Human herpesvirus 8 (HHV-8)-associated peritoneal primary effusion lymphoma (PEL) in two HIV-negative elderly patients

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.

Serous fluids and hematolymphoid disorders

Diagnosing hematolymphoid neoplasm by evaluating fine-needle aspiration (FNA) cytology sample is controversial and requires experience and clinical skills. This concept becomes more challenging when evaluating hematolymphoid neoplasm in body fluid. Differentiating between low-grade lymphoma and reactive lymphocytes is often difficult by morphology alone as reactive lymphoid cells may acquire activation morphology from being exposed to different cytokines within the body fluid. However, in most cases there are specific features that may aid in differentiating small reactive from non-reactive lymphocytes including the round shape of the nucleus, the absence of visible nucleoli and the presence of fine clumped chromatin. In large cell lymphoma and leukemia cells involvement of body fluid this concept becomes less challenging. Large cell lymphoma and leukemia cells tend to have large size nuclei, less mature chromatin, and visible nucleoli with and without cytoplasmic vacuoles. However, to reach accurate diagnosis and subclassification, the utilizing of flow cytometry, to confirm monoclonality, and other ancillary studies such immunocytochemistry, cytogenetics and molecular studies is needed. This review article will be incorporated finally as one of the chapters in CMAS (CytoJournal Monograph/Atlas Series) #2. It is modified slightly from the chapter by the initial authors in the first edition of Diagnostic Cytopathology of Serous Fluids.

Primary human herpesvirus 8-negative effusion-based lymphoma: a large B-cell lymphoma with favorable prognosis

Primary effusion-based lymphoma (EBL) presents as a malignant effusion in a body cavity. The clinicopathologic features and prognosis of primary human herpesvirus 8 (HHV8)-negative EBL remain unclear. We therefore conducted a retrospective study of 95 patients with EBL, regardless of HHV8 status, in Japan. Of 69 patients with EBL tested for HHV8, a total of 64 were negative. The median age of patients with primary HHV8-negative EBL at diagnosis was 77 years (range, 57-98 years); all 58 tested patients were negative for HIV. Primary HHV8-negative EBL was most commonly diagnosed in pleural effusion (77%). Expression of at least 1 pan B-cell antigen (CD19, CD20, or CD79a) was observed in all cases. According to the Hans algorithm, 30 of the 38 evaluated patients had nongerminal center B-cell (non-GCB) tumors. Epstein-Barr virus-encoded small RNA was positive in 6 of 45 patients. In 56 of 64 HHV8-negative patients, systemic therapy was initiated within 3 months after diagnosis. Cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP) or CHOP-like regimens with or without rituximab (n = 48) were the most common primary treatments. The overall response and complete response rates were 95% and 73%, respectively. Three patients did not progress without systemic treatment for a median of 24 months. With a median 25-month follow-up, the 2-year overall survival and progression-free survival rates were 84.7% and 73.8%. Sixteen patients died; 12 were lymphoma-related deaths. Thus, most EBL cases in Japan are HHV8-negative and affect elderly patients. The non-GCB subtype is predominant. Overall, primary HHV8-negative EBL exhibits a favorable prognosis after anthracycline-based chemotherapy.

Lenalidomide in Combination with Arsenic Trioxide: an Effective Therapy for Primary Effusion Lymphoma

Primary effusion lymphoma (PEL) is a rare aggressive subset of non-Hodgkin B cell lymphoma. PEL is secondary to Kaposi sarcoma herpes virus (KSHV) and predominantly develops in serous cavities. Conventional chemotherapy remains the treatment of choice for PEL and yields high response rates with no significant comorbidities. Yet, chemotherapy often fails in achieving or maintaining long-term remission. Lenalidomide (Lena), an immunomodulatory drug, displayed some efficacy in the treatment of PEL. On the other hand, arsenic trioxide (ATO) in combination with other agents effectively treated a number of blood malignancies, including PEL. In this study, we present evidence that the combination of ATO/Lena significantly enhanced survival of PEL mice, decreased the volume of exacerbated ascites in the peritoneum, and reduced tumor infiltration in organs of treated animals. In ex vivo treated PEL cells, ATO/Lena decreased the proliferation and downregulated the expression of KSHV latent viral proteins. This was associated with decreased NF-κB activation, resulting in reactivation of viral replication, downregulation of interleukin-6 (IL-6) and IL-10, inhibition of vascular endothelial growth factor, and apoptosis. Our results elucidate the mechanism of action of ATO/Lena and present it as a promising targeted therapeutic modality in PEL management, which warrants further clinical investigation.

PCR Detection of HHV8 DNA in the Saliva of Removable Denture Wearers Compared to Dentate Cases in Shiraz, South of Iran

Result

In the denture wearers, HHV8 DNA was detected in 11 cases. Two of the controls amplified HHV8 DNA. Fisher's exact test demonstrates a significant difference between virus infection and using removable dentures (p = 0.015).

Conclusion

Our findings suggested that HHV8 detection could be associated with use of denture.

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.

Retinoids as an Immunity-modulator in Dermatology Disorders

The skin is the largest epithelial surface protecting the body from invading microbes. Vitamin A plays vital roles in the host defence of the skin, including promoting epithelial cell integrity, proliferation, and differentiation and even mediating immune responses. Furthermore, vitamin A derivatives, retinoid drugs, are widely used to treat skin diseases, such as acne and psoriasis. However, the immunoregulatory mechanisms of retinoids in dermatology have not been systematically described. In this paper, we discuss the immunological functions of retinoids during disease treatment, especially in skin disorders caused by exogenous infections.

Primary effusion lymphoma in a human immunodeficiency virus-negative patient with unexpected unusual complications: a case report

BACKGROUND

Primary effusion lymphoma is a rare, high-grade non-Hodgkin's lymphoma that usually occurs in immunosuppressed or human immunodeficiency virus-positive individuals in advanced stages of the disease. However, primary effusion lymphoma occasionally affects immunocompetent patients who are infected with human herpes virus type 8 or Epstein-Barr virus. This disease manifests with liquid collections in cavities, producing constitutional symptoms; fever; weight loss; and symptoms related to extrinsic compression, such as dyspnea or abdominal discomfort. Diagnosis is confirmed with cytological or tissue evaluation showing large, multinucleated lymphoid cells with positive specific markers for the disease, such as CD45 and markers related to viral infections, when present. There is no standard treatment for primary effusion lymphoma, but several chemotherapy protocols are recommended, usually with poor results.

CASE PRESENTATION

We present a case of an adult human immunodeficiency virus-negative Hispanic origin woman with primary effusion lymphoma with pleuritic, pericardial, and peritoneal compromise who also had unusual complications during a diagnostic procedure: the accidental rupture of the left ventricle and the development of a secondary left ventricular pseudoaneurysm. We describe the clinical, radiological, and laboratory characteristics as well as the outcome of this case.

CONCLUSIONS

Primary effusion lymphoma is a very rare entity that represents 4% of non-Hodgkin's lymphoma cases associated with human immunodeficiency virus and 0.1% to 1% of all lymphomas in patients with another type of immunodeficiency in regions where human herpes virus type 8 is not endemic. This reported case is an unusual presentation of primary effusion lymphoma because it occurred in an immunocompetent human immunodeficiency virus-negative adult woman without the presence of Kaposi's sarcoma or Castleman's disease and for whom the clinical course after chemotherapy was successful. However, the rupture of the free wall of the left ventricle is a very rare catastrophic event that usually occurs after myocardial infarction. Left ventricle free wall rupture rarely goes unnoticed, but when it occurs, it leads to the development of a ventricular pseudoaneurysm in which the rupture is contained by the pericardium with an organized thrombus and an adjacent hematoma.

Human Herpesvirus 8 and Lymphoproliferative Disorders

The spectrum of lymphoproliferative disorders linked to human herpesvirus 8 (HHV-8) infection has constantly been increasing since the discovery of its first etiologic association with primary effusion lymphoma (PEL). PEL is a rapidly progressing non-Hodgkin’s B-cell lymphoma that develops in body cavities in an effusional form. With the increase in the overall survival of PEL patients, as well as the introduction of HHV-8 surveillance in immunocompromised patients, the extracavitary, solid counterpart of PEL was later identified. Moreover, virtually all plasmablastic variants of multicentric Castleman’s disease (MCD) developing in HIV-1-infected individuals harbor HHV-8, providing a strong etiologic link between MCD and this oncogenic herpesvirus. Two other pathologic conditions develop in HIV-1-infected persons concomitantly with MCD: MCD with plasmablastic clusters and HHV-8-positive diffuse large B-cell lymphoma not otherwise specified (HHV-8+ DLBCL NOS), the first likely representing an intermediate stage preceding the full neoplastic form. MCD in leukemic phase has also been described, albeit much less commonly. The germinotropic lymphoproliferative disorder (GLPD) may resemble extracavitary PEL, but develops in immune competent HHV8-infected individuals, and, unlike the other disorders, it responds well to conventional therapies. Almost all HHV-8-mediated lymphoproliferative disorders are the result of an interaction between HHV-8 infection and a dysregulated immunological system, leading to the formation of inflammatory niches in which B cells, at different developmental stages, are infected, proliferate and may eventually shift from a polyclonal state to a monoclonal/neoplastic disorder. Herein, we describe the association between HHV-8 and lymphoproliferative disorders and highlight the predominant distinctive features of each disease.

Primary effusion lymphoma: current perspectives

Primary effusion lymphoma (PEL) is a rare and aggressive disease, affecting a unique population of patients who are often elderly or immunocompromised. PEL is associated with human herpesvirus type-8 infection and most commonly presents as malignant effusions of the body cavities. Patients diagnosed with PEL often have a compromised immune system from secondary conditions such as HIV. Chemotherapy has traditionally been the cornerstone of treatment for patients with a good performance status and no significant comorbidities. However, an optimal regimen does not exist. Most patients with PEL experience a relapse after frontline therapy within 6-8 months and subsequently require further treatment. In recent years, our understanding of the molecular drivers and environmental factors affecting the pathogenesis of PEL has expanded. This review will discuss the pathogenesis of PEL and various management approaches available in the frontline and relapsed setting as well as targeted agents that have shown promise in this disease.

HHV8/KSHV-Positive Lymphoproliferative Disorders and the Spectrum of Plasmablastic and Plasma Cell Neoplasms: 2015 SH/EAHP Workshop Report-Part 3

OBJECTIVES

The 2015 Workshop of the Society for Hematopathology/European Association for Haematopathology aimed to review immunodeficiency-related lymphoproliferative disorders with plasmablastic and plasma cell differentiation.

METHODS

The workshop panel reviewed human herpes virus 8 (HHV8)/Kaposi sarcoma herpesvirus (KSHV)-associated lesions and other lesions exhibiting plasma cell differentiation, including plasmablastic proliferations with features of myeloma/plasmacytoma, plasmablastic neoplasms presenting in extranodal sites and effusion-based lymphomas, and rendered a consensus diagnosis.

RESULTS

The spectrum of HHV8/KSHV-associated proliferations ranged from multicentric Castleman disease (MCD) to MCD with plasmablastic aggregates to HHV8+ diffuse large B-cell lymphoma and germinotrophic lymphoproliferative disorder. Comparisons across effusion-based lymphomas with and without HHV8/KSHV and plasmablastic lymphomas in immunodeficient and immunocompetent patients were discussed.

CONCLUSIONS

The presence or absence of HHV8/KSHV is a defining feature in disorders associated with Castleman disease, although their differential diagnosis and recognition of progression may be challenging. Plasmablastic proliferations overlap with myeloma/plasmacytoma as well as extranodal and effusion-based lymphomas. The involvement of Epstein-Barr virus is typically variable.

Cutaneous EBV-related lymphoproliferative disorders

This article will focus on the cutaneous lymphoproliferative disorders associated with EBV, with an emphasis on the upcoming changes in the revised 4th Edition of the WHO classification of tumors of the hematopoietic system, many of which deal with cutaneous disorders derived from NK-cells or T-cells. Extranodal NK/T-cell lymphoma usually presents in the upper aerodigestive tract, but can involve the skin secondarily. EBV-associated T- and NK-cell lymphoproliferative disorders (LPD) in the pediatric age group include the systemic diseases, chronic active EBV infection (CAEBV) and systemic EBV+ T-cell lymphoma of childhood. Hydroa vacciniforme (HV)-like LPD is a primarily cutaneous form of CAEBV and encompasses the lesions previously referred to as HV and HV-like lymphoma (HVLL). All the T/NK-cell-EBV-associated diseases occur with higher frequency in Asians, and indigenous populations from Central and South America and Mexico. Among the B-cell EBV-associated LPD two major changes have been introduced in the WHO. The previously designated EBV-positive diffuse large B-cell lymphoma (EBV-DLBCL) of the elderly, has been changed to EBV-DLBCL with 'not otherwise specified' as a modifier (NOS). A new addition to the WHO system is the more recently identified EBV+ mucocutaneous ulcer, which involves skin and mucosal-associated sites.

Primary effusion lymphoma presenting as a cutaneous intravascular lymphoma

Primary effusion lymphoma (PEL) is a rare and aggressive lymphoma that arises in the context of immunosuppression and is characterized by co-infection with Epstein-Barr virus (EBV) and human herpesvirus-8/Kaposi sarcoma-associated herpesvirus (HHV-8/KSHV). It was originally described as arising in body cavity effusions, but presentation as a mass lesion (extracavitary PEL) is now recognized. Here, we describe a case of PEL with an initial presentation as an intravascular lymphoma with associated skin lesions. The patient was a 53-year-old man with human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) who presented with fevers, weight loss and skin lesions concerning for Kaposi sarcoma (KS). A skin biopsy revealed no evidence of KS; however, dermal vessels contained large atypical cells that expressed CD31 and plasma cell markers but lacked most B- and T-cell antigens. The atypical cells expressed EBV and HHV-8. The patient subsequently developed a malignant pleural effusion containing the same neoplastic cell population. The findings in this case highlight the potential for unusual intravascular presentations of PEL in the skin as well as the importance of pursuing microscopic diagnosis of skin lesions in immunosuppressed patients.

Targeting Myc in KSHV-associated primary effusion lymphoma with BET bromodomain inhibitors

Primary effusion lymphoma (PEL) is an aggressive form of non-Hodgkin's B-cell lymphoma associated with infection by Kaposi's sarcoma-associated herpes virus (KSHV). (+)-JQ1 and I-BET151 are two recently described novel small-molecule inhibitors of BET bromodomain chromatin-associated proteins that have shown impressive preclinical activity in cancers in which MYC is overexpressed at the transcriptional level due to chromosomal translocations that bring the MYC gene under the control of a super-enhancer. PEL cells, in contrast, lack structural alterations in the MYC gene, but have deregulated Myc protein due to the activity of KSHV-encoded latent proteins. We report that PEL cell lines are highly sensitive to bromodomain and extra-terminal (BET) bromodomain inhibitors-induced growth inhibition and undergo G0/G1 cell-cycle arrest, apoptosis and cellular senescence, but without the induction of lytic reactivation, upon treatment with these drugs. Treatment of PEL cell lines with BET inhibitors suppressed the expression of MYC and resulted in a genome-wide perturbation of MYC-dependent genes. Silencing of BRD4 and MYC expression blocked cell proliferation and cell-cycle progression, while ectopic expression of MYC from a retroviral promoter rescued cells from (+)-JQ1-induced growth arrest. In a xenograft model of PEL, (+)-JQ1 significantly reduced tumor growth and improved survival. Taken collectively, our results demonstrate that the utility of BET inhibitors may not be limited to cancers in which genomic alterations result in extremely high expression of MYC and they may have equal or perhaps greater activity against cancers in which the MYC genomic locus is structurally intact and c-Myc protein is deregulated at the post-translational level and is only modestly overexpressed.

HHV-8-positive and EBV-positive intravascular lymphoma: an unusual presentation of extracavitary primary effusion lymphoma

Intravascular lymphomas are rare and aggressive hematolymphoid tumors. Here, we describe a human herpesvirus type-8 (HHV-8)/Kaposi sarcoma-associated herpesvirus-positive and Epstein-Barr virus (EBV)-positive intravascular lymphoma. The patient was a 59-year-old human immunodeficiency virus-positive man who presented with diarrhea, abdominal pain, fevers, night sweats, and weight loss. Radiographic studies of the abdomen and pelvis revealed numerous subcentimeter nodules within the subcutaneous fat that lacked connection to the skin. An excisional biopsy demonstrated large atypical cells within vessels in the deep subcutaneous fat, and many of the vessels contained extensive organizing thrombi. The atypical cells lacked strong expression of most B-cell markers but were positive for MUM-1 and showed partial expression of several T-cell markers. An immunohistochemical stain for HHV-8 and an in situ hybridization for EBV were both positive in the neoplastic cells. The disease had a rapidly progressive and fatal course. This lymphoma appears to represent an entirely intravascular form of primary effusion lymphoma and highlights the propensity for HHV-8 and EBV-positive lymphoid neoplasms to show aberrant expression of T-cell markers, illustrates the utility of skin biopsies for the diagnosis of intravascular lymphoma, and suggests that biopsies to evaluate for intravascular lymphoma should be relatively deep and include subcutaneous fat.

Human Immunodeficiency Virus (HIV)-Negative and Human Herpes Virus-8 (HHV-8)-Positive Primary Effusion Lymphoma: A Case Report and Review of the Literature

Primary effusion lymphoma (PEL) is a rare type of non-Hodgkin lymphoma that presents with serosal effusion in body cavities, without obvious tumor masses. Although PEL occurs in immunocompromised patients that are human immunodeficiency virus (HIV) positive, it also occurs in immunocompetent human herpes virus-8 (HHV-8)-positive patients. Herein we present an immunocompetent, HIV-negative, CD-20-negative, HHV-8-positive patient with pleural effusion that was diagnosed as PEL. The CHOP protocol and talc pleurodesis were administered. HHV-8 plays a causative role in PEL and is important for differentiating PEL from other types of lymphoma. As such, in addition to pleurodesis antiviral treatment should be considered for optimal treatment outcome.

Conflict of interest:None declared.

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.

Human herpesvirus-8 infection leads to expansion of the preimmune/natural effector B cell compartment

Background

Human herpesvirus-8 (HHV-8) is the etiological agent of Kaposi's sarcoma (KS) and of some lymphoproliferative disorders of B cells. Most malignancies develop after long-lasting viral dormancy, and a preventing role for both humoral and cellular immune control is suggested by the high frequency of these pathologies in immunosuppressed patients. B cells, macrophages and dendritic cells of peripheral lymphoid organs and blood represent the major reservoir of HHV-8. Due to the dual role of B cells in HHV-8 infection, both as virus reservoir and as agents of humoral immune control, we analyzed the subset distribution and the functional state of peripheral blood B cells in HHV-8-infected individuals with and without cKS.

Methodology/Principal Findings

Circulating B cells and their subsets were analyzed by 6-color flow cytometry in the following groups: 1- patients HHV-8 positive with classic KS (cKS) (n = 47); 2- subjects HHV-8 positive and cKS negative (HSP) (n = 10); 3- healthy controls, HHV-8 negative and cKS negative (HC) (n = 43). The number of B cells belonging to the preimmune/natural effector compartment, including transitional, pre-naïve, naïve and MZ-like subsets, was significantly higher among HHV-8 positive subjects, with or without cKS, while was comparable to healthy controls in the antigen-experienced T-cell dependent compartment. The increased number of preimmune/natural effector B cells was associated with increased resistance to spontaneous apoptosis, while it did not correlate with HHV-8 viral load.

Conclusions/Significance

Our results indicate that long-lasting HHV-8 infection promotes an imbalance in peripheral B cell subsets, perturbing the equilibrium between earlier and later steps of maturation and activation processes. This observation may broaden our understanding of the complex interplay between viral and immune factors leading HHV-8-infected individuals to develop HHV-8-associated malignancies.

Notch1 in primary effusion lymphoma: a clinicopathological study

Primary effusion lymphoma is a human herpes virus 8 (HHV-8)-associated large cell lymphoma of body cavities. Detailed large-scale clinicopathological studies are rarely reported, and the underlying mechanism of lymphomagenesis remains elusive. In the present report, we studied the clinicodemographic, immunophenotypic, and cytomorphological features on a cohort of 12 cases of primary effusion lymphoma. In contrast to HHV-8, which was positive in all nine cases tested (100%), HIV was found in 75% (9/12) of cases, whereas the three HIV-negative cases were either in elderly patients (one with hepatitis C virus infection and one with asbestoses exposure) or in a heart transplantation recipient. By flow cytometry, the antigens expressed in descending order were CD38, CD71, HLA-DR, CD30, and CD45RO. B-cell markers were largely negative. Cytomorphologically, all cases showed atypical to anaplastic morphology. Notch1, a member of transmembrane signal transduction family, was found in six of seven HHV-8-positive cases (86%). In agreement with in vitro studies using human primary effusion lymphoma cell lines, we have found that Notch1 was expressed in the majority of HHV-8-positive primary effusion lymphoma cases, corroborating the notion that Notch1 may have an important role in HHV-8-mediated lymphomagenesis of primary effusion lymphoma.

EBV and HIV-Related Lymphoma

HIV-associated lymphoproliferative disorders represent a heterogeneous group of diseases, arising in the presence of HIV-associated immunodeficiency. The overall prevalence of HIV-associated lymphoma is significantly higher compared to that of the general population and it continues to be relevant even after the wide availability of highly active antiretroviral therapy (HAART) (1). Moreover, they still represent one of the most frequent cause of death in HIV-infected patients. Epstein-Barr virus (EBV), a γ-Herpesviruses, is involved in human lymphomagenesis, particularly in HIV immunocompromised patients. It has been largely implicated in the development of B-cell lymphoproliferative disorders as Burkitt lymphoma (BL), Hodgkin disease (HD), systemic non Hodgkin lymphoma (NHL), primary central nervous system lymphoma (PCNSL), nasopharyngeal carcinoma (NC). Virus-associated lymphomas are becoming of significant concern for the mortality of long-lived HIV immunocompromised patients, and therefore, research of advanced strategies for AIDS-related lymphomas is an important field in cancer chemotherapy. Detailed understanding of the EBV lifecycle and related cancers at the molecular level is required for novel strategies of molecular-targeted cancer chemotherapy The linkage of HIV-related lymphoma with EBV infection of the tumor clone has several pathogenetic, prognostic and possibly therapeutic implications which are reviewed herein.

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.

Vascular changes in merkel cell carcinoma based on a histopathological study of 92 cases

Although prominent vascular proliferation is a known feature of various neuroendocrine tumors, it has not been systematically studied in Merkel cell carcinoma (MCC) of the skin. The purpose of this study was to fully characterize the light microscopic, immunohistochemical, and ultrastructural features of vascular changes associated with MCC and to determine their frequency and differential diagnostic implications. Additionally, the presence of human herpesvirus 8 DNA in the lesional tissue was investigated. Of 92 studied cases of MCC, 18 cases (20%) were found to exhibit foci of prominent vascular changes which were classified into the following 6 patterns: pericyte hyperplasia, pyogenic granuloma-like, hemangioendothelioma-like, epithelioid hemangioma-like, peliosis-like, and follicular dendritic cell tumor-like pattern. In addition, Azzopardi phenomenon was observed. These changes occurred singly or in combination. Human herpesvirus 8 DNA was identified by polymerase chain reaction in none of the 18 cases. It is concluded that prominent vascular proliferations may be seen in 20% of MCC, and thereby, MCC resembles neuroendocrine tumors in other organs. When unduly prominent and encountered in a limited biopsy specimen, vascular alterations may represent a potential diagnostic pitfall, but, on the other hand, they themselves may serve as a clue to the correct diagnosis. Human herpesvirus 8 does not play a role in angiogenesis in MCC.

HIV infection and lymphoma

The incidence of lymphoma in patients with HIV infection greatly exceeds that of the general population. The increased risk for lymphoma appears related to multiple factors, including the transforming properties of the retrovirus itself, the immunosuppression and cytokine dysregulation that results from the disease, and, most importantly, opportunistic infections with other lymphotrophic herpes viruses such as Epstein-Barr virus and human herpesvirus 8. Histologically lymphomas fall into three groups: (1) those also occurring in immunocompetent patients; (2) those occurring more specifically in HIV-positive patients; and (3) those also occurring in patients with other forms of immunosuppression. Aggressive lymphomas account for the vast majority cases. They frequently present with advanced stage, bulky disease with high tumour burden and, typically, involve extranodal sites. Clinical outcome appears to be worse than in similar aggressive lymphomas in the general population. However, following the introduction of highly active antiretroviral therapy, the risk for developing lymphoma in the context of HIV infection has decreased and the clinical outcome has improved.

Primary effusion lymphoma: a series of 4 cases and review of the literature with emphasis on cytomorphologic and immunocytochemical differential diagnosis

BACKGROUND

Primary effusion lymphoma (PEL) is a human herpes virus-8 (HHV-8)-associated and very rare type of lymphoma usually confined to the body cavities and commonly observed in human immunodeficiency virus (HIV)-infected patients. A comparison was made between the cytologic and immunocytochemical features of 4 cases of PEL encountered in the authors' department with those reported to date in the literature.

METHODS

A comprehensive comparison of the cytologic and immunocytochemical features of the 4 cases with those reported in the literature was conducted.

RESULTS

Cytologically, the most consistent features of the 4 cases and those in the literature included large cell size, moderate to abundant cytoplasm, a single nucleus in most cells with occasional bi- or multinucleated giant cells, single to multiple prominent nucleoli, and coarse chromatin. Immunocytochemically, only 2 (50%) of the current cases were of the null-phenotype compared with 93% of cases in the literature; the other 2 cases had a T-cell phenotype. Activation markers were expressed in 50% and 78% of the current cases and the literature cases, respectively. Positivity for HHV-8 was proven in the 4 cases by immunocytochemistry.

CONCLUSIONS

Cytomorphologically, PEL exhibits features bridging large cell immunoblastic and anaplastic large cell lymphoma. Although it is usually of null-phenotype, it may occasionally express B-cell or T-cell markers, rendering its distinction difficult from other lymphomatous effusions on a cytologic and immunocytochemical basis alone. Therefore, HHV-8 detection is an essential confirmatory ancillary test in suspected cases of PEL.

A case of HHV-8-associated HIV-negative primary effusion lymphoma in Moscow

Primary effusion lymphoma is a rare tumor of B-cell derivation which is associated with human herpes virus type 8 (HHV-8) in 100% and with human immunodeficiency virus (HIV) in most of cases. The paper describes the first case in Russia of HIV(-) HHV-8(+) Epstein-Barr virus (EBV)(+) primary effusion lymphoma in a male patient aged 56 years. The tumor was located in the pleural cavity. Interestingly, the patient was HIV-negative while having a positive tumor HHV-8 test. There are only 22 similar cases described worldwide.

Primary Effusion Lymphoma Involving both Pleural and Abdominal Cavities in a Patient with Hepatitis B Virus-related Liver Cirrhosis

Primary effusion lymphoma (PEL) is an unusual form of non-Hodgkin's lymphoma, which is characterized by lymphomatous effusion in body cavities, but no associated mass lesions. It is usually associated with an immunodeficient state most often with the human immunodeficiency virus (HIV). We describe a 54-year-old man with HIV-negative PEL, with a history of hepatitis B virus-related liver cirrhosis. Both abdominal and pleural cavities were involved; no solid tumor masses were found and bone marrow investigations were normal. The ascites and pleural effusion contained numerous pleomorphic lymphoid cells. Immunophenotyping was positive for CD138. Chromosome study showed complex cytogenetics. The genomic human herpesvirus-8 was detected in the lymphoma cells. It is postulated that the immunosuppressed state in this patient may have been caused by cirrhosis. The patient received four cycles of chemotherapy of CHOP and Picibanil (OK-432) intraperitoneal administration. However, no durable remission was achieved. Adefovir failed to halt the progressive liver failure after the development of YMDD mutant related to lamivudine. He died of sepsis and hepatic failure.

Comparison of human herpes virus 8 related primary effusion lymphoma with human herpes virus 8 unrelated primary effusion lymphoma-like lymphoma on the basis of HIV: report of 2 cases and review of 212 cases in the literature

BACKGROUND

Primary lymphomatous effusion is a rare lymphoma that arises in the body cavity and has a peculiar proliferative form, lacking a tumor. This primary lymphomatous effusion includes human herpes virus 8 (HHV8)-related primary effusion lymphoma (PEL) and HHV8-unrelated PEL-like lymphoma. We attempted to clarify the nature of the primary lymphomatous effusion.

METHODS

Using 'PEL' and 'body cavity-based lymphoma' (BCBL) as key words, reports written in English were collected from PubMed. Primary lymphomatous effusion was defined as BCBL with primary effusion and without tumor at onset. Adding our 2 PEL-like lymphoma cases, each case was studied as to the patients' and lymphomas' characteristics, therapy and survival time. Moreover, each item was compared among four groups according to the presence of HHV8 and HIV.

RESULTS

In 214 cases investigated, there was no difference in proliferation, but an apparent difference in age, gender, phenotype, effectiveness and prognosis among the four groups.

CONCLUSIONS

Both PEL and PEL-like lymphoma are thought to be characterized by a peculiar proliferation, regardless of the presence of HHV8. Dividing PEL or PEL-like lymphoma into two subgroups on the basis of HIV presentation might also be appropriate.

Leukotriene A4 hydrolase expression in PEL cells is regulated at the transcriptional level and leads to increased leukotriene B4 production

Primary effusion lymphoma (PEL) is a herpesvirus-8-associated lymphoproliferative disease characterized by migration of tumor cells to serous body cavities. PEL cells originate from postgerminal center B cells and share a remarkable alteration in B cell transcription factor expression and/or activation with classical Hodgkin's disease cells. Comparative analysis of gene expression by cDNA microarray of BCBL-1 cells (PEL), L-428 (classical Hodgkin's disease), and BJAB cells revealed a subset of genes that were differentially expressed in BCBL-1 cells. Among these, four genes involved in cell migration and chemotaxis were strongly up-regulated in PEL cells: leukotriene A4 (LTA4) hydrolase (LTA4H), IL-16, thrombospondin-1 (TSP-1), and selectin-P ligand (PSGL-1). Up-regulation of LTA4H was investigated at the transcriptional level. Full-length LTA4H promoter exhibited 50% higher activity in BCBL-1 cells than in BJAB or L-428 cells. Deletion analysis of the LTA4H promoter revealed a positive cis-regulatory element active only in BCBL-1 cells in the promoter proximal region located between -76 and -40 bp. Formation of a specific DNA-protein complex in this region was confirmed by EMSA. Coculture of ionophore-stimulated primary neutrophils with BCBL-1 cells leads to an increased production of LTB4 compared with coculture with BJAB and L-428 cells as measured by enzyme immunoassay, demonstrating the functional significance of LTA4H up-regulation.

Dos enfermedades relacionadas con el VHH-8 en un paciente VIH-negativo: sarcoma de Kaposi y enfermedad de Castleman multicéntrica. Respuesta a tratamiento con rituximab y CHOP

Human herpes virus 8 (HHV8) was discovered in 1994 in the biopsy of a Kaposi's sarcoma in a patient with AIDS. Since then it has been identified in all variants of Kaposi's sarcoma and in another two rare disorders: multicentric Castleman's disease and primary body-cavity based lymphomas. The case discusses a 68 year old, HIV-negative male patient, presenting Kaposi's sarcoma for one year and being monitored by dermatology, who presented for weakness, anorexia and fever. On examination, he was found to have adenitis of the lymph nodes in his neck, underarm and groin. A biopsy on one of the swellings led to findings characteristic of multicentric plasma cell variant Castleman's disease. Blood tests for HHV8 and HIV were carried out, resulting positive and negative respectively (IgG anti-HHV8 positive, title 1/640, indirect immunofluorescence). PCR amplification showed HHV8 in peripheral blood. Patient received 8 cycles of CHOP and rituximab, leading to complete disappearance of the adenitis and general symptoms, with no worsening of his Kaposi's sarcoma. Patient remained in complete remission for 10 months after treatment. This paper discusses the case of a HIV-, HHV8+ patient, diagnosed with classic Kaposi's sarcoma, who developed multicentric plasma cell variant Castleman's disease. The coincidence of two or more HHV8-related illnesses in a HIV-negative patient has rarely been described in medical literature. Treatment with rituximab combined with CHOP chemotherapy was effective in this case, and no worsening of the patient's KS was observed.

Human-immunodeficiency-virus-negative, human-herpes-virus-8-negative abdominal cavity primary effusion lymphoma

Primary effusion lymphoma (PEL) is an unusual class of non-Hodgkin's lymphoma, which is characterised by lymphomatous effusions in body cavities, but no associated mass lesions. It is usually associated with an immunodeficient state most often with the human immunodeficiency virus (HIV). We describe a case of a man with HIV-negative, human-herpes-virus-8 (HHV8)-negative PEL, with a history of heavy alcohol intake. The abdominal cavity was the only area involved; no solid tumour masses were observed on scanning, and the bone-marrow investigations were normal. The ascites contained numerous pleomorphic lymphoid, lymphoplasmacytoid cells of B-cell origin. The immunophenotyping was moderately positive for CD 38 and 138, and strongly positive for Ki 67. It is postulated that the immunosuppressed state in this patient may have been caused by the long history of heavy alcohol intake.

Linfoma primário de cavidade pleural em paciente imunocompetente

O linfoma primário de cavidade é um tipo raro de linfoma não-Hodgkin que acomete principalmente pacientes imunocomprometidos e, mais raramente, pacientes imunocompetentes. Neste relato de caso são apresentados os achados clínicos e laboratoriais de um paciente imunocompetente com derrame pleural diagnosticado como linfoma primário de cavidade pleural.

Prognostic Factors and Outcome of Human Herpesvirus 8–Associated Primary Effusion Lymphoma in Patients With AIDS

Purpose

Primary effusion lymphoma (PEL) is a rare high-grade B-cell non-Hodgkin's lymphoma associated with Kaposi sarcoma–associated herpesvirus/human herpesvirus 8 (KSHV/HHV-8) infection, and is mostly observed in the course of HIV infection. The prognosis is poor, with reported median survival time shorter than 6 months. To date, no prognostic factor has been identified in this subset of lymphoma.

Patients and Methods

We describe here a large series of HIV-infected patients with PEL, including 28 cases diagnosed in six centers during an 11-year time period. Prognosis analysis was performed using a Cox proportional hazard regression model. Statistically significant covariates were further analyzed in a forward, stepwise multivariate model.

Results

After a median follow-up of 3.8 years (range, 10 months to 10.8 years), nine patients (32%) were still alive, and eight of them remained progression free. The median survival was 6.2 months, and the 1-year overall survival rate was 39.3%. Fourteen patients (50%) achieved complete remission, with a 1-year disease-free survival rate at 78.6%. In a multivariate analysis, only a performance status more than 2 (hazard ratio, 5.84; 95% CI, 1.76 to 19.33) and the absence of highly active antiretroviral therapy (HAART) before PEL diagnosis (hazard ratio, 3.26; 95% CI, 1.14 to 9.34) were found to be independent predictors for shorter survival.

Conclusion

Based on a retrospective series of 28 patients, two prognostic factors were identified as being independently associated with impaired clinical outcome in HIV-related PEL—(1) a poor performance status and (2) the absence of HAART before PEL diagnosis.

HHV-8-Associated T-Cell Lymphoma in a Lymph Node With Concurrent Peritoneal Effusion in an HIV-Positive Man

Primary effusion lymphoma (PEL) is an uncommon large cell lymphoma, usually seen in human immunodeficiency virus (HIV)-infected patients. PEL is characterized by various clinical, histomorphologic, and immunophenotypical features, and is associated with the human herpes virus 8 (HHV-8). PEL may present as either a body cavity-based lymphomatous effusion or a solid tumor mass. Most so-called "solid PEL" usually have an extranodal location; exceptionally rarely, they occur in lymph nodes. The majority of PEL consist of malignant cells of B-cell genotype; seldom they are of T-cell origin. We report a rare case of HHV-8-associated "solid PEL" of T-cell type in a 41-year-old HIV-seropositive man with a concomitant peritoneal effusion. The T-cell lymphoma was diagnosed on the basis of morphologic, immunophenotypic, and molecular findings of a lymph node biopsy. The tumor cells strongly expressed CD45R0, CD7, CD43, MUM1/IRF4, CD30, HHV-8, and EBER, and demonstrated a clonal rearrangement of T-cell receptor-gamma chain gene. The following case provides another example of a lymph node-based "solid" PEL, demonstrating the variety within the spectrum of HHV-8-associated lymphoma.