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

Primary extranodal NK/T cell lymphoma of stomach: A case report and review of literature

ABSTRACT

Extranodal Natural killer/T (NK/T) cell lymphoma nasal type is an aggressive non-Hodgkin lymphoma and has a constant association with Epstein-Barr virus (EBV) infection. Approximately more than 75% cases are located in upper aero-digestive tract, of which stomach is a very rare site. Very few cases of gastric extranodal NK/T cell lymphoma have been reported in the literature. A 22-year-old male patient presented with complaints of abdominal pain and hematemesis. Endoscopy showed a large ulcer in the stomach. Partial gastrectomy done and histopathology showed transmural infiltration by intermediate size atypical lymphoid cells which are immunopositive for CD3, CD56, TIA, EBV-encoded RNA (EBER) and negative for CD4, CD8, CD20. A diagnosis of extranodal NK/T cell lymphoma nasal type was made.

Appropriate timing to perform an interim 18F-FDG PET/CT in patients with nasal-type extranodal natural killer/T cell lymphoma

Interim 18F-FDG PET/CT (I-PET) has a role in response evaluation and treatment guidance in patients with nasal-type extranodal natural killer/T cell lymphoma (ENKTL). However, there was no agreement on the timing of I-PET performed, after chemotherapy or after chemoradiotherapy. We aimed to find the appropriate timing for I-PET by assessing the prognostic value of I-PET in response evaluation in ENKTL patients. Two hundred and twenty-seven ENKTL patients who had undergone I-PET were retrospectively included. All patients were grouped based on their therapeutic strategy received, chemotherapy or chemoradiotherapy. The Deauville 5-point score (DS) was used to interpret the I-PET images. The hazard ratio (HR) and C-index were used to measure the discriminatory and prognostic capacities of I-PET performed at different times. One hundred and six patients underwent the I-PET after chemotherapy (chemotherapy group), while I-PET was performed after chemoradiotherapy in 121 patients (chemoradiotherapy group). Eighty-seven patients were classified as metabolic remission (DS score of 1-3), while the other 140 were classified as non-metabolic remission (DS score of 4-5) according to the Deauville criteria. There were no significant survival differences between patients in metabolic remission and in non-metabolic remission in either progression-free survival (PFS, p = 0.406) or overall survival (OS, p = 0.350). In the chemotherapy group, patients in metabolic remission had significantly superior PFS than patients in non-metabolic remission (p = 0.012). For OS, a discriminative trend was also found on the survival curve between patients in metabolic remission and in non-metabolic remission (p = 0.082). In the chemoradiotherapy group, there was no significant difference in PFS (P = 0.185) or OS (P = 0.627) between patients in metabolic remission and in non-metabolic remission. I-PET after chemotherapy yields higher discriminative power and has the ability for prognostic prediction in nasal-type ENKTL patients. I-PET after radiochemotherapy has no prognostic value. Thus, the appropriate timing for I-PET is after chemotherapy but before radiotherapy for response evaluation in nasal-type ENKTL patients.

International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors

BACKGROUND

Sinonasal neoplasms, whether benign and malignant, pose a significant challenge to clinicians and represent a model area for multidisciplinary collaboration in order to optimize patient care. The International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors (ICSNT) aims to summarize the best available evidence and presents 48 thematic and histopathology-based topics spanning the field.

METHODS

In accordance with prior International Consensus Statement on Allergy and Rhinology documents, ICSNT assigned each topic as an Evidence-Based Review with Recommendations, Evidence-Based Review, and Literature Review based on the level of evidence. An international group of multidisciplinary author teams were assembled for the topic reviews using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses format, and completed sections underwent a thorough and iterative consensus-building process. The final document underwent rigorous synthesis and review prior to publication.

RESULTS

The ICSNT document consists of four major sections: general principles, benign neoplasms and lesions, malignant neoplasms, and quality of life and surveillance. It covers 48 conceptual and/or histopathology-based topics relevant to sinonasal neoplasms and masses. Topics with a high level of evidence provided specific recommendations, while other areas summarized the current state of evidence. A final section highlights research opportunities and future directions, contributing to advancing knowledge and community intervention.

CONCLUSION

As an embodiment of the multidisciplinary and collaborative model of care in sinonasal neoplasms and masses, ICSNT was designed as a comprehensive, international, and multidisciplinary collaborative endeavor. Its primary objective is to summarize the existing evidence in the field of sinonasal neoplasms and masses.

Extranodal natural killer/T cell lymphoma nasal type simulating osteoradionecrosis with metachronic B lymphoma in the pelvis: Case report

Extranodal Natural Killer/T Cell Lymphoma Nasal Type (EN-NK/T-CL-NT) is a non-Hodgkin extranodal lymphoma of unfavorable prognosis due to its aggressive nature. This neoplasm mainly affects the paranasal sinuses, nasopharynx, oropharynx, oral cavity, palate, and rarely intestinal, gastric and skin regions. 50-year-old female with a history of lymphoma in nasal and pelvic region. At four years of tumors-free, has facial asymmetry, accompanied by sub-palpebral, nasal and lip edema. Intraoral examination revealed a large ulceration suggestive of osteoradionecrosis. Gum biopsy shows Extranodal NK/T Cell Lymphoma Nasal Type (EN-NK/T-CL-NT). In this case we highlight the characteristics of EN-NK/T-CL-NT with a presentation of osteoradionecrosis-like. Unfortunately, the nature of this tumor led to the patient's death. Clinical follow-up of patients with cancer is imperative to mend and/or decrease treatment complications, as well as to identify second primary tumors or the spread of the underlying disease.

Primary Extranodal Nasal-Type Natural Killer/T-Cell Lymphoma of Lower Limb Muscles on 18 F-FDG PET/CT

ABSTRACT

Extranodal nasal-type natural killer/T-cell lymphoma may arise anywhere outside the lymph nodes, predominantly including the nasal cavity, nasopharynx, oropharynx, upper respiratory tract, gastrointestinal tract, skin, testes, and salivary glands, whereas primary tumor arising in muscle is rarely documented. We report FDG PET/CT findings of primary extranodal nasal-type natural killer/T-cell lymphoma in the muscles of the right lower limb in an 82-year-old man.

miR-142: A Master Regulator in Hematological Malignancies and Therapeutic Opportunities

MicroRNAs (miRNAs) are a type of non-coding RNA whose dysregulation is frequently associated with the onset and progression of human cancers. miR-142, an ultra-conserved miRNA with both active -3p and -5p mature strands and wide-ranging physiological targets, has been the subject of countless studies over the years. Due to its preferential expression in hematopoietic cells, miR-142 has been found to be associated with numerous types of lymphomas and leukemias. This review elucidates the multifaceted role of miR-142 in human physiology, its influence on hematopoiesis and hematopoietic cells, and its intriguing involvement in exosome-mediated miR-142 transport. Moreover, we offer a comprehensive exploration of the genetic and molecular landscape of the miR-142 genomic locus, highlighting its mutations and dysregulation within hematological malignancies. Finally, we discuss potential avenues for harnessing the therapeutic potential of miR-142 in the context of hematological malignancies.

The expression and clinical significance of PLK1/p-PLK1 protein in NK/T cell Lymphoma

AIMS

To investigate the expression of polo-like kinase 1 protein (PLK1) and its phosphorylation level (p-PLK1) in extranodal NK/T cell lymphoma (NKTCL) and their correlation with clinical characteristics and prognosis.

METHODS

We collected 40 cases of NKTCL (referred to as the experimental group), which received diagnoses at the First Affiliated Hospital of Zhengzhou University between January 2018 and October 2022. Concurrently, we assembled a control group, including 20 cases afflicted with nasopharyngeal mucosal lymphoid hyperplasia diseases during the same timeframe. We utilized immunohistochemical techniques to evaluate the levels of PLK1 and p-PLK1 expression in both the experimental and control groups. Subsequently, we conducted an analysis to identify disparities in their expression and explore their relationships with clinical characteristics and patient prognosis.

RESULTS

Among the 40 NKTCL patients, there were 27 males and 11 females, with a median age of 51 years (range 12-80 years). Compared to the control group, the tissue samples of NKTCL patients exhibited significantly elevated expression levels and active phosphorylation levels of PLK1 (P < 0.05). Correlation analysis of the immunohistochemical H score and Ki-67 positive rate of PLK1 and p-PLK1, revealed a significant positive correlation for both (P < 0.0001, each). No statistically significant differences were observed in the distribution of PLK1 and p-PLK1 expression in NKTCL patients with respect to gender, age, Ann Arbor stage, PINK-E score, B-symptoms, lactate dehydrogenase, β2-microglobulin, blood EBV-DNA, bone marrow invasion, and lymph node metastasis (p > 0.05). Grouping based on PLK1 and p-PLK1 immunohistochemical H-scores revealed that the high expression of PLK1 and p-PLK1 was associated with poor prognosis.

CONCLUSIONS

The expression levels and active phosphorylation levels of PLK1 were significantly increased in NK/T cell lymphoma, and patients with overexpression of PLK1 and p-PLK1 had a poorer prognosis.

Aggressive Biology of Extra-Nodal NK/T Cell Lymphoma: A Case Report

Extra-nodal NK/T cell lymphoma, nasal type (ENKTL) is a rare and aggressive non-Hodgkin lymphoma primarily seen in Asian and South American populations. Diagnosis involves methods like biopsy and molecular testing, with treatment typically combining systemic and radiation therapy. We present the rare case of a 62-year-old female who was diagnosed with localized ENKTL upon initial presentation of nasal congestion. She was started on radiation therapy and responded favorably at first, with decreased congestion and facial swelling. After five weeks of treatment, she developed significant dysphagia and anorexia, which was initially attributed to being a side effect of chemotherapy. After pausing radiation treatment, her condition worsened until she was hospitalized for obstructive jaundice. CT scans and biopsy confirmed metastasis of the cancer to her pancreas. Her condition rapidly declined until she was ultimately sent to hospice care.

Extranodal NK/T-Cell Lymphoma, Nasal Type, Extranasal and Ulcerative Blister Variant, Case Report

The extranodal natural killer (NK) T-cell lymphoma of nasal type is a form of lymphoma that falls within the WHO/EORTC 2018 classification of cutaneous T-cell lymphomas. It is characterized for being aggressive, infrequent, and destroying midline facial structures; however, it can also be in primary or secondary form at extranasal sites, such as the skin or the gastrointestinal tract, among others. We report the case of an 18-year-old patient with an extranodal NK/T-cell lymphoma located in an extranasal site. The clinical presentation is characterized for being multifocal and with erythematous-violaceous plaques that progress to hemorrhagic blisters and necrotic ulcers. Although this type of lymphoma has been reported previously by others, the presence of blisters is an atypical finding, which we believe has been described only in one case in the medical literature.

CAR-T cells targeting CD38 and LMP1 exhibit robust antitumour activity against NK/T cell lymphoma

BACKGROUND

Natural killer/T cell lymphoma (NKTCL) is an aggressive lymphoma with a poor prognosis. Chimeric antigen receptor-transduced T (CAR-T) cell therapy has become a promising immunotherapeutic strategy against haematologic malignancies.

METHODS

In this study, four CAR-T cell lines (CD38-CAR, LMP1-CAR, CD38-LMP1 tandem CAR 1 and CD38-LMP1 tandem CAR 2) were generated. The effect of CAR-T cells against NKTCL cells was evaluated both in vitro and in vivo. Expression of T cell activation markers and cytokines produced by CAR-T cells were detected by flow cytometry.

RESULTS

The four CAR-T cell lines could effectively eliminate malignant NKTCL cells. They could be activated and produce inflammatory cytokines in a target-dependent manner. In vivo tests showed that the CAR-T cells exhibited significant antitumour effects in a xenotransplanted NKTCL mouse model.

CONCLUSIONS

In summary, four CAR-T cell lines exhibited significant cytotoxicity against NKTCL cells both in vitro and in vivo. These results indicated the effective therapeutic promise of CD38 and LMP1 CAR-T cells in NKTCL.

NK/T-cell Lymphoma With Orbital Involvement: A Case Report and Systematic Review of the Literature

PURPOSE

To present the clinical course of a patient with recurrent NK/T-cell lymphoma (NKTL) involving the orbit and to review the literature on patients with NKTL involving the orbit.

METHODS

The PubMed database was searched for all cases of NKTL involving orbital, intraocular, or adnexal ocular structures.

RESULTS

Ninety-six patients were included in the final analysis. The mean age of diagnosis was 48.1 ± 16.8 years. The patients were 53/96 (55.2%) male and 43/96 (44.8%) female. Tumor location varied and included the orbit in 80/96 (83.3%), nasosinus in 56/96 (58.3%), uvea in 11/96 (11.5%), lacrimal gland in 9/96 (9.4%), lacrimal drainage system in 11/96 (11.5%), and conjunctiva in 7/96 (7.3%) cases. Management included surgical debulking in 29/96 (30.2%) cases, radiotherapy in 52/96 (54.2%) cases, and chemotherapy in 82/96 (85.4%) cases. Median survival was 6 months (95% CI: 5-9). Chemotherapy (hazard ratio = 0.80, 95% CI: 0.67-0.95, p = 0.013), radiotherapy (hazard ratio = 0.75, 95% CI: 0.64-0.87, p < 0.001), and orbital involvement being a recurrence of disease (hazard ratio = 0.79, 95% CI: 0.67-0.95, p = 0.009) were associated with improved survival. Advanced Ann Arbor stage (III-IV) at diagnosis (hazard ratio = 1.22, 95% CI: 1.08-1.38, p = 0.001), vision loss (hazard ratio = 1.18, 95% CI: 1.04-1.34, p = 0.009), proptosis (hazard ratio = 1.15, 95% CI: 1.01-1.30, p = 0.035) and periorbital swelling (hazard ratio = 1.15, 95% CI: 1.00-1.33, p = 0.048) were associated with poor survival.

CONCLUSIONS

NK/T-cell lymphoma involving the orbit, globe, or ocular adnexa heralds a poor prognosis where early diagnosis and therapy are critical. The use of radiotherapy and chemotherapy is associated with improved survival.

Long-term survival by surgery and adjuvant chemotherapy in a patient with perforated extranodal NK/T-cell lymphoma of the small intestine: a retrospective case study

BACKGROUND

Extranodal natural killer/T-cell lymphoma, nasal type (ENKL) of the small intestine, is a disease with extremely poor prognosis. We describe treatment in a case which is novel in that it demonstrated long-term survival.

CASE PRESENTATION

A 68-year-old man was admitted to the emergency department of our hospital with the complaint of severe umbilical pain with tenderness and muscular defense. An abdominal computed tomography scan revealed a thick-wall mass on the small intestine and intra-abdominal free air. He was suspected of perforation of a small intestinal tumor and underwent emergency surgery. The surgery revealed a perforated tumor ulcer, and ENKL was diagnosed from the postoperative pathological findings. The patient's postoperative course was uneventful. He was further treated with adjuvant chemotherapy by hematologist comprising six courses of dexamethasone, etoposide, ifosfamide, and carboplatin. The patient demonstrated long-term survival and was in remission at the time of writing, four years and five months after surgery.

CONCLUSIONS

We report a rare case of long-term survival of perforated ENKL of the small intestine achieved by surgery and adjuvant chemotherapy with dexamethasone, etoposide, ifosfamide, and carboplatin. It is essential to consult with a hematologist to determine the most appropriate chemotherapy such as DeVIC if one encounters rare postoperative pathological findings of ENKL. To elucidate the pathophysiology of this disease and to prolong survival of affected patients, accumulation of cases of long-term survival and examination of associated characteristics is necessary.

Sugemalimab Monotherapy for Patients With Relapsed or Refractory Extranodal Natural Killer/T-Cell Lymphoma (GEMSTONE-201): Results From a Single-Arm, Multicenter, Phase II Study

PURPOSE

Relapsed or refractory extranodal natural killer/T-cell lymphoma (R/R ENKTL) is a rare and aggressive type of non-Hodgkin lymphoma with limited treatment options. This phase II study evaluated the efficacy and safety of sugemalimab, an anti-PD-L1 monoclonal antibody, in R/R ENKTL.

METHODS

Eligible patients received sugemalimab 1,200 mg intravenously once every 3 weeks for up to 24 months or until progression, death, or study withdrawal. The primary end point was objective response rate (ORR) assessed by an independent radiologic review committee. Key secondary end points included ORR assessed by the investigators, complete response rate, duration of response, and safety.

RESULTS

At the data cutoff (February 23, 2022), 80 patients were enrolled and followed for a median of 18.7 months. At baseline, 54 (67.5%) had stage IV disease and 39 (48.8%) had received ≥2 lines of prior systemic therapy. Independent radiologic review committee-assessed ORR was 44.9% (95% CI, 33.6 to 56.6); 28 (35.9%) patients achieved a complete response and seven (9.0%) achieved a partial response, with a 12-month duration of response rate of 82.5% (95% CI, 62.0 to 92.6). Investigator-assessed ORR was 45.6% (95% CI, 34.3 to 57.2), and 24 (30.4%) patients achieved a complete response. Most treatment-emergent adverse events were grade 1-2 in severity, and grade ≥ 3 events were reported in 32 (40.0%) patients.

CONCLUSION

Sugemalimab showed robust and durable antitumor activity in R/R ENKTL. Treatment was well tolerated with expected safety profile for this drug class.

Vesicular Lymphomatoid Papulosis With DUSP22-IRF4 Rearrangement on Chromosome 6p25.3: A Case Report

ABSTRACT

Lymphomatoid papulosis (LyP) with DUSP22-IRF4 rearrangement on chromosome 6p25.3 is a newly identified subtype of LyP. It is characterized by an older age of onset, localized skin lesions, with good prognosis, and it resembles a hybrid of LyP types B and C in histopathology. A limited number of cases have been reported so far. In this article, we reported a case of a 72-year-old man with recurrent episodes of widespread multiple discrete papular or vesicular eruptions on a region of the head, trunk, and 4 extremities for about 3 years. Histopathological examination of a vesicle revealed a subepidermal blister with abundant atypical lymphocytes in the vesicular space, band-like infiltrates in the papillary dermis, along with epidermotropism and pilosebaceous structure involvement. Fluorescence in situ hybridization analysis further demonstrated DUSP22-IRF4 rearrangement on chromosome 6p25.3. A diagnosis of vesicular LyP with this rare subtype was made according to the clinical and pathological findings.

Extranodal Natural Killer/T-cell Lymphoma Isolated to the Leg: A Case Report

Extranodal natural killer/T-cell lymphoma (ENKTL) is a subtype of non-Hodgkin's lymphoma, and it is exceedingly rare in North America. The "extranasal" subtype of ENKTL frequently involves the skin and typically has an aggressive course with no current standard of treatment available. In this report, we present a case of cutaneous ENKTL in an otherwise healthy middle-aged male.

A Case Report of Extranodal NK/T-Cell Lymphoma Misdiagnosed as Meibomitis

INTRODUCTION

Extranodal natural killer/T-cell lymphoma (ENKTL) is a rare type of non-Hodgkin's lymphoma. This report presents a patient with the right lower eyelid ENKTL misdiagnosed as meibomitis repeatedly.

CASE PRESENTATION

A 48-year-old woman developed recurrent redness and swelling in right eyelid for 2 years. Three eyelid mass removal operations were performed in local hospitals, and the pathological examination suggested meibomitis. Physical examination showed an induration in the lateral lower eyelid of the right eye, local defect of the eyelid margin, mild entropion, redness and swelling of the surrounding tissues, and temporal bulbar conjunctiva hyperemia. The eyelid lesion was resected and ENKTL was diagnosed by specific immunohistochemical staining and in situ hybridization. The lymphoma resolved with chemotherapy and radiotherapy. The patient was still alive forty-one months after the last operation.

CONCLUSION

Our report demonstrates that recurrent eyelid redness and swelling might be a malignant tumor, and clinicians should be vigilant.

Thirty Years of Experience With Ocular Adnexal T-Cell Lymphoma

PURPOSE

To evaluate the disease characteristics and survival of patients with ocular adnexal T-cell lymphoma.

METHODS

A retrospective, observational study of patients with a histopathological diagnosis of T-cell lymphoma of the ocular adnexa seen between 1992 and 2022. Demographic data, clinical presentation, imaging, histology, immunohistochemistry, treatment, and outcomes were reviewed.

RESULTS

Fifteen patients were included in the study with the mean age at diagnosis of 50 years old (range 7-85). The most common presenting symptoms were ulcerated eyelid skin lesions (40%) followed by eyelid swelling (13.3%), and lacrimal passageways obstruction (13.3%). The anaplastic large cell lymphoma (33%) and primary cutaneous T-cell lymphoma (33%) were the most diagnosed peripheral T-cell lymphoma subtypes, followed by the nasal type natural killer/T-cell lymphoma (27%) and peripheral T-cell lymphoma not otherwise specified (7%). The most prevalent stage of disease progression was stage I and stage IV (Ann Arbor classification) with seven (47%) patients each. Eight (53%) patients succumbed to the disease process of which three (37.5%) deceased in the first six months and six (75%) within the first year of diagnosis. We identified a strong statistical association between stage and disease-related death ( p = 0.003).

CONCLUSIONS

Peripheral T-cell lymphoma occurring in the orbit and ocular adnexa is extremely rare. Advanced stage at diagnosis leads to almost certain death from the disease despite aggressive local and systemic treatment. Early diagnosis improves the chances of survival but can be hindered by this condition's ability to simulate benign inflammatory conditions both clinically and histologically.

An Unusual Case of Extranodal Natural Killer/T-Cell Lymphoma, Nasal Type Masquerading as Dacryocystitis and Sinusitis

Extranodal natural killer (NK)/T-cell lymphoma, nasal type (NNKTL) is a rare and highly aggressive non-Hodgkin lymphoma originating from NK or γδ T cells infected by Epstein-Barr virus (EBV). In the United States, NNKTL is usually noted in people of Asian or Hispanic descent. Natural killer/T-cell lymphoma, nasal type commonly involves the upper aerodigestive tract, including the nasopharynx, nasal cavity, Waldeyer's ring, and oropharynx. Extensive local destruction and invasion has been noted, especially of the paranasal sinuses, hard palate, and central nervous system; involvement of the nasolacrimal duct with dacryocystitis is yet to be reported. We report a rare case of a Hispanic man with extranodal NNKTL masquerading as persistent dacryocystitis and necrotizing sinusitis unresponsive to antibiotics and surgical intervention. An extensive background of necrosis and inflammation was noted on pathology, and additional analysis with immunohistochemistry and in situ hybridization after repeat biopsy were necessary for accurate diagnosis.

Diagnostic performance and prognostic value of circulating tumor DNA methylation marker in extranodal natural killer/T cell lymphoma

Circulating tumor DNA (ctDNA) carries tumor-specific genetic and epigenetic variations. To identify extranodal natural killer/T cell lymphoma (ENKTL)-specific methylation markers and establish a diagnostic and prognosis prediction model for ENKTL, we describe the ENKTL-specific ctDNA methylation patterns by analyzing the methylation profiles of ENKTL plasma samples. We construct a diagnostic prediction model based on ctDNA methylation markers with both high specificity and sensitivity and close relevance to tumor staging and therapeutic response. Subsequently, we built a prognostic prediction model showing excellent performance, and its predictive accuracy is significantly better than the Ann Arbor staging and prognostic index of natural killer lymphoma (PINK) risk system. Notably, we further establish a PINK-C risk grading system to select individualized treatment for patients with different prognostic risks. In conclusion, these results suggest that ctDNA methylation markers are of great value in diagnosis, monitoring, and prognosis, which might have implications for clinical decision-making of patients with ENKTL.

Differential diagnosis of a local form of granulomatosis with polyangiitis: nasal cavity and paranasal sinuses lesions (part 1)

Granulomatosis with polyangiitis (GPA) is a primary vasculitis associated with antineutrophil cytoplasmic antibodies, characterized by necrotizing vasculitis with predominant involvement of small vessels of various localizations and necrotizing granulomatous inflammation with multiple clinical manifestations. GPA remains one of the most severe systemic vasculitis with unfavorable prognosis. When analyzing the course of the disease, there are two variants of GPA, local (with lesions of the upper respiratory tract, URT, organs of vision and hearing) and generalized (with lesions of the URT, organs of vision and hearing in combination with the lungs and/or kidneys, gastrointestinal tract, nervous systems, skin involvement).The article discusses the differential diagnosis of the disease with the nasal cavity and paranasal sinuses lesions onset, which requires an interdisciplinary approach and interaction of doctors of different specialties.

EBV dUTPase: A Novel Modulator of Inflammation and the Tumor Microenvironment in EBV-Associated Malignancies

There is increasing evidence that put into question the classical dogma that the Epstein-Barr virus (EBV) exists in cells as either a lytic virus in which new progeny is produced or in a latent state in which no progeny is produced. Notably, a third state has now been described, known as the abortive-lytic phase, which is characterized by the expression of some immediate early (IE) and early (E) genes, but no new virus progeny is produced. While the function of these IE and E gene products is not well understood, several recent studies support the concept they may contribute to tumor promotion by altering the tumor microenvironment (TME). The mechanisms by which these viral gene products may contribute to tumorigenesis remain unclear; however, it has been proposed that some of them promote cellular growth, immune evasion, and/or inhibit apoptosis. One of these EBV early gene products is the deoxyuridine triphosphate nucleotidohydrolase (dUTPase) encoded by BLLF3, which not only contributes to the establishment of latency through the production of activin A and IL-21, but it may also alter the TME, thus promoting oncogenesis.

Characteristics of Extranodal NK/T-Cell Lymphoma, Nasal Type, Compared with Nasal Diffuse Large B-cell Lymphoma

Background

Extranodal NK/T-cell lymphoma, nasal type (ENKL), is an aggressive tumour with poor prognosis. Its early diagnosis may improve the prognosis of patients; however, it is often overlooked in many cases and misdiagnosed as an inflammatory sinus disease during its initial stage. Identifying the clinical characteristics of ENKL may aid otorhinolaryngologists in indicating cases early for a pathologic examination. In this study, we aimed to investigate the clinical characteristics of ENKL compared with that of diffuse large B-cell lymphoma (DLBCL), which is the most common nasal malignant lymphoma.

Methods

The backgrounds, clinical symptoms, blood test results, and computed tomography images of patients with nasal/paranasal malignant lymphoma in our hospital between 2012 and 2017 were investigated. The characteristics of ENKL and nasal DLBCL were compared to differentiate them.

Results

A total of 27 patients with nasal cavity and/or paranasal sinus lymphoma were included. Extranodal NK/T-cell lymphoma, nasal type, was diagnosed in 10 patients, while DLBCL was diagnosed in 17 patients. The median age of patients with ENKL was significantly lower than that of patients with DLBCL. All patients with ENKL had a unilateral lesion in the nasal cavity, with most located at the inferior turbinate. They also experienced nasal symptoms with significantly higher incidence of nasal obstruction and tendency of bleeding.

Conclusion

ENKL was often unilateral and caused nasal obstruction, unlike DLBCL. Those who are younger in age and have sinonasal tumour with unilateral nasal obstruction and bleeding should be considered for early and repeated biopsies at multiple sites, with ENKL taken into consideration.

Narrow-band imaging for detecting nasal lymphoma

INTRODUCTION

Narrow-band imaging (NBI) is an advanced endoscopic technique that enhances the mucosal neovascularization. The utilization of narrow-band imaging on the detection of nasal lymphomas is not well-established.

AIM

To present a clinical case whose nasal lymphoma was detected with the aid of NBI.

CASE REPORT

A 91-year-old male presented to the ear, nose, and throat clinic with right persisting nasal obstruction for 4 months. NBI revealed a well demarcated lesion with an elongated vessel on the surface of the right inferior nasal turbinate. Histopathologic analysis of tissue specimen proved to be extranodal NK/T-cell lymphoma, nasal type.

CONCLUSIONS

NBI is useful for the detection of nasal lymphomas. NBI may be a valuable screening tool for nasal lymphomas as it is non-invasive and affordable.

Sinonasal lymphoma: A primer for otolaryngologists

Objective

Sinonasal lymphomas are a rare entity that commonly present with nonspecific sinonasal symptoms and are often recognized immediately. Through this review, we aim to summarize important principles in diagnosis and treatment of sinonasal lymphomas, with the goal of disseminating the current knowledge of this under-recognized malignancy to otolaryngologists.

Methods

Systemic review using PRISMA guidelines of foundational scholarly articles, guidelines, and trials were reviewed focusing on clinical characteristics of key sinonasal lymphoma subtypes, along with available treatments in the otolaryngology, medical oncology, and radiation oncology literature.

Results

Sinonasal lymphoma are derived from clonal proliferation of lymphocytes at various stages of differentiation, of which diffuse large B-cell lymphoma (DLBCL) and extranodal natural killer/T-cell lymphoma (ENKTL) are the most common. Diagnosis and staging require biopsy with immunohistochemistry in conjunction with imaging and laboratory studies. Treatment is ever evolving and currently includes multi-agent chemotherapy and/or radiation therapy.

Conclusion

Otolaryngologists may be the first to recognize sinonasal lymphoma, which requires a comprehensive workup and a multidisciplinary team for treatment. Symptoms are nonspecific and similar to many sinonasal pathologies, and it is crucial for otolaryngologists to keep a broad differential.

Level of Evidence

5.

Nasal-type extranodal natural killer/T-cell lymphoma with oral ulcer as the earliest clinical manifestation

Nasal-type extranodal natural killer/T-cell lymphoma (ENKTL-NT) is a special subtype of non-Hodgkin's lymphoma derived from natural killer cells or cytotoxic T cells. Oral ulcers as the first symptom makes its diagnosis challenging because of its rarity and lack of understanding. We report a case of ENKTL-NT in this paper. We analyzed the clinicopathological features, differential diagnosis, treatment, prognosis and the causes of misdiagnosis to provide a diagnostic basis for dentists to make better clinical diagnosis and treatment.

Cellular Origins and Pathogenesis of Gastrointestinal NK- and T-Cell Lymphoproliferative Disorders

The intestinal immune system, which must ensure appropriate immune responses to both pathogens and commensal microflora, comprises innate lymphoid cells and various T-cell subsets, including intra-epithelial lymphocytes (IELs). An example of innate lymphoid cells is natural killer cells, which may be classified into tissue-resident, CD56bright NK-cells that serve a regulatory function and more mature, circulating CD56dim NK-cells with effector cytolytic properties. CD56bright NK-cells in the gastrointestinal tract give rise to indolent NK-cell enteropathy and lymphomatoid gastropathy, as well as the aggressive extranodal NK/T cell lymphoma, the latter following activation by EBV infection and neoplastic transformation. Conventional CD4+ TCRαβ+ and CD8αβ+ TCRαβ+ T-cells are located in the lamina propria and the intraepithelial compartment of intestinal mucosa as type 'a' IELs. They are the putative cells of origin for CD4+ and CD8+ indolent T-cell lymphoproliferative disorders of the gastrointestinal tract and intestinal T-cell lymphoma, NOS. In addition to such conventional T-cells, there are non-conventional T-cells in the intra-epithelial compartment that express CD8αα and innate lymphoid cells that lack TCRs. The central feature of type 'b' IELs is the expression of CD8αα homodimers, seen in monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL), which primarily arises from both CD8αα+ TCRαβ+ and CD8αα+ TCRγδ+ IELs. EATL is the other epitheliotropic T-cell lymphoma in the GI tract, a subset of which arises from the expansion and reprograming of intracytoplasmic CD3+ innate lymphoid cells, driven by IL15 and mutations of the JAK-STAT pathway.

EBV+ lymphoproliferative diseases: opportunities for leveraging EBV as a therapeutic target

Epstein-Barr virus (EBV) is a ubiquitous human tumor virus, which contributes to the development of lymphoproliferative disease, most notably in patients with impaired immunity. EBV-associated lymphoproliferation is characterized by expression of latent EBV proteins and ranges in severity from a relatively benign proliferative response to aggressive malignant lymphomas. The presence of EBV can also serve as a unique target for directed therapies for the treatment of EBV lymphoproliferative diseases, including T cell-based immune therapies. In this review, we describe the EBV-associated lymphoproliferative diseases and particularly focus on the therapies that target EBV.

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.

Impact of Epstein-Barr Virus on Peripheral T-Cell Lymphoma Not Otherwise Specified and Angioimmunoblastic T-Cell Lymphoma

Purpose

The significance of Epstein-Barr virus (EBV) infections for the prognosis of patients with peripheral T-cell lymphomas (PTCLs), specifically angioimmunoblastic T-cell lymphoma (AITL) and PTCL not otherwise specified (PTCL-NOS), remains unclear. The Epstein-Barr encoding region can be used to detect EBV in tissue sections by in situ hybridization (ISH) and by polymerase chain reaction (PCR) assays of peripheral blood samples from patients with PTCLs. This study compared the outcomes patients with AITL or PTCL-NOS for whom the presence of EBV infection was assessed by these two methods.

Patients and Methods

This was a retrospective study of patients newly diagnosed with AITL or PTCL-NOS. All patients were selected from a single transplantation center. EBV-positive lymphomas were detected at the time of diagnosis in tissue sections by ISH or in the blood by PCR.

Results

Out of a cohort of 140 patients with histologically confirmed AITL or PTCL-NOS, 105 were EBV-positive. The 3-year overall survival of patients with EBV-positive TCL was 43.3% compared to 68.6% in patients with EBV-negative TCL (p = .01). Patients who were treated with autologous or allogeneic hematopoietic stem cell transplantation (n = 28 and n = 11, respectively) or chemotherapy alone (n = 66) had 3-year survival rates of 67.0%, 62.3%, and 30.2%, respectively (p <.02). Patients with EBV-positive TCL had a better prognosis after treatment with hematopoietic stem cell transplantation compared to chemotherapy alone, but no difference was seen among patients with EBV-negative TCL.

Conclusions

EBV infection was shown to negatively affect the clinical outcomes of patients with TCL. Stem cell transplantation has been found to be an effective treatment for EBV-associated lymphomas. Further investigations are warranted to determine the optimal treatment for these patients.

Successful Treatment of Primary CNS Extranodal NK/T-Cell Lymphoma with Surgery and Chemotherapy Combined with Sintilimab: A Case Report and Literature Review

Primary central nervous system extranodal natural killer/T-cell lymphoma (PCNS ENK/TCL) is an extremely rare lymphoma. Only 23 cases of PCNS ENK/TCL have been reported in the English literature. Due to the rarity of this lymphoma, an effective therapeutic strategy has not been defined. Generally, this type of lymphoma is treated with surgery, intrathecal chemotherapy, and postoperative chemoradiation therapy. The prognosis is poor. Herein, we present a case of primary brain NK/T cell lymphoma in a 50-year-old immunocompetent Chinese female and review the literature. The patient underwent intracranial tumor resection and was subsequently treated with a PD1 monoclonal antibody (Sintilimab) combined with chemotherapy. The patient survived 15 months after diagnosis. This is the first report of PCNS ENK/TCL treated with surgery and chemotherapy combined with immunotherapy and suggests an effective treatment regimen for PCNS ENK/TCL.

Skin diseases in Asian individuals that you do not want to miss: A selection of unique or relatively more common conditions in Asian populations

The Asian population currently constitutes a simple majority of the global population, comprising nearly 60%. The percentage of the US population that identifies as Asian is expected to grow to 41 million by the year 2050, making up an eventual 9% of the US population. As the world and US populations of Asian individuals increase, the demand for dermatologic care from this population will increase, requiring dermatologists to become more familiar with the diagnosis and treatment of Asian-specific skin characteristics and diseases. In this contribution, we review skin conditions specific to or relatively more common in Asian patients to help recognition and management of diseases in an increasing Asian patient population. We discuss prurigo pigmentosa, primary cutaneous plasmacytosis, lipodystrophia centrifugalis abdominalis infantilis, Epstein-Barr viru-positive T- and natural killer-cell lymphoproliferative disorders, acquired bilateral nevus of Ota-like macules, and Behҫet disease.

Sintilimab for relapsed/refractory extranodal NK/T cell lymphoma: a multicenter, single-arm, phase 2 trial (ORIENT-4)

This study (ORIENT-4) aimed to assess the efficacy and safety of sintilimab, a humanized anti-PD-1 antibody, in patients with relapsed/refractory extranodal NK/T cell lymphoma (r/r ENKTL). ORIENT-4 is a multicenter, single-arm, phase 2 clinical trial (NCT03228836). Patients with r/r ENKTL who failed to at least one asparaginase-based regimen were enrolled to receive sintilimab 200 mg intravenously every 3 weeks for up to 24 months. The primary endpoint was the objective response rate (ORR) based on Lugano 2014 criteria. Twenty-eight patients with r/r ENKTL were enrolled from August 31, 2017 to February 7, 2018. Twenty-one patients (75.0%, 95% CI: 55.1-89.3%) achieved an objective response. With a median follow-up of 30.4 months, the median overall survival (OS) was not reached. The 24-month OS rate was 78.6% (95% CI, 58.4-89.8%). Most treatment-related adverse events (TRAEs) were grade 1-2 (71.4%), and the most common TRAE was decreased lymphocyte count (42.9%). Serious adverse events (SAEs) occurred in 7 (25.0%) patients, and no patient died of adverse events. Sintilimab is effective and well tolerated in patients with r/r ENKTL and could be a novel therapeutic approach for the control of ENKTL in patients.

Suppression of latent transforming growth factor-β (TGF-β)-binding protein 1 (LTBP1) inhibits natural killer/ T cell lymphoma progression by inactivating the TGF-β/Smad and p38MAPK pathways

BACKGROUND

Natural killer/T cell lymphoma (NKTCL) is a distinct subtype of Non-Hodgkin's lymphoma with highly aggressive clinical behavior. We aim to investigate the function of Latent transforming growth factor β binding protein 1 (LTBP1) and transforming growth factor beta1 (TGF-β1) and complex molecular pathogenesis of this disease.

METHODS

NKTCL patients and reactive lymph nodes patients were recruited in this study. The expression of LTBP1 and TGF-β1 was examined using qRT-PCR, Western blot, IHC and ELISA analyses in biopsied tissues and serum from participants and NKTCL cell lines. Cell proliferation was determined using CFSE. Cell cycle and apoptosis were evaluated using flow cytometric analyses. The expression of Ki-67, CDK4 and cyclinD1 proteins was measured using Western blot analyses. The roles of LTBP-1/TGF-β1 in EMT program were determined by measuring E-cadherin, N-cadherin and Vimentin using Western blot analyses. The effects of LTBP-1 and TGF-β1 on tumor progression in vivo were determined by animal experiments.

RESULTS

LTBP-1 and TGF-β1 levels were elevated in NKTCL tissues and serum. The expression of LTBP-1 was positively correlated with the expression of TGF-β1 in NKTCL tissues. LTBP-1 was overexpressed in NKTCL cells. Knockdown of LTBP-1 suppressed cell proliferation and cell cycle progression, induced cell apoptosis, and suppressed EMT program in NKTCL cells. These effects of LTBP-1 knockdown were attenuated after TGF-β1 stimulation. Knockdown of LTBP-1 inhibited NKTCL tumor weight and volume in vivo. Also, stimulation of TGF-β1 attenuated the suppressive effects on tumor growth from sh-LTBP-1. Silencing of LTBP-1 lowered cellular TGF-β1, phosphorylated-Smad2, phosphorlyatd-Smad3, and phosphorylated-p38 and the suppressive effects were reversed after stimulation of TGF-β1.

CONCLUSION

Our findings suggested that inhibition of LTBP-1/TGF-β1 suppressed the malignant phenotypes of NKTCL cells and tumor growth via inactivating the canonical TGF-β/Smad signaling and p38^MAPK signaling.

Nasal-type T-cell lymphoma referred as fungal rhinosinusitis: Case report

NKTCL is a rare and destructive midline tumor that can be easily misdiagnosed as other more common inflammatory processes. The differential diagnosis of NKTCL should always be kept in mind for any lesion of the paranasal sinuses with atypical presentation and nonresponsive to conventional treatments.

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.

Mature T/NK-Cell lymphomas of the oral and maxillofacial region: A multi-institutional collaborative study

BACKGROUND

The diagnosis of oral and maxillofacial mature T/NK-cell neoplasms is challenging because of their rarity, morphological heterogeneity and complex immunophenotype with scarce available data describing their clinical and microscopic aspects. Therefore, in this study, we investigated a series of mature T/NK-cell neoplasms affecting this anatomical region and provided an updated literature review.

METHODS

Cases diagnosed as mature T/NK-cell lymphomas affecting the oral and maxillofacial region were retrospectively retrieved from six pathology files and their diagnoses were confirmed using haematoxylin and eosin-stained slides, immunohistochemical reactions and in situ hybridization for Epstein-Barr virus (EBV) detection. Patients' clinical data were collected from their pathology forms.

RESULTS

A total of 22 cases were included in this study. Eleven (50%) consisted of extranodal NK/T-cell lymphomas, nasal type; eight (36.4%) were peripheral T-cell lymphomas, NOS; two (9.1%) were adult T-cell leukaemia/lymphomas, and one (4.5%) was an ALK-positive anaplastic large cell lymphoma. Overall, males predominated, with a mean age of 55.7 years. The palate was the most affected site (50%), and tumours usually presented as destructive and painful ulcers. EBV was present in all cases of extranodal NK/T-cell lymphoma nasal type but was absent in the other subtypes.

CONCLUSION

Among mature T/NK-cell lymphomas of the oral and maxillofacial region, extranodal NK/T-cell lymphoma, nasal type and peripheral T-cell lymphoma, NOS predominated. Older men were the most affected patients, and this heterogeneous group of neoplasms has a very aggressive clinical behaviour.

Extranodal NK/T-Cell Lymphoma, Nasal Type: Genetic, Biologic, and Clinical Aspects with a Central Focus on Epstein-Barr Virus Relation

Extranodal NK/T-Cell Lymphoma, nasal type (ENKTL-NT) has some salient aspects. The lymphoma is commonly seen in Eastern Asia, has progressive necrotic lesions in the nasal cavity, makes midfacial destructive lesions, and shows poor prognosis. The lymphoma cell is originated from either NK- or γδ T-cells, which express CD56. Since the authors first demonstrated the existence of Epstein–Barr virus (EBV) DNA and EBV oncogenic proteins in lymphoma cells, ENKTL-NT has been recognized as an EBV-associated malignancy. Because the angiocentric and polymorphous lymphoma cells are mixed with inflammatory cells on a necrotic background, the diagnosis of ENKTL-NT requires CD56 immunostaining and EBER in situ hybridization. In addition, serum the EBV DNA level is useful for the diagnosis and monitoring of ENKTL-NT. Although ENKTL-NT is refractory lymphoma, the prognosis is improved by the development of therapies such as concomitant chemoradiotherapy. The basic research reveals that a wide variety of intracellular/cell surface molecules, cytokines, chemokines, and micro RNAs are involved in lymphomagenesis, and some of them are related to EBV. Understanding lymphoma behavior introduces new therapeutic strategies, such as the usage of immune checkpoint inhibitors, peptide vaccines, and molecular targeting therapy. This review addresses recent advances in basic and clinical aspects of ENKTL-NT, especially its relation to EBV features.

Activation of MEK1/2/Nrf-2 Signaling Pathway by Epstein-Barr Virus-Latent Membrane Protein 1 Enhances Autophagy and Cisplatin Resistance in T-Cell Lymphoma

Epstein-Barr virus-latent membrane protein 1 (EBV-LMP1) was associated with lymphoma, but its specific mechanism is still controversial. The study is aimed at studying the regulation of lymphoma resistance by EBV-LMP1 through the MEK1/2/Nrf-2 signaling pathway. First, LMP1 was knocked down in EBV-positive SNK-6 cells and overexpressed in EBV-negative KHYG-1 cells. First, we found that overexpression of LMP1 significantly promoted the resistance of KHYG-1 cells to cisplatin (DDP), which was related to increased autophagy in the cells. In contrast, knockdown of LMP1 expression in SNK-6 cells promoted cellular sensitivity to DDP and reduced the autophagy of cells after DDP treatment. Moreover, specific inhibition of autophagy in KHYG-1 cells significantly attenuated the resistance to DDP caused by overexpression of LMP1, but treatment with rapamycin in SNK-6 cells significantly promoted the autophagy in the cells. Subsequently, overexpression of LMP1 promoted the activation of the MEK1/2-Nrf2 pathway in KYHG-1 cells, whereas knockdown of LMP1 in SNK-6 cells inhibited the activation of the MEK1/2-Nrf2 pathway. Inhibition of MEK1/2/Nrf-2 blocked the promoting effects of LMP1 on lymphoma cell resistance. In conclusion, EBV-LMP1 promotes cell autophagy after DDP treatment by activating the MEK1/2/Nrf-2 signaling pathway in lymphoma cells, thus, enhancing the resistance of lymphoma cells to DDP.

Combination of Gemcitabine and Thymosin alpha 1 exhibit a better anti-tumor effect on nasal natural killer/T-cell lymphoma

BACKGROUND

Nasal natural killer/T-cell lymphoma (NNKTL) is an aggressive and poor prognostic malignant tumor along with high-level infection of Epstein-Barr virus (EBV). Gemcitabine (Gem) and Thymosin alpha 1 (Tα1) exert an anti-tumor effect in various cancers. However, the effect of the combination of Gem and Tα1 in NNKTL remains unknown.

METHODS

SNK6 cells were treated with Gem, Tα1 and Gem plus Tα1 for 48 h. The expression levels of EBV and inflammatory factors were measured by qRT-PCR assay. The effect of Gem and Tα1 on cell viability, proliferation, apoptosis, autophagy was detected by CCK-8, colony formation, flow cytometry, autophagic flux measurement, respectively. Western blot was used to evaluate the expression of proteins related to epithelial-mesenchymal transition (EMT), apoptosis and autophagy. In vivo xenograft models were used to further verify the roles of Gem and Tα1. Tumors were removed for weight measurement, H&E and IHC staining.

RESULTS

We identified that the half maximal inhibitory concentration (IC50) of Gem and Tα1 was 116.5 μmol/ml and 1.334 μmol/ml. Alone or combined administration of Gem and Tα1 dramatically attenuated the EBV viral load and promoted inflammatory factors expression in SNK6 cells, among which the combination of Gem and Tα1 treatment showed the most significant effect. Besides, combination treatment with Gem and Tα1 markedly inhibited cell growth and EMT progress, and enhanced apoptosis and autophagy. Similarly, Gem combined with Tα1 suppressed tumor growth, promoted apoptosis and autophagy in vivo. Additionally, combination treatment with Gem and Tα1 inhibited PI3K/AKT/mTOR pathway.

CONCLUSION

In summary, combination administration of Gem and Tα1 suppressed the progression of NNKTL in vivo and in vitro. Our study provided an effective therapeutic strategy potentially for the clinical treatment of NNKTL.

Extra-Nodal, Nasal, Natural Killer T-Cell Lymphoma Treated With a Checkpoint Inhibitor: A Case Report of a Sustained Complete Response

Extra-nodal natural killer T-cell lymphoma (ENKTL) is a rare and aggressive hematologic malignancy found in the nasal cavity and adjacent locations in 80% of cases, accounting for approximately 10% of non-Hodgkin lymphoma (NHL) and 0.4% of all cancers. Prognosis is typically poor and depends on stage, location, age, and tumor markers for targeted therapy, which is reserved for relapsed/refractory ENKTL. Of those, advanced clinical stage, higher Prognostic Index (PI), nodal involvement, Ki-67 expression, large cells, local tumor invasiveness, and circulating Epstein-Barr virus (EBV)-DNA levels are predictive of worse survival. Here, we present a rare case of a patient in remission 30 months after diagnosis of ENKTL following a sustained complete response to pembrolizumab, an immune checkpoint inhibitor targeting the programmed death-1 (PD-1) receptor.

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.

A composite single-nucleotide polymorphism prediction signature for extranodal natural killer/T-cell lymphoma

Current prognostic scoring systems based on clinicopathologic variables are inadequate in predicting the survival and treatment response of extranodal natural killer/T-cell lymphoma (ENKTL) patients undergoing non-anthracyline-based treatment. We aimed to construct a classifier based on single-nucleotide polymorphisms (SNPs) for improving predictive accuracy and guiding clinical decision-making. The data of 722 patients with ENKTL from international multicenters were analyzed. A 7-SNP-based classifier was constructed using LASSO Cox regression in the training cohort (n=336) and further validated in the internal testing (n=144) and two external validation cohorts (n=142; n=100). The 7-SNP-based classifier showed good prognostic predictive efficacy in the training cohort and the three validation cohorts. Patients with high and low risk scores calculated by the classifier exhibited significantly different progression-free survival (PFS) and overall survival (OS) (all p<0.001). The 7-SNP-based classifier was further proved to be an independent prognostic factor by multivariate analysis, and its predictive accuracy was significantly better than clinicopathological risk variables. The application of the 7-SNP-based classifier was not affected by sample types. Notably, chemotherapy combined with radiotherapy significnalty improved PFS and OS versus radiotherapy alone in high risk Ann Anbor stage I patients, while there was no statistical difference between the two therapeutic modalities among low risk patients. A nomogram was constructed comprised of the classifier and clinicopathological variables, and showed remarkably better predictive accuracy than that of each variable alone. The 7-SNP-based classifier is a complement to existing risk stratification systems in ENKTL, which could have significant implications for clinical decision-making for ENKTL patients.

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.

CD3-positive plasmablastic lymphoma reported in two cases: A potential diagnostic caveat

Plasmablastic lymphoma (PBL) is a rare aggressive subtype of mature large B cell lymphoma involving almost exclusively the extranodal regions particularly the oral cavity, frequently described in immunocompromised patients. PBL is characterized histologically by diffuse proliferation of large neoplastic cells resembling B immunoblasts or plasmablasts. The diagnosis of PBL can be difficult due to its ambiguous histopathological features mimicking most large cell lymphomas and lacking a distinctive immunophenotypic pattern. They typically lack expression of CD20 and CD79a but may express plasma cell marker, CD138. Aberrant immunoexpression of CD3, a T-cell marker in PBL in the absence of other B-cell markers is exceptionally rare, may potentially lead to incorrect interpretation. Herein, we report a case series of CD3-positive PBL of oral cavity in two individuals, which were initially misdiagnosed as high-grade T-cell lymphomas including extranodal NK/T-cell lymphoma, nasal type. Useful distinguishing clinical settings, histomorphological features, immunohistochemistry and molecular expression profiles of PBL are discussed.