in five NK/TL nasopharyngeal biopsies, two of them originating from the previous patients. Del30 was present in 100% of the biopsies; two viruses at least coexisted in three biopsies. These results suggest that del30 may be associated with poor prognosis NK/TL and that strain evolution could be used as a potential marker to monitor treatment.

Diabetes, Epstein-Barr virus and extranodal natural killer/T-cell lymphoma in India: Unravelling the plausible nexus

The International Diabetes Federation Diabetes Atlas estimates a staggering 590 million people affected with diabetes mellitus (DM) within the next two decades globally, of which Type 2 DM will constitute more than 90%. The associated insulin resistance, hyperinsulinemia, and hyperglycemia pose a further significant risk for developing diverse malignant neoplasms. Diabetes and malignancy are multifactorial heterogeneous diseases. The immune dysfunction secondary to Type 2 diabetes also reactivates latent infections with high morbidity and mortality rates. Epstein-Barr virus (EBV), a ubiquitous human herpes virus-4, is an oncogenic virus; its recrudescence in the immunocompromised condition activates the expression of EBV latency genes, thus immortalizing the infected cell and giving rise to lymphomas and carcinomas. Extranodal natural killer/T-cell lymphoma (ENKTCL), common in South-East Asia and Latin America; is a belligerent type of non-Hodgkin lymphoma (NHL) almost invariably associated with EBV. An analysis of articles sourced from the PubMed database and Google Scholar web resource until February 2014, suggests an increasing incidence of NHL in Asia/India and of ENKTCL in India, over the last few decades. This article reviews the epidemiological evidence linking various neoplasms with Type 2 DM and prognosticates the emergence of ENKTCL as a common lymphoreticular malignancy secondary to Type 2 diabetes, in the Indian population in the next few decades.

Retrospective Study of Pegaspargase, Gemicitabine, Oxaliplatin and Dexamethasone (Peg-GemOD) as a First-Line Therapy for Advanced-Stage Extranodal NK/T Cell Lymphoma

This study was conducted to retrospectively investigate the efficacy and safety of pegaspargase, gemicitabine, oxaliplatin and dexamethasone (Peg-GemOD) combination chemotherapy as a first-line therapy for advanced-stage extranodal NK/T cell lymphoma (ENKTL). Eighteen patients with newly diagnosed stage III/IV ENKTL were subjected to 3-6 cycles of Peg-GemOD chemotherapy. After 3 cycles of therapy, the overall response rate was 67 % (12/18) with a complete response rate of 28 % (5/18) and a partial response rate of 39 % (7/18). The median overall survival (OS) and progression-free survival (PFS) time were 10 and 8.5 months respectively. For those responders, the median OS and PFS time were significantly better than those of non-responders (median OS, 15 vs. 10 months; P = 0.001 and median PFS, 15 vs. 7 months; P = 0.001). Furthermore, patients with low plasma EBV-DNA levels after induction chemotherapy had a remarkably longer OS and PFS time. The toxicity of Peg-GemOD regimen was acceptable.

The Genetic Deletion of 6q21 and PRDM1 and Clinical Implications in Extranodal NK/T Cell Lymphoma, Nasal Type

6q21 genetic deletion has been frequently detected in extranodal NK/T cell lymphoma, nasal type (EN-NK/T-NT), and PRDM1 is considered as candidate gene. However, direct detection of PRDM1 deletion has not been well documented. We investigated genetic alterations of 6q21 and PRDM1 in 43 cases of EN-NK/T-NT and cell lines by FISH. PRDM1 expression was evaluated by immunohistochemistry and Western blot. The correlation between genetic alteration and PRDM1 expression and the significance in clinic-pathologic were analyzed. Heterozygous deletion of 6q21 and/or PRDM1 was observed in 24 of 43 cases (55.81%) of EN-NK/T-NT including 16 cases (37.21%) for 6q21 deletion and 19 cases (44.19%) for PRDM1 deletion. Similarly, heterozygous codeletion of 6q21 and PRDM1 was identified in NK92 and NKL cells. The heterozygous deletion of 6q21 and/or PRDM1 was correlated with PRDM1 expression. However, genetic deletion of 6q21 and/or PRDM1 was not correlated with clinicopathological features of EN-NK/T-NT, while PRDM1 expression showed positive effect on the outcome of patients as those as disease site, B symptom, and clinical stage. Thus, heterozygous deletion of 6q21 and/or PRDM1 was frequently detected in EN-NK/T-NT and correlated with downregulation of PRDM1. But the prognostic role of genetic deletion needs to be further evaluated in larger cohort.

Genotypic analysis and latent membrane protein 1 expression of Epstein-Barr virus in extranodal NK/T-cell lymphoma from Northern Chinese patients

As the most common NK/T-cell lymphoma in Asian countries, extranodal NK/T-cell lymphoma, nasal type (ENKTL), has unique clinical features and a strong association with Epstein-Barr virus (EBV). In order to gain a preliminary understanding of the relationship between ENKTL and EBV, we performed genotypic analysis of EBV and investigated LMP1 expression in extranodal NK/T-cell lymphoma. Our study shows that ENKTL is an EBV-associated malignancy and that A, C and F are the predominant EBV genotypes in northern China. LMP1 expression is stronger in extranasal sites than nasal sites, and the expression level is strongly correlated to ENKTL and may play an important role in the development of ENKTL.