Intrafollicular Epstein-Barr virus-positive large B cell lymphoma. A variant of “germinotropic” lymphoproliferative disorder

Epstein-Barr virus reactivation influences clonal evolution in human herpesvirus-8-related lymphoproliferative disorders

Background

Human herpesvirus‐8 (HHV8) is a lymphotropic virus associated with different lymphoproliferative disorders, including primary effusion lymphoma (PEL), multicentric Castleman’s disease (MCD), diffuse large B‐cell lymphomas, not otherwise specified, and the rare entity known as germinotropic lymphoproliferative disorder (GLPD). In PELs and GLPD the neoplastic cells also contain Epstein–Barr virus (EBV). In addition, occasional cases with atypical and overlapping features among these entities have been recognised, suggesting that the spectrum of the HHV8‐related lesions may not be fully characterised.

Aims

Here, we report two cases of lymphoproliferative disorder associated with HHV8 and EBV that further expand the spectrum of HHV8/EBV‐positive lymphoproliferative disease.

Methods and results

Case 1 represented HHV8/EBV‐positive extracavitary nodal PEL followed by pleural PEL. The striking characteristic of this case was the almost focal and intrasinusoidal localisation of the neoplastic cells and the association with Castleman’s disease features. In the second case, we found the entire spectrum of HHV8‐related disorders, i.e. MCD, GLPD, and PEL, coexisting in the same lymph node, underlining the variability, possible overlap and evolution among these entities. Both cases were well analysed with immunohistochemistry, determination of the EBV latency programme, and molecular analysis for clonality of immnoglobulin genes. In both patients, the disease followed an unexpected indolent course, both being still alive after 8 and 12 months, respectively.

Conclusion

Our findings represent further evidence of the overlap among HHV8/EBV‐positive lymphoproliferative disorders, and underline a grey zone that requires further study; they further confirm the experimental evidence that lytic EBV replication influences HHV8‐related tumorigenesis.

Germinotropic lymphoproliferative disorder: a systematic review

Germinotropic lymphoproliferative disorder is a rare and rather enigmatic novel entity with distinctive clinicopathological features, one of which is the typical co-infection by Human herpesvirus 8 and Epstein-Barr virus. Human herpesvirus 8 is a lymphotropic virus detected in Kaposi sarcoma, multicentric Castleman disease, primary effusion lymphoma, Human herpesvirus 8-positive diffuse large B cell lymphoma not otherwise specified, and germinotropic lymphoproliferative disorder. Co-infection by Human herpesvirus 8 and Epstein-Barr virus is identified only in two lymphoproliferative diseases: germinotropic lymphoproliferative disorder and primary effusion lymphoma, which are otherwise diseases with totally different clinical presentations and outcomes. Unlike primary effusion lymphoma mostly occurring in immunocompromised individuals and following an aggressive course, germinotropic lymphoproliferative disorder usually presents with single or multiple lymphadenopathy affecting mainly immunocompetent individuals and mostly follows an indolent course. Based on the PRISMA guidelines, we carried out a systematic search on PubMed/MEDLINE, Web of Science, Scopus, EMBASE, and Cochrane Library using the search terms "germinotropic" and "lymphoproliferative disorder." Current scientific literature reports just 19 cases of germinotropic lymphoproliferative disorder. The purpose of our systematic review is to improve our understanding of the disease, focusing on epidemiology, clinical presentation, pathological features, treatment, and outcome. In addition, we discuss the differential diagnosis with the other Human herpesvirus 8-related lymphoproliferative diseases as currently recognized in the World Health Organization classification, adding a focus on lymphoproliferative disorders showing overlapping features.

EBV-positive, HHV8-negative large B-cell lymphoma with an unusual germinotropic growth pattern in an immunocompetent patient

Clinicopathologic and cytogenetic findings of an unusual EBV+ve, HHV8-ve germinotropic lymphoma, with a nongerminal center immunophenotype occurring in an immunocompetent individual, are presented. A comprehensive literature search revealed a single report of three similar cases. These may represent a unique subset of EBV-positive large B-cell lymphomas in immunocompetent individuals.

Recent Advances in Aggressive Large B-cell Lymphomas: A Comprehensive Review

Diffuse large B-cell lymphoma (DLBCL) is an aggressive disease with considerable heterogeneity reflected in the 2008 World Health Organization classification. In recent years, genome-wide assessment of genetic and epigenetic alterations has shed light upon distinct molecular subsets linked to dysregulation of specific genes or pathways. Besides fostering our knowledge regarding the molecular complexity of DLBCL types, these studies have unraveled previously unappreciated genetic lesions, which may be exploited for prognostic and therapeutic purposes. Following the last World Health Organization classification, we have witnessed the emergence of new variants of specific DLBCL entities, such as CD30 DLBCL, human immunodeficiency virus-related and age-related variants of plasmablastic lymphoma, and EBV DLBCL arising in young patients. In this review, we will present an update on the clinical, pathologic, and molecular features of DLBCL incorporating recently gained information with respect to their pathobiology and prognosis. We will emphasize the distinctive features of newly described or emerging variants and highlight advances in our understanding of entities presenting a diagnostic challenge, such as T-cell/histiocyte-rich large B-cell lmphoma and unclassifiable large B-cell lymphomas. Furthermore, we will discuss recent advances in the genomic characterization of DLBCL, as they may relate to prognostication and tailored therapeutic intervention. The information presented in this review derives from English language publications appearing in PubMed throughout December 2015. For a complete outline of this paper, please visit: http://links.lww.com/PAP/A12.