Fulminant EBV+ T-cell lymphoproliferative disorder following acute/chronic EBV infection: a distinct clinicopathologic syndrome

Unsuspected systemic Epstein-Barr virus-positive T-cell lymphoma of childhood diagnosed at autopsy in a potential homicide case

Systemic Epstein-Barr virus (EBV)-positive T-cell lymphoma of childhood (SETLC) is a rare, rapidly progressive, and often fatal disease of children and young adults characterized by monoclonal expansion of EBV-positive T cells in tissues or peripheral blood following infection with EBV. Its distinction from other EBV-positive T-cell lymphoproliferative disorders with overlapping features can be difficult, and particular diagnostic features may not be manifest until autopsy examination. We present the case of a 10-year-old boy with significant disability due to remote traumatic brain injury following non-accidental head trauma who died unexpectedly at home. Given the history of physical abuse and the potential for homicide charges, significant medicolegal implications arose with this case. Pathologic investigation ultimately revealed conclusive diagnostic features of SETLC including extensive proliferation of EBV-positive T cells in multiple organs. A natural manner of death was confirmed, thereby excluding delayed homicide related to complications of non-accidental head trauma.

Case Report: Primary Indolent Epstein-Barr Virus-Positive T-Cell Lymphoproliferative Disease Involving the Central Nervous System

Background

T-cell lymphoproliferative disease (T-LPD), characterized by primary Epstein–Barr virus (EBV) infection and clonal proliferation of T cells, occurs both in systemic and non-lymphatic organs. However, isolated indolent EBV-positive T-LPD involving the central nervous system has not been reported.

Case Presentation

A 48-year-old male who complained of headache, blurred vision, and weakness of the left lower limb for 1 month was hospitalized in our department. Neither neurological deficit nor palpable lymphadenopathy had been found. Bone marrow and laboratory tests had shown no abnormality as well. Enhanced MRI demonstrated enhanced cotton-like lesions up to 20 mm in diameter located in the right frontal, temporal, parietal and left parietal, occipital lobes with perifocal edema. Neuronavigation-assisted mini-craniotomy was performed to achieve total excision of the right temporal superficial lesion and identify the diagnosis. Pathological and EBV analysis described the lesion as indolent EBV-positive T-cell lymphoproliferative disease of the central nervous system (CNS). Then, a therapeutic regimen including whole-brain irradiation, chemotherapy, prednisolone, and aciclovir was given. Serial radiological imaging showed no signal of recurrence at 5 months' follow-up.

Conclusion

Primary indolent T-LPD in the central nervous system is quite rare, and it needs to be distinguished from aggressive cerebral T-cell lymphoma, metastatic tumors, and other CNS lesions.

Epstein-Barr virus-associated T- and NK-cell lymphoproliferative diseases: an update and diagnostic approach

Epstein-Barr virus (EBV)-positive T-cell and natural killer (NK)-cell lymphoproliferative diseases (EBV-TNKLPD) are a group of uncommon disorders characterised by EBV infection of T- and NK-cells. As a group, EBV-TNKLPD are more commonly encountered in Asians and Native Americans from Central and South America compared to Western populations. They encompass a spectrum of entities that range from non-neoplastic lesions such as EBV-associated haemophagocytic lymphohistiocytosis (EBV-HLH) to more chronic conditions with variable outcomes such as chronic active EBV infections (CAEBV) of T- and NK-cell type (cutaneous and systemic forms) and malignant diseases such as systemic EBV-positive T-cell lymphoma of childhood, aggressive NK-cell leukaemia, extranodal NK/T-cell lymphoma, nasal-type, and primary EBV-positive nodal T/NK-cell lymphoma. Due to their rarity, broad clinicopathological spectrum and significant morphological and immunophenotypic overlap, the diagnosis and precise classification of EBV-TNKLPD often pose a challenge to clinicians and pathologists. Correct classification of this group of rare diseases relies heavily on the age of onset, disease presentation, duration of symptoms and cell of origin (T- vs NK-cell lineage). In this review, we provide an update on the clinicopathological and molecular features of the various EBV-TNKLPD entities occurring in non-immunocompromised patients and present a practical algorithmic approach for the general pathologist who is confronted with these disorders in routine clinical practice.

Unusual lymphoid malignancy and treatment response in two children with Down syndrome

BACKGROUND

Lymphoid malignancies other than acute lymphoblastic leukemia (ALL) are rare in children with Down syndrome (DS). Information about the toxicity of chemotherapy and prognosis is largely derived from the experience of children with DS and ALL or children without DS.

PROCEDURE

We describe the treatment and outcome of two unusual lymphoid malignancies in children with DS. One patient was diagnosed with Burkitt lymphoma (BL) and the second, after treatment for B precursor ALL, with T-cell EBV-positive proliferative disorder (LPD).

RESULTS

BL was treated with standard doses of LMB group B therapy subsequently intensified to group C therapy, including high-dose methotrexate (HD-MTX, 3-8 g/m² ). The patient did not experience excessive toxicity and remains in complete remission 13 months later. Despite presentation with disseminated disease the patient with T-cell EBV-positive LPD after treatment for B precursor ALL responded to dexamethasone and rituximab and remains in complete remission two years later.

CONCLUSIONS

Upfront reduction of the high treatment intensity, which is associated with excellent survival outcomes in BL, may not be warranted in all children with DS. Response to therapy and prognosis of T-cell EBV-positive LPD in a patient with DS was not predicted by reported experience in the absence of DS.

The Global Landscape of EBV-Associated Tumors

Epstein-Barr virus (EBV), a gamma-1 herpesvirus, is carried as a life-long asymptomatic infection by the great majority of individuals in all human populations. Yet this seemingly innocent virus is aetiologically linked to two pre-malignant lymphoproliferative diseases (LPDs) and up to nine distinct human tumors; collectively these have a huge global impact, being responsible for some 200,000 new cases of cancer arising worldwide each year. EBV replicates in oral epithelium but persists as a latent infection within the B cell system and several of its diseases are indeed of B cell origin; these include B-LPD of the immunocompromised, Hodgkin Lymphoma (HL), Burkitt Lymphoma (BL), Diffuse Large B cell Lymphoma (DLBCL) and two rarer tumors associated with profound immune impairment, plasmablastic lymphoma (PBL) and primary effusion lymphoma (PEL). Surprisingly, the virus is also linked to tumors arising in other cellular niches which, rather than being essential reservoirs of virus persistence in vivo, appear to represent rare cul-de-sacs of latent infection. These non-B cell tumors include LPDs and malignant lymphomas of T or NK cells, nasopharyngeal carcinoma (NPC) and gastric carcinoma of epithelial origin, and leiomyosarcoma, a rare smooth muscle cell tumor of the immunocompromised. Here we describe the main characteristics of these tumors, their distinct epidemiologies, histological features and degrees of EBV association, then consider how their different patterns of EBV latency may reflect the alternative latency programmes through which the virus first colonizes and then persists in immunocompetent host. For each tumor, we discuss current understanding of EBV's role in the oncogenic process, the identity (where known) of host genetic and environmental factors predisposing tumor development, and the recent evidence from cancer genomics identifying somatic changes that either complement or in some cases replace the contribution of the virus. Thereafter we look for possible connections between the pathogenesis of these apparently different malignancies and point to new research areas where insights may be gained.

A clinicopathologic study of the spectrum of systemic forms of EBV-associated T-cell lymphoproliferative disorders of childhood: A single tertiary care pediatric institution experience in North America

BACKGROUND

Systemic forms of EBV-associated T-cell lymphoproliferative disorders of childhood (S-EBV-T-LPD) comprise three major forms: EBV-positive hemophagocytic lymphohistiocytosis (EBV-HLH), systemic EBV-positive T-cell lymphoma (S-EBV-TCL), and systemic chronic active EBV infection (S-CAEBV). These disorders occur rarely in children in Western countries. Here, we described eight children of such entities.

DESIGN

Eight cases (six clinical and two autopsy) with S-EBV-T-LPD of childhood were retrospectively identified from 1990 to 2015. Clinicopathologic parameters including histomorphology, immunophenotype, EBV studies, and T-cell receptor gene rearrangement studies were recorded.

RESULTS

Patients include five females and three males of Hispanic, Asian, and Caucasian origins with an age range of 14 months to 9 years. Fever, hepatosplenomegaly, cytopenias, abnormal EBV serologies, and very high EBV viral loads were common findings. Histologic findings showed EBV⁺ T-cell infiltrates with variable degrees of architectural distortion and cytologic atypia ranging from no to mild cytologic atypia to overt lymphoma and tissue hemophagocytosis. All showed aberrant CD4⁺ or CD8⁺ T cells with dim to absent CD5, CD7, and CD3, and bright CD2 and CD45 by flow cytometry or loss of CD5 by immunohistochemistry. TCR gene rearrangement studies showed monoclonal rearrangements in all clinical cases (6/6). Outcomes were poor with treatment consisting of chemotherapy per the HLH-94 or HLH-2004 protocols with or without bone marrow transplant.

CONCLUSION

In this large pediatric clinicopathologic study of S-EBV-T-LPD of childhood in the United States, EBV-HLH, S-EBV-TCL, and S-CAEBV show many overlapping features. Diagnosis is challenging, and overall outcome is poor using current HLH-directed therapies.

EBV-Associated Lymphoproliferative Disorders: Update in Classification

Although about 90% of the world's population is infected by EBV only a small subset of the related infections result in neoplastic transformation. EBV is a versatile oncogenic agent involved in a multitude of hematopoietic, epithelial, and mesenchymal neoplasms, but the precise role of EBV in the pathogenesis of many of the associated lymphoid/histiocytic proliferations remains hypothetical or not completely understood. Additional studies and use of evolving technologies such as high-throughput next-generation sequencing may help address this knowledge gap and may lead to enhanced diagnostic assessment and the development of potential therapeutic interventions.

Epstein-Barr Virus-Associated T and NK-Cell Lymphoproliferative Diseases

EBV-associated T and NK-cell lymphoproliferative diseases (EBV-T/NK LPDs) are characterized by the transformation and proliferation of EBV-infected T or NK cells. The 2016 revised World Health Organization classification recognizes the following EBV-positive lymphoproliferative disorders (LPD): chronic active EBV infection (CAEBV) of T- and NK-cell type (cutaneous and systemic forms), systemic EBV-positive T-cell lymphoma of childhood, aggressive NK-cell leukemia, extranodal NK/T-cell lymphoma, nasal type, and the new provisional entity primary EBV-positive nodal T/NK-cell lymphoma. EBV-associated hemophagocytic lymphohistiocytosis (HLH), although not included in the WHO classification because it is a reactive, inflammatory disease, is included in this review because it can be life-threatening and may have overlapping features with other EBV+ T/NK LPDs. EBV+ T/NK LPDs are rare diseases difficult to diagnose and manage properly, because some LPDs have unusual presentations, and discrepancies between clinical and histological findings might be encountered. Furthermore, EBV+ T/NK disorders share some clinico-pathological features, and may evolve into other categories during the clinical course, including malignant transformation of CAEBV. Here, we review the EBV+ T/NK LPDs in terms of their definitions, clinical features, histology, immunophenotype, molecular findings, and pathogenesis. This review aims to increase our understanding and awareness of the differential diagnosis among the different EBV+ T/NK LPDs. New insights into the genetic characteristics of these disorders will also be discussed.

Epstein-Barr virus (EBV)-associated lymphoid proliferations, a 2018 update

Epstein-Barr virus (EBV) has been linked to many human neoplasms including hematopoietic, epithelial, and mesenchymal tumors. Since our original review of EBV-associated lymphoproliferative disorders in 2007, many advances and developments have been reported. In this review, we will examine the recent advances in EBV-associated lymphoid/histiocytic proliferations, dividing them into reactive, B cell, T/NK cell, immunodeficiency-related, and histiocytic/dendritic cell proliferations.

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.

Imaging findings in immunosuppressed patients with Epstein Barr virus-related B cell malignant lymphoma

OBJECTIVE

The purpose of this study was to describe multimodality imaging findings in immunosuppressed patients with Epstein-Barr virus (EBV)-related malignant lymphoproliferative diseases.

CONCLUSION

EBV-related malignant lymphoproliferative diseases share common features with other aggressive lymphomas, including a high degree of extranodal involvement, tumor vascularization, and tumor necrosis. Cognizance of the particular underlying diseases and conditions associated with the development of EBV-related lymphoproliferative diseases and associated imaging results should provide more accurate diagnosis.

The 2008 WHO classification of lymphomas: implications for clinical practice and translational research

The 4(th) edition of the WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues published in 2008 builds upon the success of the 2001 3(rd) edition; new entities are defined, and solutions for problematic categories are sought. Recent studies have drawn attention to the biological overlap between classical Hodgkin lymphoma (CHL) and diffuse large B-cell lymphomas (DLBCL). Similarly, there is a greater appreciation of the borderlands between Burkitt lymphoma and DLBCL. Strategies for the management of these borderline lesions are proposed. Additionally, age-specific and site-specific factors play an important role in the definition of several new entities, which also have biological underpinnings. Among the peripheral T-cell lymphomas (PTCL), more precise definitions were introduced for several entities, including anaplastic large cell lymphoma, angioimmunoblastic T-cell lymphoma, enteropathy-associated T-cell lymphoma, and subcutaneous panniculitis-like T-cell lymphoma. Several new variants of primary cutaneous T-cell lymphomas are proposed. Finally, the subclassification and categorization of the most common lymphoma subtypes, follicular lymphoma (FL) and DLBCL, were altered to enhance diagnostic accuracy and aid in clinical management. The 2008 WHO classification also draws attention to early events in lymphomagenesis. These lesions help delineate the earliest steps in neoplastic transformation and generally mandate a conservative therapeutic approach. The 2001 classification was rapidly adopted for clinical trials and successfully served as a common language for scientists comparing genetic and functional data. The modifications made in the 2008 classification are the result of this successful partnership among pathologists, clinicians, and biologists, but are only a stepping stone to the future.

NK-cell lymphomas and leukemias: a spectrum of tumors with variable manifestations and immunophenotype

Natural killer (NK) cells are lymphocytes that have some phenotypic and functional similarities to cytotoxic T cells but do not express the T-cell receptor complex. NK-cell malignancies may be localized or disseminated at initial examination, and most behave aggressively. The variable presentation of NK-cell lymphomas and leukemias suggests that they represent a spectrum of disease, with Epstein-Barr virus (EBV) implicated in the pathogenesis of most cases. Using cases presented in Session 10 of the 2005 Society for Hematopathology/European Association for Haematopathology Workshop on T-cell and NK-cell malignancies, we discuss outstanding issues in the classification and diagnosis of NK-cell malignancies. These difficulties are related to unusual sites of manifestation, atypical immunophenotypic features, and EBV+ T-cell tumors that resemble classical extranodal NK/T-cell lymphoma, nasal-type (EN-NK/T-NT). Although some of these cases can be grouped into ENNK/T-NT, classification of tumors that have atypical or discordant features will remain controversial, particularly when EBV is absent.

T-cell and NK-cell posttransplantation lymphoproliferative disorders

Posttransplantation lymphoproliferative disorders (PTLDs) of T-cell or natural killer (NK)-cell origin are an uncommon heterogeneous group of lymphoid proliferations that fulfill the criteria for one of the T- or NK-cell lymphomas/leukemias. This report summarizes 130 T/NK-cell PTLDs reported in the literature or presented at the Society for Hematopathology/European Association for Haematopathology Workshop on T/NK-cell malignancies. The T/NK-cell PTLDs occur at a median of 66 months following transplantation and are usually extranodal. The most common types reported are peripheral T-cell lymphoma, unspecified, and hepatosplenic T-cell lymphoma. Approximately one third are Epstein-Barr virus (EBV)+. The median survival is 6 months. EBV+ cases have a significantly longer survival than EBV- cases, even when indolent T-cell large granular lymphocytic leukemias are included among the EBV- cases. Many T/NK-cell PTLDs have been treated with chemotherapy, often together with decreased immunosuppression, but there are infrequent patients who have done well without chemotherapy or radiation.

Epstein-Barr virus-associated peripheral T-cell and NK-cell proliferative disease/lymphoma: clinicopathologic, serologic, and molecular analysis

Peripheral T-cell proliferative disease/lymphoma is a group of diseases which exhibits heterogeneity in clinical manifestations, pathological findings and outcomes. They are highly associated with the Epstein-Barr virus (EBV) infection. It is likely that EBV plays an important role in the tumorigenesis. From January 1997 through April 2000, we identified 100 patients. One hundred healthy age- and sex- matched controls were selected. Serologic tests for the EBV infection and the study of EBV genomes in circulating non-T cells (CD3- cells), T cells (CD3+ cells), and T-cell subsets (CD4+ and CD8+ cells) were performed. The main features were prolonged fever, weight loss, hepatosplenomegaly, lymphadenopathy, multiorgan involvement, anemia, and high serum alkaline phosphatase and lactate dehydrogenase. Fifty-one patients had an aggressive course and died; median survival was 21 months. Chemotherapy was not effective in improving survival. Anti-viral capsid antigen-IgG and anti-early antigen-IgG were significantly elevated, whereas there was no significant difference in anti-EBV nuclear antigen. EBV internal repeat-1 region (IR-1) in the peripheral blood CD3+ cells was detected in 65% of the patients but in none of the controls. For the CD3- cells, EBV IR-1 was detected in 88% of the patients and 50% of the controls. Among twenty-five patients whose CD3+ cells were positive for EBV IR-1, 6 (24%) showed EBV IR-1 in only CD4+ cells, 6 (24%) in only CD8+ cells, and 13 (52%) in both CD4+ and CD8+ cells. The 30-bp deletion variant of the EBV latent membrane protein-1 gene was significantly higher in the patients than in the controls. These data support the chronic infective process. The EBV which is dormant in non-T cells may infect T cells and contribute to the pathogenesis of disease in a select group of patients.