Classic and extracavitary primary effusion lymphoma in 51 HIV-infected patients from a single institution

Primary effusion lymphoma: therapeutic strategies targeting viral and cellular mechanisms

INTRODUCTION

Primary effusion lymphoma (PEL) is a rare subtype of B-cell lymphoma primarily affecting immunocompromised and elderly individuals. Given the dismal survival rates associated with traditional treatments, studying novel therapeutic approaches to improve patient outcomes is critical.

AREAS COVERED

This review focuses on developing therapeutic options for PEL that target particular viral and cellular mechanisms involved in PEL pathogenesis. Since the CHOP regimen was associated with a lower median survival rate, alternative treatments, including stem cell transplantation, have also been explored, but have generally produced unsatisfactory results. Therefore, novel therapeutic agents are under investigation, including antiretroviral drugs targeting viral pathways and treatments targeting particular cellular processes, such as DNA damage, epigenetics, apoptotic, and immune-modulatory pathways showing promising outcomes in preclinical and clinical research, increasing PEL treatment efficacy while minimizing toxicity. In this review, we conducted a comprehensive literature search using PubMed, and Google Scholar for studies published between 1989 and 2024.

EXPERT OPINION

Further research is needed to refine the appropriate combination methods and strategies behind drug interactions. Targeted therapies could be investigated further to improve therapeutic efficacy and reduce toxicity in this type of lymphoma.

Primary Effusion Lymphoma Prognostic Score (PEL-PS): A Validated International Prognostic Score in HIV-Associated Primary Effusion Lymphoma

Primary effusion lymphoma (PEL) is an HIV-associated B-cell non-Hodgkin lymphoma (NHL) caused by Kaposi sarcoma herpesvirus (KSHV). There is no validated prognostic model in PEL, and prognosis is thought to be poor compared to other HIV-associated NHL. We derived the PEL-Prognostic score (PEL-PS) from an international real-world training set of 59 patients with HIV-associated PEL who received first-line anthracycline-containing chemotherapy from the HIV and AIDS Malignancy Branch at the National Cancer Institute (NCI) in the United States and the National Center for HIV Malignancy at the Chelsea and Westminster Hospital (CWH) in England from 2000 to 2022. We identified prognostic factors associated with overall survival (OS). In a multivariable Cox model, ECOG ≥ 3 (p = 0.007; hazard ratio [HR] = 4.0 [95% CI: 1.5-11.1]) and hemoglobin < 8 g/dL (p = 0.006; HR = 3.8 [95% CI: 1.5-9.7]) were jointly associated with lower survival probability. The resulting PEL-PS separated patients with no negative prognostic factors (score 0: hemoglobin ≥ 8 g/dL and ECOG ≤ 2, 48.1% of patients) with median OS of 10.6 years versus patients with 1-2 negative prognostic factors (score 1-2: hemoglobin < 8 g/dL and/or ECOG ≥ 3, 51.9% of patients) with median OS of 0.8 years (p < 0.0001). The PEL-PS was then validated in 58 patients with HIV-associated PEL treated with first-line anthracycline-containing chemotherapy at Hôpital Saint-Louis in France over the same period: median OS in patients with PEL-PS 0 was 16.9 years versus 0.6 years in patients with PEL-PS score of 1-2 (p < 0.0001). The PEL-PS identifies patients with good and poor prognosis. Patients with poor prognosis may benefit from novel therapies.

An Unusual Case of Extracavitary/Solid Variant Primary Effusion Lymphoma With Associated Hemophagocytic Lymphohistiocytosis

Primary effusion lymphoma (PEL) is a rare, aggressive large B-cell lymphoma variant that is invariably associated with human herpesvirus 8 (HHV8), predominantly in human immunodeficiency virus (HIV)-infected patients, and its oncogenicity is often augmented by coinfection with Epstein-Barr virus. It typically presents as a serous effusion in body cavities without detectable solid tumors. The extracavitary variant of PEL may represent a diagnostic challenge. A 37-year-old man with HIV/acquired immunodeficiency syndrome (AIDS) was transferred to our hospital for evaluation of a mediastinal mass with associated clinically diagnosed hemophagocytic lymphohistiocytosis (HLH), fever, pancytopenia, hepatosplenomegaly, retroperitoneal lymphadenopathy, and wasting syndrome. Contrast-enhanced computed tomography showed a large soft tissue mass extending along the middle/posterior mediastinum into the left hilum and a large left pleural effusion. Endoscopic fine-needle biopsy of the lesion showed sheets of large pleomorphic lymphoma cells with prominent nucleoli and abundant cytoplasm. These cells were also seen on the cytospin smear of pleural fluid. Immunohistochemical stains showed lymphoma cells positive for CD3 (small subset), CD45, CD138, MUM-1, and HHV8 and negative for CD5, CD20, CD30, ALK1, AE1/3, and PAX-5. The lymphoma cells were also positive for Epstein-Barr virus-encoded RNA (EBER) (in situ hybridization). Solid masses in extracavitary PEL have been shown to involve lymph nodes and/or solid organs such as the gastrointestinal tract, lung, liver, spleen, and skin, with a similar phenotype as classic PEL except that they may express B-cell markers with lower expression of CD45 and/or aberrant coexpression of T-cell antigens. This case illustrates the unusual manifestation of PEL as a mediastinal mass with associated HLH.

Unraveling the Kaposi Sarcoma-Associated Herpesvirus (KSHV) Lifecycle: An Overview of Latency, Lytic Replication, and KSHV-Associated Diseases

Kaposi sarcoma-associated herpesvirus (KSHV) is an oncogenic gammaherpesvirus and the etiological agent of several diseases. These include the malignancies Kaposi sarcoma (KS), primary effusion lymphoma (PEL), and multicentric Castleman disease (MCD), as well as the inflammatory disorder KSHV inflammatory cytokine syndrome (KICS). The KSHV lifecycle is characterized by two phases: a default latent phase and a lytic replication cycle. During latency, the virus persists as an episome within host cells, expressing a limited subset of viral genes to evade immune surveillance while promoting cellular transformation. The lytic phase, triggered by various stimuli, results in the expression of the full viral genome, production of infectious virions, and modulation of the tumor microenvironment. Both phases of the KSHV lifecycle play crucial roles in driving viral pathogenesis, influencing oncogenesis and immune evasion. This review dives into the intricate world of the KSHV lifecycle, focusing on the molecular mechanisms that drive its latent and lytic phases, their roles in disease progression, and current therapeutic strategies.

Rare Cutaneous Primary Presentation of Extracavitary Primary Effusion Lymphoma

ABSTRACT

Primary effusion lymphoma (PEL) is a rare and aggressive B-cell lymphoma typically associated with human herpesvirus 8 (HHV-8) and Epstein-Barr virus infections. It classically presents as a malignant effusion in body cavities, but rarely presents with an extracavitary variant characterized by solid tumors in lymph nodes or extranodal sites such as the gastrointestinal tract, skin, lungs, and nervous system. This case report describes an unusual presentation of primary cutaneous extracavitary PEL in an HIV-positive patient that has only been reported in 8 cases previously. The patient presented with a skin nodule in the right supraclavicular area. Histopathologic examination showed a malignant infiltrate in the dermis composed of sheets of plasmablasts. The immunophenotype of the cells shows the characteristic coinfection with HHV-8 and Epstein-Barr virus. The case presented herein contributes to expand the reported literature on primary cutaneous extracavitary PEL and performs a comprehensive review of this entity, which most dermatopathologists are unfamiliar with.

Extra-Cavitary Primary Effusion Lymphoma in a Patient Co-infected With HIV-1 and HIV-2: A Case Review

Extra-cavitary primary effusion lymphoma (PEL), often associated with human herpes virus 8 (HHV8) infection, represents a rare and aggressive form of non-Hodgkin lymphoma, which is predominantly found in individuals with severe immunosuppression. As an acquired immunodeficiency syndrome (AIDS)-associated lymphoma, PEL typically manifests in the context of advanced human immunodeficiency virus (HIV) infection, requiring tailored therapeutic approaches to manage both the lymphoma and underlying immunodeficiency. A 53-year-old male patient from Cape Verde presented with a three-day history of fever, night sweats, right iliac fossa pain, hematochezia, and an unintentional weight loss of five kilograms over the previous two months. A laboratory study revealed a previously undiagnosed co-infection with HIV-1 and HIV-2, with a CD4+ T-cell count of 63/μL. The abdominal-pelvic computed tomography (CT) scan revealed hepatosplenomegaly with hypodense nodular lesions and prominent lymph nodes in the celiac-mesenteric, axillary, and cervical regions. Lung imaging showed non-specific nodules. An extensive investigation for opportunistic infections was conducted, with a bronchoalveolar lavage culture test positive for Mycobacterium xenopi and a colon biopsy indicating Cytomegalovirus colitis. Further histological examination from a gastric biopsy revealed the diagnosis of the solid variant of PEL. The patient initiated treatment for opportunistic infections followed by antiretroviral therapy. However, he experienced multiple complications and due to his deteriorating condition, chemotherapy was not initiated and he ultimately died. This rare clinical case of lymphoma in a patient co-infected with HIV-1 and HIV-2, the first of its kind to be reported, to the authors' knowledge, underscores the diagnostic and therapeutic challenges associated with this condition.

The role of autologous bone marrow transplantation in primary effusion lymphoma: a case report and literature review

Primary effusion lymphoma (PEL) is an aggressive and rare type of diffuse large B-cell lymphoma (DLBL) that commonly presents itself as pleural, pericardial or peritoneal effusion without lymph node or extranodal involvement in immunosuppressed patients, such as HIV-positive or transplanted receptors. On rare occasions, it may be found in solid sites without effusion, in an immunophenotypically and morphologically similar neoplasm well-known as extracavitary PEL (EC-PEL). Both PEL and EC-PEL are associated with extremely poor prognosis. Due to the rarity of these entities, ther e are no gold standard treatments . Here we discuss the role of autologous bone marrow transplant (auto-BMT) in the treatment of these patients as well as report the case of a young HIV-positive male diagnosed with both PEL and EC-PEL, who underwent a salvage therapy with auto-BMT and achieved complete and sustained remission eight years after the diagnosis.

HHV-8-associated diseases in transplantation: A case report and narrative review focused on diagnosis and prevention

BACKGROUND

Human herpes virus 8 (HHV-8) or Kaposi sarcoma herpesvirus (KSHV) is an opportunistic oncovirus that causes multiple pathologic entities.

METHODS

We present a case of fatal HHV-8-associated multisystem illness with disseminated Kaposi sarcoma and HHV8-associated lymphoproliferative disorder with systemic inflammation. We conducted a narrative review of the literature on HHV-8 in transplantation with a goal of illuminating the spectrum of HHV-8-associated diseases in this vulnerable population, modes of disease transmission, and the potential role for donor and recipient screening.

RESULTS

HHV-8-associated KS, primary effusion lymphoma (PEL), multicentric Castleman disease (MCD), and KSHV inflammatory cytokine disorder (KICS) may affect transplant recipients; with the exception of KS, these conditions are rare but carry high morbidity and mortality.

CONCLUSION

HHV-8-associated diseases have diverse and protean manifestations in transplant recipients, with potentially fatal outcomes. HHV-8 seroprevalence among organ donors and the magnitude of risk for donor-derived HHV-8 infection or clinically significant disease remain unknown and require further study.

The Mitochondrial Ubiquitin Ligase MARCHF5 Cooperates with MCL1 to Inhibit Apoptosis in KSHV-Transformed Primary Effusion Lymphoma Cell Lines

Kaposi's sarcoma-associated herpesvirus (KSHV) causes several malignancies in people with HIV including Kaposi's sarcoma and primary effusion lymphoma (PEL). We have previously shown that PEL cell lines require myeloid cell leukemia-1 (MCL1) to inhibit apoptosis. MCL1 is an oncogene that is amplified in cancers and causes resistance to chemotherapy regimens. MCL1 is thus an attractive target for drug development. The emerging clinical relevance and therapeutic potential of MCL1 motivated us to study the roles of this oncogene in PEL in depth. Using a systems biology approach, we uncovered an unexpected genetic interaction between MCL1 and MARCHF5 indicating that they function in the same pathway. MARCHF5 is an E3 ubiquitin ligase most known for regulating mitochondrial homeostasis and antiviral signaling, but not apoptosis. We thus investigated how MCL1 and MARCHF5 cooperate to promote PEL cell survival. CRISPR knockout (KO) of MARCHF5 in PEL cell lines resulted in a significant increase in apoptosis despite the presence of MCL1. The anti-apoptotic function of MARCHF5 was dependent on its E3 ligase and dimerization activities. Loss of MARCHF5 or inhibition of the 26S proteasome furthermore stabilized the MCL1 antagonist NOXA without affecting levels of MCL1. Interestingly, NOXA KO provides a fitness advantage to PEL cells suggesting that NOXA is the pro-apoptotic signal that necessitates the anti-apoptotic activities of MCL1 and MARCHF5. Finally, endogenous reciprocal co-immunoprecipitation experiments show that MARCHF5 and NOXA are found in the same protein complex. Our findings thus provide the mechanistic link that underlies the genetic interaction between MCL1 and MARCHF5. We propose that MARCHF5 induces the degradation of the MCL1 antagonist NOXA thus reinforcing the pro-survival role of MCL1 in these tumor cells. This newly appreciated interaction of the MCL1 and MARCHF5 oncogenes may be useful to improve the design of combination therapies for KSHV malignancies.

Human immunodeficiency virus-associated Lymphomas: EHA-ESMO Clinical Practice Guideline for diagnosis, treatment and follow-up

This EHA-ESMO Clinical Practice Guideline provides key recommendations for managing HIV-associated lymphomas.The guideline covers clinical, imaging and pathological diagnosis; staging and risk assessment; treatment and follow-up.The author group encompasses a multidisciplinary group of experts from different institutions and countries in Europe.Recommendations are based on available scientific data and the authors' collective expert opinion.

Combined Flow-Fluorescence in situ hybridization to HHV-8 and EBV reveals the viral heterogeneity of primary effusion lymphoma

Primary effusion lymphoma (PEL) is a rare B-cell non-Hodgkin lymphoma associated with Kaposi Sarcoma-associated herpesvirus (KSHV/HHV8) infection. Lymphoma cells are coinfected with Epstein-Barr virus (EBV) in 60-80% of cases. Tools allowing a reliable PEL diagnosis are lacking. This study reports PEL diagnosis in 4 patients using a Flow-Fluorescence in situ hybridization (FlowFISH) technique that allowed detection of differentially expressed EBV and HHV8 transcripts within the same sample, revealing viral heterogeneity of the disease. Moreover, infected cells exhibited variable expressions of CD19, CD38, CD40, and CD138. Therefore, FlowFISH is a promising tool to diagnose and characterize complex viral lymphoproliferations.

Promising immunotherapeutic approaches for primary effusion lymphoma

Primary effusion lymphoma (PEL) is a large B-cell neoplasm usually presenting as a serious effusion in body cavities without detectable tumor masses. It is an AIDS-related non-Hodgkin's lymphoma (HL) with human herpes virus 8 (HHV8)/Kaposi sarcoma-associated herpes virus (KSHV) infection. A combination antiretroviral therapy (cART) prolongs the lifespan of AIDS and AIDS-related malignant lymphoma patients, but PEL continues to have a dismal prognosis. PEL showed disappointing outcomes with standard chemotherapy such as CHOP or CHOP-like regimens. A PEL status highlights the urgent need for new therapeutic approaches and treatment strategies and improve clinical outcomes. This review discusses the current knowledge and some recent clinical trials for PEL in the platform of immunotherapy as well as promising future immunotherapeutic approaches for PEL.

Extracavitary primary effusion lymphoma presenting as a solitary brain mass

Primary effusion lymphoma (PEL) is an uncommon B-cell lymphoma associated with human herpesvirus 8 and comprises 3-4% of all HIV-related lymphomas. It traditionally presents as a pleural, pericardial, and/or peritoneal effusion, though it can occasionally manifest as an extracavitary or solid mass in the absence of an effusion. The extracavitary or solid variant of primary effusion lymphoma has been reported in the skin, gastrointestinal tract, lung, and lymph nodes. However, very few cases have been reported in the central nervous system. We describe a case of extracavitary or solid variant of primary effusion lymphoma presenting as a brain mass in an HIV-positive man, highlighting the clinicopathologic and immunophenotypic findings of a rare entity.

Outcomes in Kaposi's sarcoma-associated herpesvirus -associated primary effusion lymphoma and multicentric Castleman's disease in patients with human immunodeficiency virus (HIV) in a safety-net hospital system

OBJECTIVE

To describe cases of Kaposi's sarcoma-associated herpesvirus (KSHV)-associated multicentric Castleman's disease (MCD) and primary effusion lymphoma (PEL) in patients with HIV from a large, safety-net hospital system in Dallas, Texas, USA.

METHODS

We conducted a retrospective review of patients with HIV-associated PEL and/or MCD.

RESULTS

Twelve patients with PEL and 10 patients with MCD were identified. All patients were male and 17 of 20 were men who have sex with men; 66.7% of PEL patients and 50% of MCD patients had concurrent KS at the time of diagnosis; 42% of patients with PEL and 20% of patients with MCD died during the follow-up period. We noted improved survival in our cohort compared to previous studies, particularly in our PEL patients with a median survival of 11.4 months compared to 3-6-month median survival historically. Median follow-up time for MCD patients was 17.5 months. This improved survival is despite suboptimal antiretroviral therapy (ART) adherence at diagnosis, with only 50% of patients on ART at the time of MCD/PEL diagnosis.

CONCLUSION

These data highlight the importance of early recognition of PEL and MCD, and the larger-scale efforts needed to better understand the pathogenetic drivers of clinical outcomes in patients affected by KSHV-related diseases.

Inhibition of NEK2 Promotes Chemosensitivity and Reduces KSHV-positive Primary Effusion Lymphoma Burden

Non-Hodgkin lymphoma (NHL) is a common cancer in both men and women and represents a significant cancer burden worldwide. Primary effusion lymphoma (PEL) is a subtype of NHL infected with Kaposi sarcoma-associated herpesvirus (KSHV). PEL is an aggressive and lethal cancer with no current standard of care, owing largely to its propensity to develop resistance to current chemotherapeutic regimens. Here, we report a reliance of KSHV-positive PEL on the mitotic kinase, NEK2, for survival. Inhibition of NEK2 with the inhibitor, JH295, resulted in caspase 3-mediated apoptotic cell death of PEL. Furthermore, NEK2 inhibition significantly prolonged survival and reduced tumor burden in a PEL mouse model. We also demonstrate that the ABC transporter proteins, MDR1 and MRP, are most active in PEL and that inhibition of NEK2 in PEL reduced the expression and activity of these ABC transporter proteins, which are known to mediate drug resistance in cancer. Finally, we report that JH295 treatment sensitized lymphomas to other chemotherapeutic agents such as rapamycin, resulting in enhanced cancer cell death. Overall, these data offer important insight into the mechanisms underlying PEL survival and drug resistance, and suggest that NEK2 is a viable therapeutic target for PEL.

SIGNIFICANCE

The mitotic kinase, NEK2, is important for the survival of KSHV-positive PEL. NEK2 inhibition resulted in PEL apoptosis and reduced tumor burden in a mouse model. NEK2 inhibition also reduced drug resistance.

Complete response to front-line therapies is associated with long-term survival in HIV-related lymphomas in Taiwan

BACKGROUND

The prognosis for people living with HIV (PLWH) who develop lymphomas has been greatly improved by combination antiretroviral therapy (cART) and anti-CD20 monoclonal antibodies. However, real-world clinical data on this patient group in Asia are limited.

METHODS

Treatment outcomes were retrospectively examined for 104 PLWH with lymphomas between 2000 and 2019. The cohort comprised five PLWH with Hodgkin lymphoma (HL) and 99 with non-Hodgkin lymphomas, including 61 with diffuse large B-cell lymphoma (DLBCL), 19 with Burkitt lymphoma (BL), nine with primary central nervous system lymphoma (PCNSL) and ten with other subtypes.

RESULTS

The 5-year overall survival (OS) rates were as follows: HL (100%), PCNSL (76.2%), other subtypes (60.0%), BL (57.4%), and DLBCL (55.6%). Individuals who achieved complete response (CR) to front-line therapies had a significantly better 5-year OS rate than those without (96.2% vs. 17.8%, p < 0.001). PLWH who received cART for ≤6 months had significantly lower CD4+ T-cell counts at lymphoma diagnosis than those who received cART for longer periods (p = 0.048). Additionally, the 5-year OS rate was better for PLWH who received cART for ≤6 months before lymphomas diagnosis than those who received cART for longer periods (64.5% vs. 51.9%, p = 0.114).

CONCLUSIONS

PLWH with DLBCL or BL had OS rates compatible to patients without HIV infection. Better outcomes for patients achieving CR to front-line therapy and those with shorter cART duration before lymphoma diagnosis suggest an underlying biological distinction in the lymphomas and the involvement of immunity, which warrants further studies.

Kaposi sarcoma herpesvirus/human herpesvirus 8-positive diffuse large B-cell lymphoma characterized by malignant ascites: A case report

Herein, we report a rare case of Kaposi sarcoma herpesvirus/human herpesvirus 8 (KSHV/HHV8)-positive diffuse large B-cell lymphoma (DLBCL), which is characterized by malignant ascites and complex karyotypes. A 72-year-old male patient who tested negative for human immunodeficiency virus presented with thrombocytopenia and lymphadenopathies. He was diagnosed with KSHV/HHV8-associated multicentric Castleman disease (MCD). After three years, he developed progressive lymphadenopathies and massive ascites. The lymphoma cells in the ascitic fluid presented with characteristic immunophenotype and monoclonality, which support the diagnosis of KSHV/HHV8-positive DLBCL. Lymphadenopathies and massive splenomegaly are common manifestations of KSHV/HHV8-positive DLBCL. Nevertheless, peritoneal involvement, as observed in this case, is a rare presentation. This emphasizes the diagnostic complexities of KSHV/HHV8-associated lymphoproliferative disorders. Within the context of preexisting KSHV/HHV8-associated multicentric Castleman disease, the differential diagnosis of this disorder can be challenging.

Primary Effusion Lymphoma Secondary to Human Herpesvirus 8 (HHV-8) Infection in an Immunocompetent Host: A Case Report

Primary effusion lymphoma (PEL) is a rare, aggressive, mature type of B-cell lymphoma that usually causes malignant, lymphomatous effusions in the absence of a solid mass. This is commonly seen in immunosuppressed individuals such as those with underlying malignancies, human immunodeficiency virus infection (HIV), cirrhosis, and a history of solid organ transplantation who are infected with human herpesvirus 8 (HHV-8). Clinical presentation varies depending on the extent of disease like shortness of breath, abdominal distention, and typical B symptoms like weight loss, fever, and night sweats. Morphological and immunohistochemical analysis of pleural fluid is required for diagnosis of PEL. Recent case studies are increasingly being reported with cases of PEL presenting in immunocompetent individuals infected with HHV-8. We present a case of PEL in an immunocompetent host and highlight its presentation, diagnosis, and management approaches. Due to the well-known association of PEL with immunocompromised status, the diagnosis is often overlooked in immunocompetent individuals. This case would further highlight the increasing association and the need for clinical vigilance in diagnosing PEL in immunocompetent patients.

Immune deficiency/dysregulation -associated lymphoproliferative disorders. Revised classification and management

Significant advances in the field of lymphoma have resulted in two recent classification proposals, the International Consensus Classification (ICC) and the 5th edition WHO. A few entities are categorized differently in the ICC compared to the WHO. Nowhere is this more apparent than the immunodeficiency lymphoproliferative disorders. The three previous versions of the WHO classification (3rd, 4th and revised 4th editions) and the ICC focused on four clinical settings in which these lesions arise for primary categorization. In contrast the 2023 WHO 5th edition includes pathologic characteristics including morphology and viral status, in addition to clinical setting, as important information for lesion classification. In addition, the 2023 WHO recognizes a broader number of clinical scenarios in which these lesions arise, including not only traditional types of immune deficiency but also immune dysregulation. With this classification it is hoped that new treatment strategies will be developed leading to better patient outcomes.

Extracavitary Primary Effusion Lymphoma Affecting the Oral Cavity: A Rare Case Report

Primary effusion lymphoma (PEL) is an aggressive neoplasm often diagnosed in immunosuppressed patients demonstrating peritoneal, pleural, or pericardial effusions. This high-grade lymphoma is strongly associated with human herpesvirus 8 (HHV8) infection and most of the lesions also show the presence of Epstein-Barr virus in tumor cells, which lacks CD20 expression and reveals a plasmablastic morphology and phenotype. The extracavitary or solid variant of PEL is even rarer and usually affects the lymph nodes and is currently considered a clinical manifestation of the classic PEL. In the oral cavity, extracavitary PEL is extremely rare and only a few patients have been previously reported, with no detailed clinicopathological description. The recognition of oral extracavitary PEL is even more important given the occurrence of plasmablastic lymphoma in the oral mucosa, which shares many clinical, microscopic, and phenotypic features with PEL, therefore, demanding from pathologists the search for HHV8, especially in immunosuppressed patients, and an appropriate clinical evaluation. In this report, we aim to describe a very rare extracavitary PEL affecting the palate of a 36-year-old patient and to review the literature regarding the extracavitary presentation of this aggressive lymphoma. This report demonstrates the importance of searching for HHV8 infection in oral lymphomas with plasmablastic features.

Epstein-Barr virus-associated lymphomas decoded

Epstein-Barr virus (EBV)-associated lymphomas cover a range of histological B- and T-cell non-Hodgkin and Hodgkin lymphoma subtypes. The role of EBV on B-cell malignant pathogenesis and its impact on the tumour microenvironment are intriguing but incompletely understood. Both the International Consensus Classification (ICC) and 5th Edition of the World Health Organization (WHO-HAEM5) proposals give prominence to the distinct clinical, prognostic, genetic and tumour microenvironmental features of EBV in lymphoproliferative disorders. There have been major advances in our biological understanding, in how to harness features of EBV and its host immune response for targeted therapy, and in using EBV as a method to monitor disease response. In this article, we showcase the latest developments and how they may be integrated to stimulate new and innovative approaches for further lines of investigation and therapy.

Rare diagnosis of an Epstein-Barr virus-positive extracavitary/solid variant of primary effusion lymphoma by duodenal endoscopic biopsy in a human immunodeficiency virus-seronegative and immunocompetent patient: A case report

Primary effusion lymphoma and its tissue-based subtype extracavitary/solid variant was first described in human immunodeficiency virus (HIV)-seropositive patients. We report the case of a 50-year-old HIV-seronegative male patient who presented with icterus and cholestasis. Computed tomography revealed a 80 × 56 mm abdominal mass. Fine-needle aspiration biopsy was performed from the celiac lymph nodes and pancreatic head, under endoscopic ultrasonography guidance. A duodenal endoscopic biopsy was taken from the infiltration area, and a core biopsy was performed for the portal hilar mass. All biopsies showed similar cytohistopathological features. LCA-positive lymphoid neoplasia had a plasmacytoid/anaplastic morphology and null cell phenotype. HHV-8 and Epstein-Barr virus-encoded small RNAs (EBER) were diffuse positive. The patient, who did not have an effusion, was diagnosed with an extracavitary/solid variant of primary effusion lymphoma. Virus-associated lymphoproliferative disorders should be considered in the differential diagnosis of patients without a history of immunosuppression or HIV infection.

Lymphomas with plasmablastic features: a report of the lymphoma workshop of the 20th meeting of the European Association for Haematopathology

Lymphomas with plasmablastic features are a heterogeneous group of aggressive and mostly uncommon neoplasms of varied aetiologies, presenting in immunocompetent individuals as well as in immunodeficiency, associated with EBV and Kaposi sarcoma virus infections, and some as progression from indolent B-cell lymphomas. They show overlapping diagnostic features and pose a differential diagnosis with other aggressive B-cell lymphomas that can downregulate the B-cell expression programme. The spectrum of rare reactive proliferations and all lymphomas defined by plasmablastic features, together with an expanding range of poorly characterised, uncommon conditions at the interface between reactive lymphoid proliferations and neoplasia submitted to the session V of the 20th European Association for Haematopathology/Society for Hematopathology lymphoma workshop are summarised and discussed in this paper.

Phenotypic and genotypic infidelity in B-lineage neoplasms, including transdifferentiation following targeted therapy: Report from the 2021 SH/EAHP Workshop

OBJECTIVES

Session 2 of the 2021 Society for Hematopathology and European Association for Haematopathology Workshop collected examples of lineage infidelity and transdifferentiation in B-lineage neoplasms, including after targeted therapy.

METHODS

Twenty cases were submitted. Whole-exome sequencing and genome-wide RNA expression analysis were available on a limited subsample.

RESULTS

A diagnosis of B-cell acute lymphoblastic leukemia (B-ALL) was rendered on at least 1 biopsy from 13 patients. There was 1 case of acute myeloid leukemia (AML); the remaining 6 cases were mature B-cell neoplasms. Targeted therapy was administered in 7 cases of B-ALL and 4 cases of mature B-cell neoplasms. Six cases of B-ALL underwent lineage switch to AML or mixed-phenotype acute leukemia at relapse, 5 of which had rearranged KMT2A. Changes in maturational state without lineage switch were observed in 2 cases. Examples of de novo aberrant T-cell antigen expression (n = 2) were seen among the mature B-cell lymphoma cohort, and their presence correlated with alterations in tumor cell gene expression patterns.

CONCLUSIONS

This cohort of cases enabled us to illustrate, discuss, and review current concepts of lineage switch and aberrant antigen expression in a variety of B-cell neoplasms and draw attention to the role targeted therapies may have in predisposing neoplasms to transdifferentiation as well as other, less expected changes in maturational status.

The role of viruses in HIV-associated lymphomas

Lymphomas are among the most common cancers in people with HIV (PWH). The lymphoma subtypes and pathogenesis of lymphoma in PWH are different from the immunocompetent population. It is well-known that HIV causes severe CD4+ T cell lymphopenia in the absence of antiretroviral therapy (ART); however, the risk of developing certain subtypes of lymphoma remains elevated even in people receiving ART with preserved CD4+ T cells. HIV contributes to lymphomagenesis and causes decreased immune surveillance via T cell depletion and dysregulation, B cell dysregulation, and the potential contribution of HIV-encoded proteins. The oncogenic gammaherpesviruses, Epstein-Barr virus (EBV) and Kaposi sarcoma herpesvirus (KSHV, also known as human herpesvirus 8), are the causative agents in the majority of HIV-associated lymphomas. HIV-associated T cell depletion and dysregulation allows EBV and KSHV to proliferate in infected B cells. Specific EBV- and KSHV-encoded proteins participate in B cell activation, and proliferation leading to B cell transformation. Understanding the distinct pathogenesis of HIV-associated lymphomas affords opportunities to develop therapies that specifically target these unique aspects and improve lymphoma outcomes in PWH. Agents being studied that target the specific roles of HIV, EBV, and KSHV in lymphomagenesis include immunotherapies, targeted agents, and cellular therapies.

HHV-8 associated lymphoma

PURPOSE OF REVIEW

The discovery of Kaposi sarcoma herpesvirus (KSHV) / human herpesvirus 8 (HHV-8) led to recognition of primary effusion lymphoma (PEL) as a distinct lymphoproliferative disorder. Subsequently, two other types of lymphoma have been shown to be associated with HHV-8 : HHV-8 positive diffuse large B cell lymphoma not otherwise specified and germinotropic lymphoproliferative disorder.The pathogenesis of PEL is unique as in most cases the HHV-8+ tumoral cells are coinfected with the Epstein-Barr virus (EBV), suggesting an interplay between these two herpesviruses. This article reviews advances in the field of characterization of the lymphomatous cells, pathogenesis, and targeted therapies.

RECENT FINDINGS

The gene expression profile analysis of PEL cells and the experimental coinfection of peripheral B cells with HHV-8 and EBV allow dissection of the mechanisms of lymphomagenesis and of the relative contribution of both viruses. Systemic chemotherapy regimen remains poorly effective but new therapeutic perspectives are open with the use of monoclonal antibodies, immunomodulatory drugs, and immunotherapy.

SUMMARY

HHV-8 associated lymphoma is a model for studying virus-induced lymphoproliferation and its relation with host immune response and PEL is a unique model to study the relative contribution of two herpesviruses to lymphomagenesis in coinfected cells.

SUMO Modification of Histone Demethylase KDM4A in Kaposi's Sarcoma-Associated Herpesvirus-Induced Primary Effusion Lymphoma

Primary effusion lymphoma (PEL) is a fatal B-cell lymphoma caused by Kaposi’s sarcoma-associated herpesvirus (KSHV) infection. Inducing KSHV lytic replication that causes the death of host cells is an attractive treatment approach for PE; however, combination therapy inhibiting viral production is frequently needed to improve its outcomes. We have previously shown that the KSHV lytic protein K-bZIP can SUMOylate histone lysine demethylase 4A (KDM4A) at lysine 471 (K471) and this SUMOylation is required for virus production upon KSHV reactivation. Here, we demonstrate that SUMOylation of KDM4A orchestrates PEL cell survival, a major challenge for the success of PEL treatment; and cell movement and angiogenesis, the cell functions contributing to PEL cell extravasation and dissemination. Furthermore, integrated ChIP-seq and RNA-seq analyses identified interleukin-10 (IL-10), an immunosuppressive cytokine, as a novel downstream target of KDM4A. We demonstrate that PEL-induced angiogenesis is dependent on IL-10. More importantly, single-cell RNA sequencing (scRNA-seq) analysis demonstrated that, at the late stage of KSHV reactivation, KDM4A determines the fates of PEL cells, as evidenced by two distinct cell populations; one with less apoptotic signaling expresses high levels of viral genes and the other is exactly opposite, while KDM4A-K417R-expressing cells contain only the apoptotic population with less viral gene expression. Consistently, KDM4A knockout significantly reduced cell viability and virus production in KSHV-reactivated PEL cells. Since inhibiting PEL extravasation and eradicating KSHV-infected PEL cells without increasing viral load provide a strong rationale for treating PEL, this study indicates targeting KDM4A as a promising therapeutic option for treating PEL.

IMPORTANCE PEL is an aggressive and untreatable B-cell lymphoma caused by KSHV infection. Therefore, new therapeutic approaches for PEL need to be investigated. Since simultaneous induction of KSHV reactivation and apoptosis can directly kill PEL cells, they have been applied in the treatment of this hematologic malignancy and have made progress. Epigenetic therapy with histone deacetylase (HDAC) inhibitors has been proved to treat PEL. However, the antitumor efficacies of HDAC inhibitors are modest and new approaches are needed. Following our previous report showing that the histone lysine demethylase KDM4A and its SUMOylation are required for lytic reactivation of KSHV in PEL cells, we further investigated its cellular function. Here, we found that SUMOylation of KDM4A is required for the survival, movement, and angiogenesis of lytic KSHV-infected PEL cells. Together with our previous finding showing the importance of KDM4A SUMOylation in viral production, KDM4A can be a potential therapeutic target for PEL.

HIV-Associated Lymphomas: Progress and New Challenges

The association of human immunodeficiency virus (HIV) and aggressive lymphomas was first reported in 1982. Before the development of effective HIV antiviral therapy, the incidence and the mortality of these lymphomas was high, with patients frequently succumbing to the disease. More lately, the combination of cART with chemoimmunotherapy significantly improved the survival outcome of the HIV-lymphomas. In this review, we discuss on describing the incidence of HIV-associated lymphomas, their clinical features, and the latest advances in the management of the various lymphoma subtypes.

A Comprehensive Clinicopathologic and Molecular Study of 19 Primary Effusion Lymphomas in HIV-infected Patients

Primary effusion lymphoma (PEL) is associated with human herpesvirus 8 and frequently with Epstein-Barr virus (EBV). We report here a single-center series of 19 human immunodeficiency virus-associated PELs, including 14 EBV+ and 5 EBV- PELs. The objectives were to describe the clinicopathologic features of PELs, with a focus on programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) expression, to search for genetic alterations by targeted deep sequencing analysis, and to compare the features between EBV+ and EBV- cases. All the patients were male, and the median age at diagnosis was 47 years old (interquartile range: 40 to 56 y). Reflecting the terminal B-cell differentiation, immunophenotypic profiles showed low expression levels of B-cell markers, including CD19 (0/19), CD20 (1/19), CD79a (0/19), PAX5 (1/19), BOB1 (3/19), and OCT2 (4/19), contrasting with a common expression of CD38 (10/19), CD138 (7/19), and IRF4/MUM1 (18/19). We observed a frequent aberrant expression of T-cell markers, especially CD3 (10/19), and less frequently CD2 (2/19), CD4 (3/19), CD5 (1/19), and CD8 (0/19). Only 2 cases were PD-L1 positive on tumor cells and none PD-1 positive. With respect to immune cells, 3 samples tested positive for PD-L1 and 5 for PD-1. Our 36-gene lymphopanel revealed 7 distinct variants in 5/10 PELs, with either a single or 2 mutations per sample: B2M (n=2), CD58 (n=1), EP300 (n=1), TNFAIP3 (n=1), ARID1A (n=1), and TP53 (n=1). Finally, we did not observe any major clinical, pathologic, or immunohistochemical differences between EBV+ and EBV- PELs and the outcome was similar (2-y overall survival probability of 61.9% [95% confidence interval, 31.2-82.1] vs. 60.0% [95% confidence interval, 12.6-88.2], respectively, P=0.62).

KSHV/HHV8-mediated hematologic diseases

Kaposi sarcoma (KS) herpesvirus (KSHV), also known as human herpesvirus 8, is the causal agent of KS but is also pathogenetically related to several lymphoproliferative disorders, including primary effusion lymphoma (PEL)/extracavitary (EC) PEL, KSHV-associated multicentric Castleman disease (MCD), KSHV+ diffuse large B-cell lymphoma, and germinotropic lymphoproliferative disorder. These different KSHV-associated diseases may co-occur and may have overlapping features. KSHV, similar to Epstein-Barr virus (EBV), is a lymphotropic gammaherpesvirus that is preferentially present in abnormal lymphoid proliferations occurring in immunecompromised individuals. Notably, both KSHV and EBV can infect and transform the same B cell, which is frequently seen in KSHV+ EBV+ PEL/EC-PEL. The mechanisms by which KSHV leads to lymphoproliferative disorders is thought to be related to the expression of a few transforming viral genes that can affect cellular proliferation and survival. There are critical differences between KSHV-MCD and PEL/EC-PEL, the 2 most common KSHV-associated lymphoid proliferations, including viral associations, patterns of viral gene expression, and cellular differentiation stage reflected by the phenotype and genotype of the infected abnormal B cells. Advances in treatment have improved outcomes, but mortality rates remain high. Our deepening understanding of KSHV biology, clinical features of KSHV-associated diseases, and newer clinical interventions should lead to improved and increasingly targeted therapeutic interventions.

Primary Effusion Lymphoma: A Clinicopathologic Perspective

Primary effusion lymphoma (PEL) is a rare, aggressive B-cell lymphoma that usually localizes to serous body cavities to subsequently form effusions in the absence of a discrete mass. Although some tumors can develop in extracavitary locations, the areas most often affected include the peritoneum, pleural space, and the pericardium. PEL is associated with the presence of human herpesvirus 8 (HHV8), also called the Kaposi sarcoma-associated herpesvirus (KSHV), with some variability in transformation potential suggested by frequent coinfection with the Epstein-Barr virus (EBV) (~80%), although the nature of the oncogenesis is unclear. Most patients suffering with this disease are to some degree immunocompromised (e.g., Human immunodeficiency virus (HIV) infection or post-solid organ transplantation) and, even with aggressive treatment, prognosis remains poor. There is no definitive guideline for the treatment of PEL, although CHOP-like regimens (cyclophosphamide, doxorubicin, vincristine, and prednisone) are frequently prescribed and, given the rarity of this disease, therapeutic focus is being redirected to personalized and targeted approaches in the experimental realm. Current clinical trials include the combination of lenalidomide and rituximab into the EPOCH regimen and the treatment of individuals with relapsed/refractory EBV-associated disease with tabelecleucel.

[HHV-8 Related immunological and hematological diseases]

HHV-8 is an oncogenic Gammaherpesvirinae discovered in 1994 during the HIV pandemic. It is the causative agent of Kaposi's sarcoma, and is also associated with the occurrence of several aggressive B lymphoproliferative disorders. Most of them occur in an immunosuppression setting, usually due to HIV infection. Multicentric HHV8-associated Castleman's disease and KSHV Inflammatory Cytokine Syndrome (KICS) are primarily reactive entities with prominent systemic features. They illustrate the cytokinic storm induced by HHV-8 in its cell host. On the other hand, HHV-8 can drive proliferation and lymphomagenesis of its plasmablastic cell host, and is associated with a risk to develop aggressive lymphomas with plasmacytic differenciation. Primary effusion lymphoma usually localizes in body cavities and may affect other extra-nodal sites ; its prognostic is poor. Diffuse large B-cell lymphoma HHV-8, NOS affect more commonly nodes and blood and evolve from infected cell of HHV-8 associated Castleman disease. On the contrary, germinotropic lymphoproliferative disorders presents mainly as localized adenopathy with indolent course, and show polyclonality. Histology plays a key role in distinguishing these different entities and need expert reviewing, especially since they may be associated with each other. Besides lymphoproliferative disorders, HHV8 is associated with various hematological manifestations. The aim of this review is to provide an update on the presentation, diagnosis, and management of immunologic and hematologic complications associated with HHV-8.

KSHV/HHV8-Associated Lymphoproliferative Disorders: Lessons Learnt from People Living with HIV

In 1992, Kaposi sarcoma herpesvirus (KSHV/HHV8) was discovered and identified as the causative agent for Kaposi sarcoma. Subsequently, the presence of this virus has been detected in a number of lymphoproliferative disorders in people living with HIV (PLWH), including: KSHV-associated multicentric Castleman disease, primary effusion lymphoma, KSHV-positive diffuse large B-cell lymphoma, and germinotropic lymphoproliferative disorder. Each of these rare entities has subsequently been diagnosed in HIV-negative individuals. The recognition of some of these KSHV/HHV8-associated lymphoproliferative disorders has led to their inclusion in the WHO classification of lymphomas in 2008 and the revision of 2016; however, further revision is under way to update the classification. The relatively recent recognition of these lymphoproliferative disorders and their low incidence, particularly in the HIV-negative population, means that there is little published evidence and consensus on their clinical features and management. The publication of a new WHO classification of lymphomas should yield diagnostic clarity, providing an impetus for retrospective case series and prospective clinical trials in these KSHV/HHV8-associated lymphoproliferative disorders.

Clinical and Therapeutic Implications of Epstein-Barr Virus in HIV-Related Lymphomas

The incidence of lymphomas is increased in people living with HIV (PLWH). Aggressive B-cell non-Hodgkin lymphomas (NHLs) are the most common and are considered an AIDS-defining cancer (ADC). Although Hodgkin lymphoma (HL) is not considered an ADC, its incidence is also increased in PLWH. Among all HIV-related lymphomas (HRL), the prevalence of Epstein-Barr virus (EBV) is high. It has been shown that EBV is involved in different lymphomagenic mechanisms mediated by some of its proteins, contributing to the development of different lymphoma subtypes. Additionally, cooperation between both HIV and EBV can lead to the proliferation of aberrant B-cells, thereby being an additional lymphomagenic mechanism in EBV-associated HRL. Despite the close relationship between EBV and HRL, the impact of EBV on clinical aspects has not been extensively studied. These lymphomas are treated with the same therapeutic regimens as the general population in combination with cART. Nevertheless, new therapeutic strategies targeting EBV are promising for these lymphomas. In this article, the different types of HRL are extensively reviewed, focusing on the influence of EBV on the epidemiology, pathogenesis, clinical presentation, and pathological characteristics of each lymphoma subtype. Moreover, novel therapies targeting EBV and future strategies to treat HRL harboring EBV are discussed.

What to Do for Increasing Cancer Burden on the African Continent? Accelerating Public Health Diagnostics Innovation for Prevention and Early Intervention on Cancers

No other place illustrates the increasing burden of cancer than in Africa and in particular, sub-Saharan Africa. Many of the individuals to be diagnosed with cancer will be in low-resource settings in the future due to, for example, an increase in populations and aging, and high co-morbidity with infections with viruses such as human immunodeficiency virus (HIV) and human papillomavirus (HPV), as well as the presence of infectious agents linked to cancer development. Due to lack of prevention and diagnostic innovation, patients present with advanced cancers, leading to poor survival and increased mortality. HIV infection-associated cancers such as B cell lymphomas, Kaposi's sarcoma, and HPV-associated cancers such as cervical cancer are particularly noteworthy in this context. Recent reports show that a host of other cancers are also associated with viral infection and these include lung, oral cavity, esophageal, and pharyngeal, hepatocellular carcinoma, and anal and vulvar cancers. This article examines the ways in which diagnostic innovation empowered by integrative biology and informed by public health priorities can improve cancer prevention or early intervention in Africa and beyond. In addition, I argue that because diagnostic biomarkers can often overlap with novel therapeutic targets, diagnostics research and development can have broader value for and impact on medical innovation.

[Human immunodeficiency virus and lymphoma]

Lymphomas remain a leading cause of morbidity and mortality for HIV-positive patients. The most common lymphomas include diffuse large B-cell lymphoma, Burkitt lymphoma, primary effusion lymphoma, plasmablastic lymphoma and Hodgkin lymphoma. Appropriate approach is determined by lymphoma stage, performans status, comorbidities, histological subtype, status of the HIV disease and immunosuppression. Treatment outcomes have improved due to chemotherapy modalities and effective antiretroviral therapy. This review summarizes epidemiology, pathogenesis, pathology, and current treatment landscape in HIV associated lymphoma.

Inhibition of polo-like kinase 1 (PLK1) facilitates reactivation of gamma-herpesviruses and their elimination

Both Kaposi's sarcoma-associated herpesvirus (KSHV) and Epstein-Barr virus (EBV) establish the persistent, life-long infection primarily at the latent status, and associate with certain types of tumors, such as B cell lymphomas, especially in immuno-compromised individuals including people living with HIV (PLWH). Lytic reactivation of these viruses can be employed to kill tumor cells harboring latently infected viral episomes through the viral cytopathic effects and the subsequent antiviral immune responses. In this study, we identified that polo-like kinase 1 (PLK1) is induced by KSHV de novo infection as well as lytic switch from KSHV latency. We further demonstrated that PLK1 depletion or inhibition facilitates KSHV reactivation and promotes cell death of KSHV-infected lymphoma cells. Mechanistically, PLK1 regulates Myc that is critical to both maintenance of KSHV latency and support of cell survival, and preferentially affects the level of H3K27me3 inactive mark both globally and at certain loci of KSHV viral episomes. Furthremore, we recognized that PLK1 inhibition synergizes with STAT3 inhibition to efficiently induce KSHV reactivation. We also confirmed that PLK1 depletion or inhibition yields the similar effect on EBV lytic reactivation and cell death of EBV-infected lymphoma cells. Lastly, we noticed that PLK1 in B cells is elevated in the context of HIV infection and caused by HIV Nef protein to favor KSHV/EBV latency.

Combined Inhibition of Akt and mTOR Is Effective Against Non-Hodgkin Lymphomas

Non-Hodgkin lymphoma (NHL) are a diverse group of hematological malignancies comprised of over 60 subtypes. These subtypes range from indolent to aggressive. The PI3K/Akt/mTOR pathway has been shown to contribute to cell survival and proliferation and is constitutively active in most NHL. MK-7075 (miransertib) and MK-4440 are small molecules that effectively inhibit Akt and have entered clinical development. Using in vitro and in vivo models of NHL, we explored targeting the kinase Akt with miransertib and MK-4440 alone or in combination with the mTORC1 inhibitor, rapamycin (sirolimus). Both Akt inhibitors inhibited the pathway and NHL proliferation in a subtype-dependent manner. However, these compounds had a minimal effect on the viability of primary B-cells. Importantly, the combination of miransertib and sirolimus synergistically reduced cell proliferation in NHL, including in one indolent subtype, e.g., follicular lymphoma (FL), and two aggressive subtypes, e.g., diffuse large B-cell lymphoma (DLBCL) and primary effusion lymphoma (PEL). To establish in vivo efficacy, we used several xenograft models of FL, DLBCL, and PEL. The results obtained in vivo were consistent with the in vitro studies. The FL xenograft was highly sensitive to the inhibition of Akt alone; however, the tumor burden of PEL xenografts was only significantly reduced when both Akt and mTORC1 were targeted. These data suggest that targeting the PI3K/Akt/mTOR pathway with Akt inhibitors such as miransertib in combination with mTOR inhibitors serves as a broadly applicable therapeutic in NHL.

HIV Lymphoma and Burkitts Lymphoma

Despite widely available antiretroviral therapy, lymphoma remains the leading cause of death for human immunodeficiency virus (HIV)-infected persons in economically developed countries. Even a few months of drug interruptions can lead to drops in the CD4 cell count, HIV viremia, and an increased risk of lymphoma. Currently, good HIV control facilitates intensive therapies appropriate to the lymphoma, including autologous and even allogeneic hematopoietic stem cell transplantation. Nonetheless, HIV-related lymphomas have unique aspects, including pathogenetic differences driven by the presence of HIV and often coinfection with oncogenic viruses. Future therapies might exploit these differences. Lymphoma subtypes also differ in the HIV-infected population, and the disease has a higher propensity for advanced-stage, aggressive presentation and extranodal disease. Other unique aspects include the need to avoid potential interactions between antiretroviral therapy and chemotherapeutic agents and the need for HIV-specific supportive care such as infection prophylaxis. Overall, the care of these patients has progressed sufficiently that recent guidelines from the American Society of Clinical Oncology advocate the inclusion of HIV-infected patients alongside HIV-negative patients in cancer clinical trials when appropriate. This article examines HIV lymphoma and includes Burkitt lymphoma in the general population.

Rare EBV-associated B cell neoplasms of the gastrointestinal tract

EBV-driven B cell neoplasms can rarely present as an extranodal mass in the gastrointestinal tract and can be missed, even by experienced pathologists, because of this uncommon presentation. A selection of these neoplasms, namely EBV-positive diffuse large B cell lymphoma, not otherwise specified (DLBCL NOS), EBV-positive mucocutaneous ulcer (EBV MCU), extracavitary primary effusion lymphoma (EPEL), and EBV-positive Burkitt lymphoma, will be discussed in the present review. Besides the common thread of EBV positivity, these lymphoproliferative disorders arise in unique clinical settings that are often associated with immunodeficiency, immunosuppression or immunosenescence and can present as solitary masses albeit rarely, within the gastrointestinal tract.

Panniculitis-Like Presentation of Extracavitary Primary Effusion Lymphoma

Primary effusion lymphoma (PEL) is defined as a HHV-8-associated large B-cell lymphoma, which favors HIV-infected young adults, typically presenting as a serous (pleural, pericardial, or peritoneal) effusion with no identifiable tumor mass. Uncommon instances of lymphoid proliferations with the same morphology, immunophenotype, and molecular features as PEL, but occurring as a solid tumor mass without serous cavities involvement, have been termed extracavitary (or solid) variant of PEL. We hereby report the exceptional case of a HIV-associated extracavitary PEL primarily localized to the skin and exhibiting a panniculitis-like presentation. Primary cutaneous presentation of extracavitary PEL is exceedingly uncommon, with only 6 cases previously described in the literature. In light of its atypical immunophenotype, the differential diagnosis in case of skin involvement by extracavitary PEL is challenging: demonstration of HHV-8 infection in neoplastic cells is of pivotal importance. Our case is further atypical in that the lymphoid proliferation underwent complete and protracted regression solely by establishment of highly active antiretroviral therapy.

Primary Effusion Lymphoma: A Clinicopathological Study of 70 Cases

Simple Summary

Primary effusion lymphoma (PEL) is a rare HHV8 driven large B-cell lymphoma. It is often associated with HIV infection and seldom occurs in HIV-negative immunocompromised patients. Patients with PEL usually present with effusion only, but occasionally with an extracavitary mass, or both. This retrospective study aimed to better characterize the clinicopathological features of PEL by comparing effusion-only PEL versus the extracavitary-only PEL and HIV-positive versus HIV-negative cases in a large cohort of 70 patients. All 70 (100%) cases were positive for HHV8. Fifty-six (80%) patients had HIV infection. Patients presenting with effusion only versus extracavitary disease were associated with different clinicopathologic features. After a median follow-up time of 40 months (range 0–96), 26 of 52 (50%) patients with clinical follow-up died, and the median survival was 42.5 months. PEL is an aggressive lymphoma with a poor prognosis, regardless of extracavitary presentation or HIV status.

Abstract

Primary effusion lymphoma (PEL) is a rare type of large B-cell lymphoma associated with human herpesvirus 8 (HHV8) infection. Patients with PEL usually present with an effusion, but occasionally with an extracavitary mass. In this study, we reported a cohort of 70 patients with PEL: 67 men and 3 women with a median age of 46 years (range 26–91). Of these, 56 (80%) patients had human immunodeficiency virus (HIV) infection, eight were HIV-negative, and six had unknown HIV status. Nineteen (27%) patients had Kaposi sarcoma. Thirty-five (50%) patients presented with effusion only, 27 (39%) had an extracavitary mass or masses only, and eight (11%) had both effusion and extracavitary disease. The lymphoma cells showed plasmablastic, immunoblastic, or anaplastic morphology. All 70 (100%) cases were positive for HHV8. Compared with effusion-only PEL, patients with extracavitary-only PEL were younger (median age, 42 vs. 52 years, p = 0.001), more likely to be HIV-positive (88.9% vs. 68.6%, p = 0.06) and EBV-positive (76.9% vs. 51.9%, p = 0.06), and less often positive for CD45 (69.2% vs. 96.2%, p = 0.01), EMA (26.7% vs. 100%, p = 0.0005), and CD30 (60% vs. 81.5%, p = 0.09). Of 52 (50%) patients with clinical follow-up, 26 died after a median follow-up time of 40.0 months (range 0–96), and the median overall survival was 42.5 months. The median OS for patients with effusion-only and with extracavitary-only PEL were 30.0 and 37.9 months, respectively (p = 0.34), and patients with extracavitary-only PEL had a lower mortality rate at the time of last follow-up (35% vs. 61.5%, p = 0.07). The median OS for HIV-positive and HIV-negative patients were 42.5 and 6.8 months, respectively (p = 0.57), and they had a similar mortality rate of 50% at last follow-up. In conclusion, patients presenting with effusion-only versus extracavitary-only disease are associated with different clinicopathologic features. PEL is an aggressive lymphoma with a poor prognosis, regardless of extracavitary presentation or HIV status.

Primary Pulmonary B-Cell Lymphoma: A Review and Update

Simple Summary

The group of B-cell lymphomas primarily involving the lung encompasses different histological entities with distinct biological aspects, while sharing some clinical and radiological features related to their common anatomic site of occurrence. Recent molecular advances in the molecular genetics of these lesions have substantially improved of our understanding of the mechanisms of lymphomagenesis, adding novel information to histology in order to better characterize and manage these diseases. This review summarizes the available clinical, radiological, pathological, and molecular data on primary pulmonary B-cell lymphomas, discusses the mechanisms of lymphomagenesis, and highlights the role of a multi-disciplinary management in overcoming the diagnostic and therapeutic challenges in this setting.

Abstract

Primary pulmonary B-cell lymphomas (PP-BCLs) comprise a group of extranodal non-Hodgkin lymphomas of B-cell origin, which primarily affect the lung without evidence of extrapulmonary disease at the time of diagnosis and up to 3 months afterwards. Primary lymphoid proliferations of the lung are most often of B-cell lineage, and include three major entities with different clinical, morphological, and molecular features: primary pulmonary marginal zone lymphoma of mucosa-associated lymphoid tissue (PP-MZL, or MALT lymphoma), primary pulmonary diffuse large B cell lymphoma (PP-DLBCL), and lymphomatoid granulomatosis (LYG). Less common entities include primary effusion B-cell lymphoma (PEL) and intravascular large B cell lymphoma (IVLBCL). A proper workup requires a multidisciplinary approach, including radiologists, pneumologists, thoracic surgeons, pathologists, hemato-oncologists, and radiation oncologists, in order to achieve a correct diagnosis and risk assessment. Aim of this review is to analyze and outline the clinical and pathological features of the most frequent PP-BCLs, and to critically analyze the major issues in their diagnosis and management.

Hodgkin Reed-Sternberg-Like Cells in Non-Hodgkin Lymphoma

Reed-Sternberg cells (RSCs) are hallmarks of classic Hodgkin lymphoma (cHL). However, cells with a similar morphology and immunophenotype, so-called Reed-Sternberg-like cells (RSLCs), are occasionally seen in both B cell and T cell non-Hodgkin Lymphomas (NHLs). In NHLs, RSLCs are usually present as scattered elements or in small clusters, and the typical background microenviroment of cHL is usually absent. Nevertheless, in NHLs, the phenotype of RSLCs is very similar to typical RSCs, staining positive for CD30 and EBV, and often for B cell lineage markers, and negative for CD45/LCA. Due to different therapeutic approaches and prognostication, it is mandatory to distinguish between cHL and NHLs. Herein, NHL types in which RSLCs can be detected along with clinicopathological correlation are described. Moreover, the main helpful clues in the differential diagnosis with cHL are summarized.

Clinical and pathological features of Kaposi sarcoma herpesvirus-associated inflammatory cytokine syndrome

: Kaposi sarcoma Herpesvirus (KSHV)-associated inflammatory cytokine syndrome (KICS) is an uncommon but aggressive human Kaposi sarcoma herpesvirus associated disorder that is mostly reported in people living with HIV. The diagnosis of KICS is based on clinical criteria, and, in contrast to other KSHV-related malignancies, characteristic pathological features have not yet been described. We report novel clinical and pathological features in an HIV-1 infected patient diagnosed with KICS.

Developing new ceramide analogs and identifying novel sphingolipid-controlled genes against a virus-associated lymphoma

Primary effusion lymphoma (PEL) is an aggressive malignancy with poor prognosis even under chemotherapy. Kaposi sarcoma-associated herpesvirus (KSHV), one of the human oncogenic viruses, is the principal causative agent. Currently, there is no specific treatment for PEL; therefore, developing new therapies is of great importance. Sphingolipid metabolism plays an important role in determining the fate of tumor cells. Our previous studies have demonstrated that there is a correlation between sphingolipid metabolism and KSHV+ tumor cell survival. To further develop sphingolipid metabolism-targeted therapy, after screening a series of newly synthesized ceramide analogs, here, we have identified compounds with effective anti-PEL activity. These compounds induce significant PEL apoptosis, cell-cycle arrest, and intracellular ceramide production through regulation of ceramide synthesizing or ceramide metabolizing enzymes and dramatically suppress tumor progression without visible toxicity in vivo. These new compounds also increase viral lytic gene expression in PEL cells. Our comparative transcriptomic analysis revealed their mechanisms of action for inducing PEL cell death and identified a subset of novel cellular genes, including AURKA and CDCA3, controlled by sphingolipid metabolism, and required for PEL survival with functional validation. These data provide the framework for the development of promising sphingolipid-based therapies against this virus-associated malignancy.

Extracavitary primary effusion lymphoma recurring with syphilis in an HIV-infected patient

A 59-year-old Caucasian man infected with HIV, in remission from human herpes virus-8-positive extracavitary primary effusion lymphoma (EC-PEL), presented to a sexual health clinic with fever and rectal pain 10 weeks after a single episode of receptive anal sexual intercourse with another man. He was initially treated for a presumptive diagnosis of lymphogranuloma venereum proctitis, then for syphilis on positive serology. Rectosigmoidoscopy revealed a single ulcerated rectal mass; endoscopic biopsies confirmed the recurrence of EC-PEL. The patient received chemotherapy and went into remission. This is the first reported case of EC-PEL occurring synchronously with early syphilis, and specifically at the site of inoculation, which can be a major diagnostic challenge since both conditions may present with lymphadenopathy, mucosal involvement and constitutional symptoms. We reviewed the literature for similar cases and hypothesised that syphilis may have triggered the recurrence of this rare lymphoma.

The Changing Landscape of Lymphoma Associated with HIV Infection

Purpose of Review

Cancer remains a major cause of morbidity and mortality in HIV-infected individuals, with aggressive non-Hodgkin’s lymphoma as the most frequent one. However, the introduction of modern antiretroviral therapy (ART) drastically improved treatment options and prognosis in HIV-associated lymphomas. This review summarized the current treatment landscape and future challenges in HIV-positive patients with non-Hodgkin’s and Hodgkin’s lymphoma.

Recent Findings

Selecting the appropriate therapy for the individual patient, diffuse-large B cell lymphoma, Burkitt’s lymphoma, and Hodgkin’s disease may be curable diseases. In contrast, the prognosis of plasmablastic lymphoma and primary effusion lymphoma remain poor. New treatment approaches, as targeted therapies or CAR T cell therapy, may broaden the therapeutic armamentarium.

Summary

The continuous application of ART is mandatory for successful treatment. The choice of lymphoma therapy may follow the recommendations for HIV-negative patients, but prospective trials in HIV-lymphoma are needed.