NK-cell related neoplasms in Osaka, Japan

What Effect Does Epstein-Barr Virus Have on Extranodal Natural Killer/T-Cell Lymphoma Prognosis? A Review of 153 Reported Cases

The primary aim of this review is to identify the relationship between Epstein-Barr virus (EBV) and prognosis in extranodal natural killer/T-cell lymphoma (ENKTL). Additionally, a literature review of ENKTL was carried out. The investigators designed and implemented a 21-year literature review using the online databases PubMed and Google Scholar. The total number of cases analyzed was 153 (64 case reports; one comparative study; one systematic review). Information related to ENKTL from July 1999 to February 2021 was included in the study. Study variables included: patient demographics, tumor classification, screening modalities, tumor characteristics, symptomatology, treatment, and prognosis. The average age at diagnosis was 50.9 years (range: 4-90 years). Patients of Asian ethnicity were most commonly affected, and there was a 1.6:1 male to female ratio. ENKTL was most frequently detected in the head and neck region, and 53.1% of cases metastasized. Of all head and neck cases, the nose was the most affected location. Immunohistochemistry positivity included: EBV (32.0%), CD2 (96.6%), CD3ϵ (81.7%), CD43 (91.7%), CD56 (86.4%), Granzyme (97.1%), Perforin (90.9%), TIA-1 (97.8%), p53 (33.3%). The most frequently employed single treatment modality was chemotherapy alone, and 34.2% of patients expired within five years of diagnosis. The average follow-up period was 16.51 months (range: 0.25-66 months). EBV was significantly associated with metastatic ENKTL (χ² = 4.36; CV = 3.84; p = 0.037). We found no association between EBV and ENKTL prognosis (χ² = 17.2; CV = 21.0; p = 0.14).

Extranodal NK/T cell lymphoma, nasal type: An updated overview

Extranodal NK/T-cell lymphoma, nasal type (ENKTCL-NT) is an aggressive malignancy associated with Epstein-Barr virus infection, with a geographic and racial predilection for some Asian and Latin American countries. ENKTCL-NT manifests as a necrotic process affecting nasal or upper aerodigestive structures and, rarely, extranasal sites such as skin, and the gastrointestinal tract. ENKTCL-NT was characterized by its poor prognosis irrespective of clinical stage and therapy. However, during the last two decades, advances in its clinicopathologic, genetic and molecular characterization have been achieved, as have changes in the chemotherapy regimens that, in combination with radiotherapy, are significantly improving the survival of these patients, especially in initial stages. For these reasons, we present an overview of the historical background of ENKTCL-NT along with an updated review of its potential etiological factors, clinicopathologic and molecular features, as well as its prognostic models, current treatment protocols, and future directions on potential promising therapeutic approaches.

Extranodal NK/T-cell lymphoma, nasal type without evidence of EBV infection

Extranodal natural killer/T cell lymphoma-nasal type (EN-NK/T-NT) is extremely rare in Western countries; however, it is the most common subtype of peripheral T cell lymphoma in China. Despite this, there are a limited number of clinicopathological research studies on Epstein-Barr virus (EBV)-negative EN-NK/T-NTs. EBV-negative EN-NK/T-NT is a rare disease type, which has not been fully investigated. If other diagnostic criteria are met, such as the lesions being located predominantly in the upper aerodigestive tract, the presence of angiocentricity or angioinvasion, necrosis and expression of NK/T-cell phenotype, EN-NK/T-NT may be diagnosed, even if EBV is negative. In the present study, 99 cases of EN-NK/T-NTs were analyzed retrospectively, among which seven cases were EBV-negative EN-NK/T-NTs and selected for further investigation. In addition, the present study reviewed previously published research into EN-NK/T-NT, highlighting that EBV-negative EN-NK/T-NT is rare and that its geographical distribution is mainly in countries in Asia, Central America and South America. Patients with EBV-negative EN-NK/T-NT were all of Chinese ethnicity, with a median age of 32 years and primarily female. Furthermore, these patients shared similar clinicopathological characteristics (such as the tumor occurring mainly in the upper aerodigestive tract, the presence of vascular destruction, necrosis and cytotoxic phenotypes) to patients with EBV-positive EN-NK/T-NT. Immunohistochemistry and molecular analysis results indicated that tumor cells were primarily of NK or cytotoxic T origin; however, EBV-encoded small RNAs were not detected in any of these cases. Among the immunochemistry markers, T-bet was statistical significantly different between EBV-positive and -negative cases. Fluorescence in situ hybridization was also performed in two EBV-negative cases, including one case with a co-deletion of 6q21 and PR/SET domain 1 genes. There was only available follow-up data in 3/5 patients who survived for 37–113 months (median, 40 months). As EN-NK/T-NT can be diagnosed, even when EBV is negative, awareness of this subtype may prevent misdiagnosis or delayed diagnosis.

Extranodal NK/T-Cell Lymphoma, Nasal Type in Guatemala: An 86-Case Series Emphasizing Clinical Presentation and Microscopic Characteristics

Extranodal NK/T-cell lymphoma, nasal type (ENKTCL-NT) is a lymphoid malignancy that mainly affects the nasopharynx and is associated with the Epstein-Barr virus (EBV). Increased incidence is seen in some Latin American and Asian countries. In this study, we describe a case series of 86 Guatemalan patients with ENKTCL-NT from a single diagnostic head and neck center. We emphasize the distinctive clinical, microscopic, and immunohistochemical (IHC) features, as well as EBV positivity by in situ hybridization (ISH). Most of the patients (90.6%) were of Mayan descent and low socioeconomic status (SES). Males were more often affected than females, comprising 68.3% of cases. Patient age ranged from 8 to 71, with a mean of 34.7 years. All cases arose in the upper aerodigestive tract and mainly presented as a rapidly progressive, necrotizing midfacial process affecting the nasal, nasopharyngeal, sinonasal, palatal, and oropharyngeal structures. Microscopically, ENKTCL-NT showed a diffuse polymorphic and atypical lymphoid infiltrate. Angiocentric and angiodestructive growth patterns were present with associated necrosis. Peripheral hyaline necrosis of blood vessels was a histologic hallmark. The ISH and IHC profiles included positivity of EBV, LCA, CD3, CD45RO, CD30 (focal in 39.2%), granzyme-B, TIA-1, perforin (in 82.3%), and CD56 (in 83.7%). CD20 was negative, and the Ki-67 index ranged from 70 to 90%. In Guatemala, this lymphoma is strongly associated with people of low SES and indigenous ethnicity. When affected, the palatal mucosa provides the best site to obtain a representative biopsy. Since ENKTCL-NT is highly aggressive, it is extremely important to recognize the spectrum of clinical presentations and microscopic features in order to avoid misdiagnosis and treatment delay.

Guidelines for the management of mature T-cell and NK-cell neoplasms (excluding cutaneous T-cell lymphoma)

The peripheral T-cell neoplasms are a biologically and clinically heterogeneous group of rare disorders that result from clonal proliferation of mature post-thymic lymphocytes. Natural killer (NK) cell neoplasms are included in this group. The World Health Organization classification of haemopoietic malignancies has divided this group of disorders into those with predominantly leukaemic (disseminated), nodal, extra-nodal or cutaneous presentation. They usually affect adults and are more commonly reported in males than in females. The median age at diagnosis is 61 years with a range of 17-90 years. Although some subtypes may follow a relatively benign protracted course most have an aggressive clinical behaviour and poor prognosis. Excluding anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (ALCL), which has a good outcome, 5-year survival for other nodal and extranodal T-cell lymphomas is about 30%. Most patients present with unfavourable international prognostic index scores (>3) and poor performance status. The rarity of these diseases and the lack of randomized trials mean that there is no consensus about optimal therapy for T- and NK-cell neoplasms and recommendations in this guideline are therefore based on small case series, phase II trials and expert opinion.

Extranodal NK/T-cell lymphoma, nasal type

Extranodal NK/T-cell lymphoma, nasal type (ENKTCL), previously known as lethal midline granuloma is a distinct clinico-pathological entity associated with Epstein-Barr virus that typically causes destruction of the midface, palatal and orbital walls. In addition, ENKTCL can involve the skin, soft tissue, testes, gastrointestinal and upper respiratory tract. ENKTCL neoplastic cells express some T-cell associated antigens, most commonly CD2 and cytoplasmic CD3epsilon and, in favour of an NK-cell origin, CD56. Early stage disease may respond to radiotherapy alone, however late stage disease does not respond well to any available therapies. Overall, patients with ENKTCL have a cumulative probability of survival at 5 years ranging from 37.9% to 45.3%.