Primary effusion lymphoma after heart transplantation: a new entity associated with human herpesvirus-8

A Pathology Experience of Posttransplant Lymphoproliferative Disorder From One Tertiary Hospital: Pathology Concepts and Diagnostic Approach

BACKGROUND

Solid organ transplantation and bone marrow/hematologic stem cell transplantation recipients face a heightened risk of developing malignancies or cancer as a result of immunosuppression. Posttransplant lymphoproliferative disorders (PTLD) are a range of disorders from benign lymphoid growth to lymphoma found post-transplant. Risk factors for PTLD include high immunosuppressive use and oncogenic effects of Epstein-Barr virus (EBV). There is a lack of comprehensive clinical and pathological documentation of PTLD cases among Saudi patients, and the available data are limited to a few case reports. As a result, a deeper understanding of this disease requires more clinicopathological information.

MATERIAL AND METHOD

In this review, we share our insights on cases diagnosed with PTLD at King Faisal Specialist Hospital and Research Center, a prominent tertiary center in the western region of Saudi Arabia, from 2005-2023.

RESULT

We have diagnosed a total of 14 cases of PTLD in our department, with an age range spanning from 3 to 62 years. These diagnoses were made based on biopsies or tumor resection procedures. The survival rate of patients is believed to be influenced by multiple factors, including histology, tumorigenesis, disease biology, and clinical stage. Additionally, Kaplan-Meier curve analysis indicates that female patients tend to have a higher estimated survival rate compared to males.

CONCLUSION

PTLD diagnosis and therapy have greatly improved in the past 20 years. PTLD is treated with reduced immunosuppression, rituximab, chemotherapy, adoptive therapy, surgery, antiviral therapy, and radiotherapy. In this study, we present our experience from a large tertiary center in the western region of Saudi Arabia. Moreover, we will go through etiology, clinical features, and pathologic morphology along with the corresponding genetics, prevention, and valid treatment options.

A Case of Epstein-Barr Virus-Negative Post-transplant Lymphoproliferative Disorder in a Solid Organ Transplant Recipient With Untreated Chronic Hepatitis C

Post-transplant lymphoproliferative disorder (PTLD) is one of the most common malignancies affecting solid organ transplant recipients. The disease is frequently associated with Epstein-Barr virus (EBV) infection (70% of cases) and cases are often delineated by EBV positivity status. The oncogenesis of EBV-positive PTLD is well-described in the literature; however, the etiology of the EBV-negative subtype is poorly understood. This report describes a case of EBV-negative PTLD developing in a combined kidney-pancreas transplant recipient with an incidental finding of untreated chronic hepatitis C virus (HCV). Our experience suggests an association between HCV and EBV-negative PTLD. Additional well-designed studies are needed to further investigate this association.

Post-Transplant Lymphoproliferative Disorders

Post-transplant lymphoproliferative disorders (PTLDs) are a heterogenous set of unregulated lymphoid cell proliferations after organ or tissue transplant. A majority of cases are associated with the Epstein-Barr virus and higher intensity of pharmacologic immunosuppression. The clinical presentations are numerous. The diagnosis is ideally by histology, except in cases where the tumor is inaccessible to biopsy. While some pre-emptive therapies and treatment strategies are available have reasonable success are available, they do not eliminate the high morbidity and significant mortality after PTLD.

From the archives of MD Anderson Cancer Center: Primary effusion lymphoma with simultaneous involvement of the retroperitoneum and pleural cavity

Primary effusion lymphoma (PEL) is a rare neoplasm that arises in the context of severe immunosuppression. Acquired immunodeficiency syndrome (AIDS) as a result of human immunodeficiency virus (HIV) infection is the most common cause of immunodeficiency in patients who develop PEL. These neoplasms usually involve one or more body cavities, so-called classic PEL. The pleural cavity is most often involved, followed by the peritoneal and pericardial cavities. Involvement of the cerebrospinal fluid (CSF) and meninges is rare. A subset of patients can present with a tissue-based mass, known as the extracavitary variant. We encountered a patient with HIV infection and severe immunosuppression who presented initially with mediastinal, retroperitoneal mass and bilateral pleural effusions. He subsequently developed CSF involvement. Despite therapy, the patient relapsed with chest wall disease 6 months later and died shortly thereafter. Our literature review yielded about 400 cases of PEL reported previously. About 65 % of PEL patients have had AIDS, but a subset of patients had immunosuppression attributable to organ transplantation or physiological immunosenescence. CSF involvement has been reported in ~2 % of patients, and about 10 % of patients had both body cavity and extracavitary disease. The pathologic findings in this case were typical of extracavitary PEL. The neoplastic cells had features of plasmablasts and were positive for HHV-8, Epstein-Barr virus encoded RNA (EBER) and plasma cell associated markers, and were negative for B-cell antigens. The prognosis of patients with PEL is usually poor with a median survival less than one year in most studies. We use this patient's case as an illustration of PEL and we review the clinicopathologic findings and differential diagnosis of PEL.

Cancers associated with human gammaherpesviruses

Epstein-Barr virus (EBV; human herpesvirus 4; HHV-4) and Kaposi sarcoma-associated herpesvirus (KSHV; human herpesvirus 8; HHV-8) are human gammaherpesviruses that have oncogenic properties. EBV is a lymphocryptovirus, whereas HHV-8/KSHV is a rhadinovirus. As lymphotropic viruses, EBV and KSHV are associated with several lymphoproliferative diseases or plasmacytic/plasmablastic neoplasms. Interestingly, these viruses can also infect epithelial cells causing carcinomas and, in the case of KSHV, endothelial cells, causing sarcoma. EBV is associated with Burkitt lymphoma, classic Hodgkin lymphoma, nasopharyngeal carcinoma, plasmablastic lymphoma, lymphomatoid granulomatosis, leiomyosarcoma, and subsets of diffuse large B-cell lymphoma, post-transplant lymphoproliferative disorder, and gastric carcinoma. KSHV is implicated in Kaposi sarcoma, primary effusion lymphoma, multicentric Castleman disease, and KSHV-positive diffuse large B-cell lymphoma. Pathogenesis by these two herpesviruses is intrinsically linked to viral proteins expressed during the lytic and latent lifecycles. This comprehensive review intends to provide an overview of the EBV and KSHV viral cycles, viral proteins that contribute to oncogenesis, and the current understanding of the pathogenesis and clinicopathology of their related neoplastic entities.

Primary Effusion Lymphoma Presenting As Parapneumonic Pleural Effusion

Primary effusion lymphoma (PEL) is a rare form of high-grade non-Hodgkin's lymphoma that usually occurs in patients with compromised immunity or human immunodeficiency virus (HIV) infection. PEL is a B-cell lymphoma that principally presents as effusions without a tumor mass. We present a case of a 56-year-old African-American male with a medical history of HIV admitted to the hospital with right lung lower lobe pneumonia and parapneumonic effusion. Thoracentesis and pleural fluid cytology led to the diagnosis of PEL. He received treatment with chemotherapy and antiretroviral therapy (ART). The emphasis is to investigate immunocompromised patients presenting with pleural effusion for PEL, as it is a rare ailment with a high mortality rate.

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.

Identification of Differentially Expressed Human Endogenous Retrovirus Families in Human Leukemia and Lymphoma Cell Lines and Stem Cells

Endogenous retroviruses (ERVs) are becoming more and more relevant in cancer research and might be potential targets. The oncogenic potential of human ERVs (HERVs) has been recognized and includes immunosuppression, cell fusion, antigenicity of viral proteins, and regulation of neighboring genes. To decipher the role of HERVs in human cancers, we used a bioinformatics approach and analyzed RNA sequencing data from the LL-100 panel, covering 22 entities of hematopoietic neoplasias including T cell, B cell and myeloid malignancies. We compared HERV expression in this panel with hematopoietic stem cells (HSCs), embryonic stem cells (ESCs) and normal blood cells. RNA sequencing data were mapped against a comprehensive synthetic viral metagenome with 116 HERV sequences from 14 different HERV families. Of these, 13 HERV families and elements were differently expressed in malignant hematopoietic cells and stem cells. We found transcriptional upregulation of HERVE family in acute megakaryocytic and erythroid leukemia and of HERVFc family in multiple myeloma/plasma cell leukemia (PCL). The HERVFc member HERVFc-1 was found transcriptionally active in the multiple myeloma cell line OPM-2 and also in the Hodgkin lymphoma cell line L-428. The expression of HERVFc-1 in L-428 cells was validated by qRT-PCR. We also confirm transcriptional downregulation of ERV3 in acute megakaryocytic and erythroid leukemia, and HERVK in acute monocytic and myelocytic leukemia and a depression of HERVF in all malignant entities. Most of the higher expressed HERV families could be detected in stem cells including HERVK (HML-2), HERV-like, HERVV, HERVT, ERV9, HERVW, HERVF, HERVMER, ERV3, HERVH and HERVPABLB.

Primary effusion lymphoma occurring in the setting of transplanted patients: a systematic review of a rare, life-threatening post-transplantation occurrence

BACKGROUND

Primary effusion lymphoma is a rare, aggressive large B-cell lymphoma strictly linked to infection by Human Herpes virus 8/Kaposi sarcoma-associated herpes virus. In its classic form, it is characterized by body cavities neoplastic effusions without detectable tumor masses. It often occurs in immunocompromised patients, such as HIV-positive individuals. Primary effusion lymphoma may affect HIV-negative elderly patients from Human Herpes virus 8 endemic regions. So far, rare cases have been reported in transplanted patients. The purpose of our systematic review is to improve our understanding of this type of aggressive lymphoma in the setting of transplantation, focusing on epidemiology, clinical presentation, pathological features, differential diagnosis, treatment and outcome. The role of assessing the viral serological status in donors and recipients is also discussed.

METHODS

We performed a systematic review adhering to the PRISMA guidelines. The literature search was conducted on PubMed/MEDLINE, Web of Science, Scopus, EMBASE and Cochrane Library, using the search terms "primary effusion lymphoma" and "post-transplant".

RESULTS

Our search identified 13 cases of post-transplant primary effusion lymphoma, predominantly in solid organ transplant recipients (6 kidney, 3 heart, 2 liver and 1 intestine), with only one case after allogenic bone marrow transplantation. Long-term immunosuppression is important in post-transplant primary effusion lymphoma commonly developing several years after transplantation. Kaposi Sarcoma occurred in association with lymphoma in 4 cases of solid organ recipients. The lymphoma showed the classical presentation with body cavity effusions in absence of tumor masses in 10 cases; 2 cases presented as solid masses, lacking effusions and one case as effusions associated with multiple organ involvement. Primary effusion lymphoma occurring in the setting of transplantation was more often Epstein Barr-virus negative. The prognosis was poor. In addition to chemotherapy, reduction of immunosuppressive treatment, was generally attempted.

CONCLUSIONS

Primary effusion lymphoma is a rare, but often fatal post-transplant complication. Its rarity and the difficulty in achieving the diagnosis may lead to miss this complication. Clinicians should suspect primary effusion lymphoma in transplanted patients, presenting generally with unexplained body cavity effusions, although rare cases with solid masses are described.

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.

Primary effusion lymphoma in human immune deficiency (HIV)-negative non-organ transplant immunocompetent patients

Primary effusion lymphoma (PEL) is a rare non‐Hodgkin's lymphoma most commonly occurring in the context of human immune deficiency (HIV) infection. Herpes virus 8 (HHV‐8) has been associated with PEL and considered to be the etiologic agent. In addition, most cases (60%‐90%) also show evidence of Epstein‐Barr virus (EBV) infection. We describe here an elderly man who was HIV seronegative and immunocompetent, and presented with worsening weakness and ascites. The diagnosis of PEL was rendered cytologically and supported by the results of flow cytometry. The presence of HHV‐8 was demonstrated by immunohistochemistry, whereas EBV‐associated genetic material was absent by EBER ISH. No lymphadenopathy or organ involvement with lymphoma was found. Systemic chemotherapy with lenalidomide was started given the poor prognosis and commodities of severe coronary artery disease; however, the patient did not respond and succumbed to his disease in 4 months. We present detailed cytologic and clinical findings of this very rare occurrence, and review literature of all reported PEL cases of HIV‐negative, nontransplant, immunocompetent patients.

The Diagnosis of Pleural Tumors Other Than Mesothelioma

CONTEXT

- Pleural pathology has been dominated by discussions relating to the diagnosis, prognosis, etiology, and management of malignant mesothelioma. However, there exists a diverse group of other neoplasms that involve the pleura; the most common by far is metastatic carcinoma, usually of pulmonary origin. Other metastatic tumors of varied histogenesis do occur but are less common. Primary pleural neoplasms other than diffuse malignant mesothelioma are either uncommon or rare and have received less attention.

OBJECTIVE

- To provide a review of those diverse tumors that can involve the pleura other than mesothelioma in order to facilitate their accurate diagnosis.

DATA SOURCES

- Review of relevant literature published via PubMed and other search engines.

CONCLUSIONS

- A wide variety of tumors can involve the pleura. In most cases, the approach of considering the morphologic features with appropriate immunohistochemistry, in the correct clinical context, allows for a confident diagnosis. For a number of those soft tissue tumors that are well recognized in the pleura, such as solitary fibrous tumor, desmoid-type fibromatosis, synovial sarcoma, and epithelioid hemangioendothelioma, novel markers now exist based on an understanding of the individual tumors' molecular characteristics. Primary pleural lymphomas are rare with poor prognosis. They represent localized specific diffuse large B-cell lymphomas, with either post-germinal center B-cell or plasma cell lineage, arising in the context of either immunodeficiency or immune sequestration and with viral infection.

Biology and management of primary effusion lymphoma

Primary effusion lymphoma (PEL) is a rare B-cell malignancy that most often occurs in immunocompromised patients, such as HIV-infected individuals and patients receiving organ transplantation. The main characteristic of PEL is neoplastic effusions in body cavities without detectable tumor masses. The onset of the disease is associated with latent infection of human herpes virus 8/Kaposi sarcoma–associated herpes virus, and the normal counterpart of tumor cells is B cells with plasmablastic differentiation. A condition of immunodeficiency and a usual absence of CD20 expression lead to the expectation of the lack of efficacy of anti-CD20 monoclonal antibody; clinical outcomes of the disease remain extremely poor, with an overall survival at 1 year of ∼30%. Although recent progress in antiretroviral therapy has improved outcomes of HIV-infected patients, its benefit is still limited in patients with PEL. Furthermore, the usual high expression of programmed death ligand 1 in tumor cells, one of the most important immune-checkpoint molecules, results in the immune escape of tumor cells from the host immune defense, which could be the underlying mechanism of poor treatment efficacy. Molecular-targeted therapies for the activating pathways in PEL, including NF-κB, JAK/STAT, and phosphatidylinositol 3-kinase/AKT, have emerged to treat this intractable disease. A combination of immunological recovery from immune deficiency, overcoming the immune escape, and the development of more effective drugs will be vital for improving the outcomes of PEL patients in the future.

Primary effusion lymphoma of the pleural space: Report of a rare complication of cardiac transplant with review of the literature

Primary effusion lymphoma (PEL) is a rare mature B-cell non-Hodgkin's lymphoma arising in body cavities and presenting with effusions. It has been described predominantly in patients with impaired immunity from the acquired immunodeficiency syndrome and is associated with the Human Herpesvirus-8 (HHV-8). Seldom has PEL been diagnosed in persons negative for the human immunodeficiency virus (HIV), and in such cases it has occurred primarily in the setting of posttransplant immunosuppression. We report an instructive case of a Caribbean-American HIV-negative orthotopic heart transplant recipient with a history of HHV-8-associated Kaposi's sarcoma who developed HHV-8 viremia and PEL of the pleural space early in the posttransplant course. This case highlights the importance of considering PEL in the differential diagnosis of a new pleural effusion in a transplant recipient at risk for HHV-8-associated disease.

Cardiac Hematological Malignancies: Typical Growth Patterns, Imaging Features, and Clinical Outcome

Cardiac hematological malignancies (CHMs) are rare entities and comprise lymphoma, leukemic infiltration, and extramedullary manifestation of multiple myeloma. The aim of this work is to summarize typical growth patterns, imaging features, and outcome parameters of CHM. Overall, 12 cases from 4 centers were reviewed retrospectively together with 604 cases from the literature. Cardiac hematological malignancies were mainly represented by B-cell lymphoma (70.0%). Other entities were rarer. Almost half of the patients showed involvement of multiple cardiac structures. Most commonly right atrium, right ventricle, pericardium, left atrium, and left ventricle were affected in decreased order of frequency. Cardiac hematological malignancies manifested with 3 growth patterns: intracaval masses, heart wall infiltration, and pericardial effusion. Several subtypes of CHM tended to present with different patterns. Clinical presentation is unspecific-frequent signs were dyspnea (54.6%), arrhythmias (30.5%), and thoracic pain (18.5%). Outcome of CHM is poor with mean survival of 283.6 days for leukemias, 260.1 days for T-cell non-Hodgkin lymphoma (NHL), 217.9 days for B-cell NHL, and 155.5 days for multiple myeloma.

Donor Monoclonal Gammopathy May Cause Lymphoproliferative Disorders in Solid Organ Transplant Recipients

Prior research on donor monoclonal gammopathy of undetermined significance (MGUS) has been inadequate regarding the risk for lymphoproliferative disease in solid organ transplantation recipients. Seven organ recipients from two different donors developed lymphoproliferative disease. The origin of the malignancy was determined by use of microsatellite analysis, and the plasma of the two donors was analyzed with the use of electrophoresis. The clinical courses of the seven recipients were followed for 36-60 months. One donor transmitted lymphoplasmacytic lymphoma to two kidney recipients and MGUS to a liver recipient, all IgMκ. A second donor caused IgGλ myeloma in two kidney and one liver recipient, and IgGλ gammopathy in a heart recipient. Transplant nephrectomy was performed in three kidney recipients and remission was achieved. The fourth kidney recipient has kept the graft and the disease has progressed. The liver recipient died from myeloma. There were no clinical signs of lymphoproliferative disease in the donors, but retrospective serum analyses showed M-components, IgMκ (37 g/L) and IgGλ (8 g/L). Donors with MGUS may cause donor-transmitted malignancies via passenger lymphocytes/plasma cells in solid organ recipients. The results call for a large register study of the incidence of donor MGUS and lymphoproliferative disease in their recipients.

Role of Epstein-Barr virus status and immunophenotypic studies in the evaluation of exfoliative cytology specimens from patients with post-transplant lymphoproliferative disorders

BACKGROUND

Post-transplant lymphoproliferative disorders (PTLDs) are well characterized in tissue sections, but their evaluation in exfoliative cytology specimens is limited. This study reports a 25-year experience with PTLDs in exfoliative cytology specimens.

METHODS

All solid organ or allogeneic stem cell transplant recipients with PTLDs and exfoliative cytology specimens from 1987 to 2011 were identified. The cytomorphology, Epstein-Barr virus (EBV) status, flow cytometry, immunohistochemistry, and molecular studies were reviewed from all exfoliative cytology specimens previously diagnosed as atypical lymphoid proliferations or PTLDs.

RESULTS

A total of 55 patients (age range, 1-72 years) with PTLDs had 434 exfoliative cytology specimens. Thirty-six of the 55 patients (65%) had 54 specimens with abnormal lymphoid proliferations (12% of the specimens), and 26 of these patients had 37 specimens available for review (15 cerebrospinal fluid specimens, 12 peritoneal fluid specimens, 9 pleural fluid specimens, and 1 bronchoalveolar lavage fluid specimen). Thirty percent of the reviewed cytology specimens were diagnostic of PTLDs, including 8 cases of monomorphic post-transplant lymphoproliferative disorder (M-PTLD) with abnormal B/T-cell populations identified with flow cytometry/immunohistochemistry and 3 EBV-positive specimens with a differential diagnosis of polymorphic PTLD versus M-PTLD. All cases diagnostic of a PTLD had 1 to 3 ancillary studies performed. Forty percent of the cytology specimens (15 of 37) were suspicious for a PTLD, but ancillary studies were performed for only a third of them, and they did not support a definitive diagnosis of a PTLD. Thirty percent of the cytology specimens (11 of 37) appeared reactive, but they lacked sufficient ancillary studies to exclude a PTLD.

CONCLUSIONS

Atypical lymphoid proliferations are common in exfoliative cytology specimens from patients with PTLDs, and they require ancillary studies at least including immunophenotyping and EBV evaluations for a definitive diagnosis. Cancer Cytopathol 2016;124:425-35. © 2016 American Cancer Society.

Post-transplant lymphoproliferative disorders are not associated with IgG4 sclerosing disease

BACKGROUND

Although the majority of post-transplant lymphoproliferative disorder (PTLD) cases are associated with Epstein-Barr virus (EBV), 20-42% of cases are EBV negative (EBV-N). The antigenic stimulus that drives EBV-N PTLD is unknown, but is likely heterogeneous. A common feature of PTLD, regardless of EBV status, is an abnormal polytypic lymphoplasmacytic infiltrate. Immunglobulin-G4 (IgG4) syndrome is also characterized by a polytypic lymphoplasmacytic infiltrate with a predominance of IgG4-positive (IgG4-P) plasma cells.

METHODS

We investigated the possibility of an association between EBV-N PTLD and IgG4 syndrome. Of 33 evaluated PTLD cases, 9 (27%) were EBV-N. EBV-N PTLD cases showed longer transplantation-to-diagnosis times than EBV-positive cases.

RESULTS

A single patient had a preceding benign duodenal biopsy with focally prominent IgG4-P plasma cells; however, no clinical data supported IgG4 syndrome, precluding an association between IgG4 syndrome and subsequent EBV-N PTLD in this patient.

CONCLUSION

As none of 29 evaluable cases of PTLD (including all 9 EBV-N cases) were associated with an increase in IgG4-P plasma cells, IgG4 syndrome does not appear to play a role in the etiology of EBV-N PTLD. The significance of these findings and the current understanding of the etiology of EBV-N PTLD are discussed.

Three different histological subtypes of Epstein-Barr virus-negative post-transplant lymphoproliferative disorder in a patient with hepatitis C infection

We report a rare case in which Epstein-Barr virus (EBV)-negative polymorphic B-cell post-transplant lymphoproliferative disorder (PTLD) and EBV-negative monomorphic T-cell PTLD [anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (ALCL)] were observed simultaneously in the same cervical lymph node, 34 months after liver transplantation for hepatitis C liver cirrhosis. Although hepatitis C recurred after 2 months, he had no other complications until PTLD occurred 34 months post-transplantation. The patient underwent reduction of the immunosuppressive drug and rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone therapy, and he was considered to have achieved complete remission. However, PTLD recurred, and he died 6 months after the initial diagnosis. Autopsy revealed only EBV-negative monomorphic T-cell PTLD (ALK-negative ALCL) that involved the liver, spleen, bilateral kidneys, stomach, bladder, heart, bone marrow, right ureter, and pons. Thus, recurrent PTLD may show a different histological type from the primary disorder, as PTLD has a multiclonal potentiality that causes various types of lymphomas. Therefore, it may be difficult to predict PTLD-related prognosis from the initial PTLD histological identification.

Downregulation of IRF4 induces lytic reactivation of KSHV in primary effusion lymphoma cells

Primary effusion lymphoma (PEL), associated with the latent infection by KSHV, constitutively expresses interferon-regulatory factor 4 (IRF4). We recently showed that IRF4 differentially regulates expression of cellular interferon-stimulated genes (ISGs) and viral genes (Forero et al., 2013). Here, using inducible IRF4 knockdown, we demonstrate that IRF4 silencing results in enhanced transcription of KSHV replication transactivator RTA. As a result viral transcription is increased leading to virus reactivation. Taken together, our results show that IRF4 helps maintain the balance between latency and KSHV reactivation in PEL cells.

A Unique Case of Malignant Pleuropericardial Effusion: HHV-8-Unrelated PEL-Like Lymphoma-A Case Report and Review of the Literature

Primary effusion lymphoma (PEL) or body cavity lymphoma is a rare type of extra nodal lymphoma of B-cell origin that presents as lymphomatous effusion(s) without any nodal enlargement or tumor masses. It belongs to the group of AIDS related non-Hodgkin's lymphomas. First described in 1996 in HIV infected individuals who were coinfected with Kaposi's sarcoma-associated herpesvirus (KSHV) or HHV-8 virus, it was included as a separate entity in WHO classification of tumors of hematopoietic and lymphoid tissue in the year 2001. The definition included association with HHV-8 virus as a mandatory diagnostic criterion. However, cases were later reported where PEL-like disease process was diagnosed in HHV-8 negative patients. This was eventually recognized as a rare but distinct entity termed as “HHV-8-unrelated PEL-like lymphoma”. Herein, we are reporting a case of an elderly patient who presented with a large pleuropericardial effusion and was eventually diagnosed with this entity. Till date, only around 50 cases of HHV-8-unrelated PEL-like lymphoma have been reported and our case being EBV, HIV, and Hepatitis C negative makes it very unique and rare occurrence. We are also presenting a review of relevant literature focused mainly on comparing outcomes in patients treated with and without chemotherapy.

Role of IRF4 in IFN-stimulated gene induction and maintenance of Kaposi sarcoma-associated herpesvirus latency in primary effusion lymphoma cells

IFN regulatory factor (IRF) 4 is a hematopoietic cell-specific transcription factor that regulates the maturation and differentiation of immune cells. Using an inducible expression system, we found that IRF4 directly induced a specific subset of IFN-stimulated genes (ISGs) in a type I IFN-independent manner in both epithelial and B cell lines. Moreover, Kaposi sarcoma-associated herpesvirus (KSHV)-encoded viral FLICE inhibitory protein (vFLIP) enhances IRF4-mediated gene induction. Coexpression of IRF4 with vFLIP significantly increased ISG60 (IFIT3) and Cig5 (RSAD2) transcription that was dependent on the ability of vFLIP to activate NF-κB. A vFLIP mutant (A57L) defective in NF-κB activation failed to enhance IRF4-mediated ISG induction. Thus, we provide a physiologically relevant mechanism by which viral protein-mediated NF-κB activation modulates specific ISG induction by IRF4. In contrast, IRF4 also acted as a negative regulator of KSHV replication and transcription activator expression after induction of KSHV lytic reactivation in KSHV-positive primary effusion lymphoma cells. Taken together, these results suggest a dual role for IRF4 in regulating ISG induction and KSHV lytic reactivation in primary effusion lymphoma cells.

Lymphoid Proliferations Associated With Human Immunodeficiency Virus Infection

Context.—Individuals who are immune deficient are at an increased risk for developing lymphoproliferative lesions and lymphomas. Human immunodeficiency virus (HIV) infection is 1 of 4 clinical settings associated with immunodeficiency recognized by the World Health Organization (WHO) in which there is an increased incidence of lymphoma and other lymphoproliferative disorders.

Objectives.—To describe the major categories of benign lymphoid proliferations, including progressive HIV-related lymphadenopathy, benign lymphoepithelial cystic lesions, and multicentric Castleman disease, as well as the different types of HIV-related lymphomas as defined by the WHO. The characteristic morphologic, immunophenotypic, and genetic features of the different entities will be discussed in addition to some of the pathogenetic mechanisms.

Data Sources.—The WHO classification of tumors of hematopoietic and lymphoid tissues (2001 and 2008), published literature from PubMed (National Library of Medicine), published textbooks, and primary material from the authors' current and previous institutions.

Conclusions.—HIV infection represents one of the clinical settings recognized by the WHO in which immunodeficiency-related lymphoproliferative disorders may arise. Although most lymphomas that arise in patients with HIV infection are diffuse, aggressive B-cell lesions, other lesions, which are “benign” lymphoid proliferations, may also be associated with significant clinical consequences. These lymphoproliferations, like many other immunodeficiency-associated lymphoproliferative disorders, are often difficult to classify. Studies of HIV-associated lymphoid proliferations will continue to increase our understanding of both the immune system and lymphomagenesis.

Human herpesviruses 6, 7 and 8 in solid organ transplant recipients

Human herpesviruses (HHV) 6 and 7 are ubiquitous infections that reactivate commonly in transplant recipients. However, clinical diseases due to these viruses are reported only in 1% of solid organ transplant recipients. Fever, rash and bone marrow suppression are the most common manifestations, but symptoms of tissue invasive disease may be observed. Treatment of HHV-6 and HHV-7 disease includes antiviral therapy and cautious reduction in immunosuppression. HHV-8 is an oncogenic gamma-herpesvirus that causes Kaposi's sarcoma, Castleman's disease and primary effusion lymphomas in transplant recipients. Nonmalignant diseases such as bone marrow suppression and multiorgan failure have also been associated with HHV-8. Reduction in immunosuppression is the first line treatment of HHV-8 infection. Other alternatives for treatment, especially for HHV-8 diseases not responsive to immuno-minimization strategies, are surgery and chemotherapy. Sirolimus has been shown to be a beneficial component for the treatment of Kaposi's sarcoma and the role of antivirals for HHV-8 infection is being investigated.

The radiological spectrum of pulmonary lymphoproliferative disease

Pulmonary lymphoproliferative disorders (LPD) are characterised by abnormal proliferation of indigenous cell lines or infiltration of lung parenchyma by lymphoid cells. They encompass a wide spectrum of focal or diffuse abnormalities, which may be classified as reactive or neoplastic on the basis of cellular morphology and clonality. The spectrum of reactive disorders results primarily from antigenic stimulation of bronchial mucosa-associated lymphoid tissue (MALT) and comprises three main entities: follicular bronchiolitis, lymphoid interstitial pneumonia and (more rarely) nodular lymphoid hyperplasia. Primary parenchymal neoplasms are most commonly extranodal marginal zone lymphomas of MALT origin (MALT lymphomas), followed by diffuse large B-cell lymphomas (DLBCLs) and lymphomatoid granulomatosis (LYG). Secondary lymphomatous parenchymal neoplasms (both Hodgkin and non-Hodgkin lymphomas) are far more prevalent than primary neoplasms. Acquired immune deficiency syndrome (AIDS)-related lymphoma (ARL) and post-transplantation lymphoproliferative disorder (PTLD) may also primarily affect the lung parenchyma. Modern advances in treatments for AIDS and transplant medicine are associated with an increase in the incidence of LPD and have heightened the need to understand the range of imaging appearance of these diseases. The multidetector CT (MDCT) findings of LPD are heterogeneous, thereby reflecting the wide spectrum of clinical manifestations of these entities. Understanding the spectrum of LPD and the various imaging manifestations is crucial because the radiologist is often the first one to suggest the diagnosis and has a pivotal role in differentiating these diseases. The current concepts of LPD are discussed together with a demonstration of the breadth of MDCT patterns within this disease spectrum.

How I treat HHV8/KSHV-related diseases in posttransplant patients

Posttransplantation human herpesvirus-8 (HHV8)/Kaposi sarcoma herpesvirus (KSHV) primary infection and/or reactivations are associated with uncommon and sometimes fatal, neoplastic, and non-neoplastic diseases. HHV8-related clinical manifestations notably range from Kaposi sarcoma (KS) to either primary effusion lymphoma or multicentric Castleman disease B-cell malignancies, and from polyclonal HHV8-positive plasmacytic lymphoproliferative disorders to bone marrow failure and peripheral cytopenias, associated or not with hemophagocytic syndromes, and to acute hepatitis syndromes. We reviewed the patient series reported in the literature and summarized clinical management aspects, in terms of diagnosis, follow-up, and treatment. We described typical clinical presentations and histopathologic diagnostic features of these diseases, and we discussed the role of HHV8-specific serologic, molecular, and immunologic assays, particularly focusing on recent data from HHV8-specific T-cell monitoring in posttransplantation KS patients. We finally discussed actual therapeutic options, namely, the reduction or discontinuation of immunosuppressive therapy or the switch from calcineurin inhibitors to mTOR inhibitors, as alternatives to antineoplastic chemotherapy, along with the use of antiherpesvirus agents as prophylactic or therapeutic measures, and treatment with rituximab in posttrans-plantation multicentric Castleman disease patients and non-neoplastic HHV8-associated syndromes.

An unusual case of Primary Effusion Lymphoma with aberrant T-cell phenotype in a HIV-negative, HBV-positive, cirrhotic patient, and review of the literature

Primary effusion lymphoma (PEL) is an unusual, human herpes virus-8 (HHV-8)-associated type of lymphoma, presenting as lymphomatous effusion in body cavities, without a detectable tumor mass. It primarily affects human immunodeficiency virus (HIV)-infected patients, but has also been described in other immunocompromised individuals. Although PEL is a B-cell lymphoma, the neoplastic cells are usually of the 'null' phenotype by immunocytochemistry. This report describes a case of PEL with T-cell phenotype in a HIV-negative patient and reviews all the relevant cases published until now. Our patient suffered from cirrhosis associated with Hepatitis B virus (HBV) infection and presented with a large ascitic effusion, in the absence of peripheral lymphadenopathy or solid mass within either the abdomen or the thorax. Paracentesis disclosed large lymphoma cells with anaplastic features consisting of moderate cytoplasm and single or occasionally multiple irregular nuclei with single or multiple prominent nucleoli. Immunocytochemically, these cells were negative for both CD3 and CD20, but showed a positive reaction for T-cell markers CD43 and CD45RO (VCHL-1). Furthermore, the neoplastic cells revealed strong positivity for EMA and CD30, but they lacked expression of ALK-1, TIA-1, and Perforin. The immune status for both HHV-8 and Epstein-Barr virus (EBV) was evaluated and showed positive immunostaining only for the former. The combination of the immunohistochemistry results with the existence of a clonal rearrangement in the immunoglobulin heavy chain gene (identified by PCR), were compatible with the diagnosis of PEL. The presence of T-cell markers was consistent with the diagnosis of PEL with an aberrant T-cell phenotype.

Primary effusion lymphoma with central nervous system involvement in an HIV-negative homosexual male

Primary effusion lymphoma (PEL) is a rare form of non-Hodgkin lymphoma that presents with body cavity effusions. It occurs chiefly in immunodeficient HIV-positive patients. The tumor cells generally express gene sequences of human herpesvirus-8 (HHV-8) and Epstein-Barr virus (EBV). Tumor cells of HIV-negative patients usually express HHV-8 gene sequences, but rarely those of EBV. We report a novel case of PEL in an HIV-negative homosexual male whose tumor cells expressed both HHV-8 and EBV gene sequences and who developed evidence of central nervous system involvement.

β-HHVs and HHV-8 in Lymphoproliferative Disorders

Similarly to Epstein-Barr virus (EBV), the human herpesvirus-8 (HHV-8) is a γ-herpesvirus, recently recognized to be associated with the occurrence of rare B cell lymphomas and atypical lymphoproliferations, especially in the human immunodeficiency virus (HIV) infected subjects. Moreover, the human herpesvirus-6 (HHV-6), a β-herpesvirus, has been shown to be implicated in some non-malignant lymph node proliferations, such as the Rosai Dorfman disease, and in a proportion of Hodgkin’s lymphoma cases. HHV-6 has a wide cellular tropism and it might play a role in the pathogenesis of a wide variety of human diseases, but given its ubiquity, disease associations are difficult to prove and its role in hematological malignancies is still controversial. The involvement of another β-herpesvirus, the human cytomegalovirus (HCMV), has not yet been proven in human cancer, even though recent findings have suggested its potential role in the development of CD4⁺ large granular lymphocyte (LGL) lymphocytosis. Here, we review the current knowledge on the pathogenetic role of HHV-8 and human β-herpesviruses in human lymphoproliferative disorders.

Phosphatase and tensin homolog on chromosome 10 is phosphorylated in primary effusion lymphoma and Kaposi's sarcoma

Primary effusion lymphoma (PEL) is a non-Hodgkin's B-cell lymphoma driven by Kaposi's sarcoma-associated herpesvirus. It is uniquely sensitive to mTOR, PI3K, and Akt inhibitors; however, the basis of this requirement for the mTOR pathway remains to be elucidated. The phosphatase and tensin homolog gene (PTEN) on chromosome 10 controls the first step in the phosphatidylinositol 3 kinase (PI3K)-Akt-mammalian target of rapamycin (mTOR) pathway and is genetically inactivated in many solid tumors. We find an absence of PTEN deletions, mutations, or protein mislocalization in PEL. However, we find consistent hyperphosphorylation at serine 380 of PTEN, which is an inactivating modification, in PEL cell lines and in tumor xenografts. We also evaluated a large tissue microarray of Kaposi's sarcoma biopsies and observed concordant high levels of phospho-PTEN, phospho-Akt, and phospho-S6 ribosomal protein. Reintroduction of PTEN into PEL inhibited colony formation in soft agar, verifying the functional dependence of PEL on PI3K signaling. This was also true for PEL cell lines that carried mutant p53 and for KS-like cell lines. Activating PTEN in these cancers may yield a new treatment strategy for PEL, KS, and similar PTEN wild-type lymphomas.

Herpes viruses in transplant recipients: HSV, VZV, human herpes viruses, and EBV

The herpes viruses are responsible for a wide range of diseases in patients following transplant, resulting from direct viral effects and indirect effects, including tumor promotion. Effective treatments and prophylaxis exist for the neurotropic herpes viruses HSV-1, HSV-2, varicella zoster virus, and possibly HHV-6. Antivirals seem to be less effective at prevention of the tumor-promoting effects of Epstein-Barr virus and HHV-8. Reduction in immunosuppression is the cornerstone to treatment of many diseases associated with herpes virus infections.

[Primary effusion lymphoma in two kidney transplant recipients]

BACKGROUND

Primary effusion lymphoma (PEL) is a highly malignant non-Hodgkin lymphoma associated with Kaposi's sarcoma-associated herpesvirus/human herpesvirus-8 infection (KSHV/HHV-8). It is chiefly seen in HIV patients and is rare in transplant recipients, possibly going unrecognized.

OBSERVATION

We describe two male kidney transplant recipients, aged 47 and 51 years, followed for Kaposi's sarcoma in skin, lymph nodes, gastrointestinal (GI) tract and lung whose disease was poorly controlled by sirolimus and chemotherapy. Recurrent pleural effusion contrasted with reduction of cutaneous Kaposi lesions. KHSV viral loads were negative or very low in plasma, were negative or very low, whereas those in pleural effusion were high. Lymphoma cells were discovered only seven to nine months after the initial effusion despite repeated needle biopsies. In one patient, tumour cells were co-infected with Epstein-Barr virus.

CONCLUSION

The contrast between a very low KHSV viral load in plasma and a very high viral load pleural effusion should alert physicians and prompt suspicion of PEL in Kaposi's sarcoma patients with recurrent serous effusion. The potential inhibitory role of sirolimus on PEL progression is discussed.

Imaging of posttransplantation lymphoproliferative disorder after solid organ transplantation

Posttransplantation lymphoproliferative disorders (PTLDs) are a heterogeneous group of diseases that represent uncommon complications of transplantation and can lead to significant morbidity and mortality. PTLD is most prevalent during the first year following transplantation and occurs most frequently in multiorgan transplant recipients, followed by bowel, heart-lung, and lung recipients. It may involve any of the organ systems, with disease manifestation and the anatomic pattern of organ involvement being highly dependent on the type of transplantation. The current classification system includes four subtypes that have different prognoses requiring different treatment strategies. Tissue sampling is necessary for diagnosis and further subcategorization. The majority of cases are characterized by B-cell proliferation and are related to infection from Epstein-Barr virus. Knowledge of the distribution and radiologic features of PTLD allows the radiologist to play a pivotal role in making an early diagnosis and in guiding biopsy.

Primary Cardiac Lymphoma: Report of Two Cases Occurring in Immunocompetent Subjects

Primary cardiac lymphomas (PCLs), involving solely heart and/or pericardium at presentation, are rare events. They are frequently recognized at autopsy and generally carry a poor prognosis due either to a delay in the diagnosis or to infiltration of heart structures. We report here on two patients with large B-cell PCL. One is a 52-year-old man who presented with multiple cardiac tumors infiltrating mainly the right atrium and the inter-atrial septum. Diagnosis was established by ultrasound-assisted transesophageal biopsy of the intra-atrial multilobated tumor mass. He was treated with Rituximab-implemented high-dose sequential (R-HDS) chemotherapy followed by autologous peripheral blood stem cell transplantation, attaining complete response. He had no evidence of disease 24 months from onset. The second patient was a 70-year-old woman who presented with pericardial tamponade and low-output cardiac failure. Despite prompt pericadiocentesis and chemotherapy with cyclophosphamide and vincristine, she died 2 weeks later. Postmortem examination revealed large B-cell lymphoma proliferation confined to the heart. Whether primitive heart localizations represent an independent prognostic factor, and what specific measures should be adopted in patients with this rare presentation is the subject of the present report and review of the literature.

Diffuse Large B-Cell Lymphoma—More Than a Diffuse Collection of Large B Cells: An Entity in Search of a Meaningful Classification

Context.—Diffuse large B-cell lymphoma is a heterogenous group of lymphomas. In this review, we present a brief description of the large number of entities recognized in the recently published (2008) World Health Organization classification of tumors of hematopoietic and lymphoid tissues.

Objective.—We highlight the unique clinicopathologic and molecular genetic features of these new and previously recognized entities, to illustrate the rational for the development of this classification. To help simplify the understanding of this now large and complex group of diseases, we have attempted to create broader subgroups of related entities. We discuss large B-cell lymphoma that are not otherwise specified, those that are based on anatomic site, those that have unique histology or phenotype or genotype, those that are associated with Epstein-Barr virus or Kaposi sarcoma–associated herpesvirus and herpesvirus 8, and those that are unclassifiable.

Data Sources.—World Health Organization classification of tumors of hematopoietic and lymphoid tissues (2008), published literature from PubMed (National Library of Medicine), and primary material from the authors' institution were reviewed.

Conclusions.—Recognition of the different subtypes of diffuse large B-cell lymphoma as described in the World Health Organization classification scheme will lead to improved understanding of the unique clinicopathologic and genetic features associated with these subtypes of lymphoma.

Primary effusion lymphoma diagnosed by pericardiocentesis

Primary effusion lymphoma (PEL), formerly known as body cavity-based lymphoma, is a high-grade B-cell non-Hodgkin's lymphoma associated with Kaposi's sarcoma and human herpesvirus 8 infection. It usually affects serous body cavities and results in recurrent lymphomatous effusions. PEL is often diagnosed in patients with HIV infection and carries a poor prognosis, with median survival near 6 months. We describe a patient who presented with symptomatic pericardial effusion, secondary to newly diagnosed PEL, and no prior history of HIV infection.

HIV-associated lymphomas and gamma-herpesviruses

Among the most common HIV-associated lymphomas are Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL) with immunoblastic-plasmacytoid differentiation (also involving the central nervous system). Lymphomas occurring specifically in HIV-positive patients include primary effusion lymphoma (PEL) and its solid variants, plasmablastic lymphoma of the oral cavity type and large B-cell lymphoma arising in Kaposi sarcoma herpesvirus (KSHV)-associated multicentric Castleman disease. These lymphomas together with BL and DLBCL with immunoblastic-plasmacytoid differentiation frequently carry EBV infection and display a phenotype related to plasma cells. EBV infection occurs at different rates in different lymphoma types, whereas KSHV is specifically associated with PEL, which usually occurs in the setting of profound immunosuppression. The current knowledge about HIV-associated lymphomas can be summarized in the following key points: (1) lymphomas specifically occurring in patients with HIV infection are closely linked to other viral diseases; (2) AIDS lymphomas fall in a spectrum of B-cell differentiation where those associated with EBV or KSHV commonly exhibit plasmablastic differentiation; and (3) prognosis for patients with lymphomas and concomitant HIV infection could be improved using better combined chemotherapy protocols incorporating anticancer treatments and antiretroviral drugs.