Chromosomal and comparative genomic analyses of HHV-8-negative primary effusion lymphoma in five HIV-negative Japanese patients

Fluid Overload-Associated Large B-Cell Lymphoma: A Case Report and Review of Literature

Fluid overload-associated large B-cell lymphoma (FO-LBCL) is a new entity described in the fifth edition of the World Health Organization (WHO) Classification of Hematolymphoid Tumors (WHO-HAEM5). It refers to malignant lymphoma present with symptoms of serous effusions in body cavities (pleural, peritoneal, and/or pericardial) in the absence of an identifiable tumor mass. We present a case of an 82-year-old man with a history of atrial fibrillation and atrial flutter, status post-ablation, essential hypertension (HTN), hyperlipidemia (HLD), and diabetes mellitus (DM) type 2 who was referred to our hospital for shortness of breath due to recurrent pleural effusion. Right video-assisted thoracoscopy with right pleural biopsy was performed. Histopathological examination of the pleural biopsy revealed dense fibrous tissue, chronic inflammation, lymphoid aggregates, and granulation tissue, with no evidence of lymphoma. Cytology of the right pleural fluid revealed large lymphoid cells, which were positive for CD45, CD20, PAX-5, MUM-1, BCL2, BCL6, and MYC protein. They were negative for CD3, CD10, CD138, and HHV-8 by immunohistochemistry (IHC). Epstein-Barr virus (EBV) was negative by in situ hybridization (ISH). Due to the absence of any evidence of lymphoma elsewhere, a diagnosis of fluid overload-associated large B-cell lymphoma (FO-LBCL) was made. We provide a synopsis of the main clinicopathological features of FO-LBCL and the two main differential diagnoses, primary effusion lymphoma (PEL) and diffuse large B-cell lymphoma (DLBCL).

HHV8 and EBV-negative primary effusion-based lymphoma: A case report of a new provisional entity and review of literature

Key Clinical Message

HHV8- and EBV-negative primary effusion lymphoma is an extremely rare neoplasm involving body cavities without detectable tumor mass. It usually presents in elderly patients without known immunodeficiency. Compared to primary effusion lymphoma, it has a better prognosis.

Primary effusion lymphoma (PEL) is a rare non-Hodgkin lymphoma confined exclusively to body cavities without detectable tumor masses. The term PEL-like is an entity similar to PEL in clinical presentation but without relation to human herpesvirus 8 (HHV8). We report a case of HHV8- and EBV-negative primary effusion-based lymphoma.

Human herpesvirus 8-negative effusion-based large B-cell lymphoma: a distinct entity with unique clinicopathologic characteristics

Rare cases of human herpesvirus 8 (HHV8)-negative effusion-based large B-cell lymphoma (EB-LBCL) occur in body cavities without antecedent or concurrent solid mass formation. In contrast to HHV8 + primary effusion lymphoma (PEL), EB-LBCL has no known association with HIV or HHV8 infection. However, the small sample sizes of case reports and series worldwide, especially from non-Japanese regions, have precluded diagnostic uniformity. Therefore, we conducted a retrospective, multi-institutional study of 55 cases of EB-LBCL and performed a comprehensive review of an additional 147 cases from the literature to identify distinct clinicopathologic characteristics. In our study, EB-LBCL primarily affected elderly (median age 80 years), immunocompetent patients and manifested as lymphomatous effusion without a solid component. The lymphomatous effusions mostly occurred in the pleural cavity (40/55, 73%), followed by the pericardial cavity (17/55, 31%). EB-LBCL expressed CD20 (53/54, 98%) and PAX5 (23/23, 100%). Most cases (30/36, 83%) were of non-germinal center B-cell subtype per the Hans algorithm. HHV8 infection was absent (0/55, 0%), while Epstein-Barr virus was detected in 6% (3/47). Clinically, some patients were managed with drainage alone (15/34, 44%), while others received rituximab alone (4/34, 12%) or chemotherapy (15/34, 44%). Eventually, 56% (22/39) died with a median overall survival (OS) of 14.9 months. Our findings were similar to those from the literature; however, compared to the non-Japanese cases, the Japanese cases had a significantly higher incidence of pericardial involvement, a higher rate of chemotherapy administration, and longer median OS. Particularly, we have found that Japanese residence, presence of pericardial effusion, and absence of MYC rearrangement are all favorable prognostic factors. Our data suggest that EB-LBCL portends a worse prognosis than previously reported, although select patients may be managed conservatively. Overall, EB-LBCL has distinct clinicopathologic characteristics, necessitating the establishment of separate diagnostic criteria and consensus nomenclature.

Primary Effusion Lymphoma: A Timely Review on the Association with HIV, HHV8, and EBV

Primary effusion lymphoma (PEL) is defined by the WHO classification as a large B-cell neoplasm without detectable tumor masses. It is universally associated with HHV8, with most cases occurring in the setting of immunodeficiency such as HIV infection, and a poor prognosis. Morphologically, the neoplastic cells range from immunoblastic, plasmablastic, to anaplastic; and phenotypically, most cases express plasma cell but not B-cell markers, i.e., plasmablastic. During the past decade, primary HHV8-negative effusion lymphoma has been reported. Such cases were considered in the WHO classification scheme as effusion-based lymphoma. We performed a systemic review of 167 HHV8-negative effusion lymphomas from the literature and found that only 42% were associated with a fluid overload state, and with low rates of HIV (6%) or EBV (21%) infection. Furthermore, most patients are old (or immunosenescent) with underlying medical conditions/comorbidities, most neoplasms are of B-cell phenotype, and the outcome is more favorable than that of HHV8-positive PEL. These distinctive findings supported our prior proposal of designating these HHV8-negative cases as type II PEL, in contrast to the classic or type I PEL as defined by the WHO. Furthermore, we propose an algorithmic approach for the diagnosis of PEL and its mimickers.

Development of a novel cell line-derived xenograft model of primary herpesvirus 8-unrelated effusion large B-cell lymphoma and antitumor activity of birabresib in vitro and in vivo

BACKGROUND

Primary human herpesvirus 8 (HHV8)-unrelated effusion large B-cell lymphoma is a clinical disease entity distinct from HHV8-positive primary effusion lymphoma (PEL). However, the lack of experimental HHV8-unrelated effusion large B-cell lymphoma models continues to hinder the pathophysiologic and therapeutic investigations of this disorder.

METHODS

The lymphoma cells were obtained from the pleural effusion of a patient with primary HHV8-unrelated effusion large B-cell lymphoma and cultured in vitro.

RESULTS

We established a novel HHV8-unrelated effusion large B-cell lymphoma cell line, designated Pell-1, carrying a c-MYC rearrangement with features distinct from those of HHV8-positive PEL. Moreover, we developed an HHV8-unrelated effusion large B-cell lymphoma cell line-derived xenograft model. Pell-1 cells induced profuse lymphomatous ascites and subsequently formed intra-abdominal tumors after intraperitoneal implantation into irradiated nonobese diabetic/severe combined immunodeficient mice. Thus, this xenograft mouse model mimicked the clinical phenomena observed in patients and recapitulated the sequential stages of aggressive HHV8-unrelated effusion large B-cell lymphoma. The bromodomain and extraterminal domain (BET) inhibitors JQ1 and birabresib (MK-8628/OTX015) reduced the proliferation of Pell-1 cells in vitro through the induction of cell cycle arrest and apoptosis. The antitumor effect of BET inhibition was also demonstrated in vivo, as birabresib significantly reduced ascites and suppressed tumor progression without apparent adverse effects in the xenografted mice.

CONCLUSION

These preclinical findings suggest the therapeutic potential of targeting c-MYC through BET inhibition in HHV8-unrelated effusion large B-cell lymphoma.

Primary HHV-8 (-) Effusion-Based Non-Germinal Center B Cell Diffuse Large B Cell Lymphoma Successfully Treated with Standard Anthracycline-Based Chemoimmunotherapy

Effusion-based lymphomas (EBL) are usually high-grade B cell non-Hodgkin’s lymphomas which involve effusion fluid in a body cavity, typically presenting as a pleural effusion, without evidence of disease elsewhere. They are most frequently seen in HIV-infected individuals and are biologically driven by human herpesvirus-8 virus (HHV-8). HHV-8 (+) EBL is recognized as primary effusion lymphoma (PEL) under the World Health Organization classification. HHV-8 (-) EBL has been reported in association with Hepatitis C virus (HCV) infection, Epstein-Barr virus (EBV) infection, fluid overload, liver cirrhosis, renal dysfunction, cardiac arrhythmias, myocardial infarction, and heart failure. These cases can be labeled as primary EBL (PEBL). We describe a non-germinal center B cell diffuse large B cell lymphoma (NGCB-DLBCL) presenting as PEBL in an immunocompetent 81-year-old male who had an extensive cardiac history and tested negative for HIV, HHV-8, and EBV. He was treated with thoracentesis and standard anthracycline-based chemoimmunotherapy and has remained in complete remission for over 5 ½ years since his original diagnosis. Our case indicates that NGCB-DLBCL can present as PEBL and is potentially curable with the standard chemoimmunotherapeutic approach.

[Human herpesvirus 8-unrelated primary effusion lymphoma-like lymphoma that developed during myelodysplastic syndrome]

Primary effusion lymphoma (PEL) is a large B-cell lymphoma that only proliferates proliferating effusion in the body cavity. It is associated with human herpesvirus 8 (HHV8).HHV8 negative effusion lymphoma, which is different from PEL in many ways, has also been reported and is referred to as HHV8-unrelated PEL-like lymphoma. This lymphoma is very rare and its clinical characteristics have not been fully clarified.A 79-year-old male developed HHV8-negative primary effusion lymphoma during treatment for myelodysplastic syndrome.Abdominal computed tomography revealed abdominal effusion, but did not show any evidence of a tumor mass or lymph node enlargement. A cytological analysis of his pleural effusion revealed atypical lymphoid cells that were negative for CD10, and positive for CD19 and CD20. Corticosteroids were administered to treat the abdominal effusion; however, the patient died of an exacerbation of lymphoma on the 20th day after the initiation of corticosteroid therapy. We herein report the case of an HIV seronegative elderly patient with HHV8-unrelated PEL-like lymphoma.

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.

Human herpesvirus 8-negative effusion-based lymphoma with indolent clinical behavior in an elderly patient: A case report and literature review

Primary effusion lymphoma (PEL) is a B-cell non-Hodgkin's lymphoma that is usually characterized by lymphomatous effusions in the body cavity without any detectable tumor masses. According to the World Health Organization (WHO) schema for tumor classification, PEL is defined by the presence of human herpesvirus 8 (HHV8) in malignant lymphoid cells. However, a subset of effusion-based B-cell lymphoma is not HHV8-positive and exhibits different clinicopathological characteristics. The 2017 WHO Classification of Tumors of Hematopoietic and Lymphoid Tissues does not list HHV8-negative effusion-based lymphoma, which remains an underappreciated B-cell lymphoma, as an individual entity. The present study reports a case of this rare type of lymphoma with indolent clinical behavior in a 75-year-old male patient receiving only symptomatic treatment. Additionally, a review of similar cases reported in the English literature is presented.

Age and CD20 Expression Are Significant Prognostic Factors in Human Herpes Virus-8-negative Effusion-based Lymphoma

Human herpes virus-8 (HHV-8)-negative effusion-based lymphoma (HHV-8-negative EBL) can be distinguished from primary effusion lymphoma based on clinical and pathologic findings. Although the morphology between the 2 is similar and they both originate from body cavities with serous effusions and are characterized by lack of tumor masses, HHV-8-negative EBL generally occurs in older patients, and has favorable response to therapy and better prognosis than primary effusion lymphoma. However, no systematic studies have investigated prognostic factors in patients with HHV-8-negative EBL. In this report, clinical and pathologic characteristics of 67 cases of HHV-8-negative EBL, including 2 of our own cases, were analyzed. Univariate analyses revealed older age (70 y and above), Japanese ethnicity, pericardial effusion, CD20 expression, and chemotherapy with rituximab were significantly favorable prognostic factors. Peritoneal effusion was identified as an unfavorable prognostic factor. In the multivariate analysis, age and CD20 expression were independent prognostic factors (P=0.013 and 0.003, respectively). A past history of induced fluid overload, hepatitis C viral infection, and peritoneal effusion were significantly correlated with patients aged below 70 years, while pericardial and pleural effusions were significantly correlated with patients aged 70 years and above. A comparison of cases with and without CD20 expression revealed that Japanese ethnicity and pericardial effusion were significantly correlated with CD20 expression, whereas a past history of induced fluid overload and peritoneal effusion were significantly correlated with the absence of CD20. We concluded that older age and CD20 expression are significant and favorable independent prognostic factors of HHV-8-negative EBL.

Primary effusion lymphoma in Taiwan shows two distinctive clinicopathological subtypes with rare human immunodeficiency virus association

AIMS

To investigate the clinicopathological and molecular features of primary effusion lymphoma (PEL) in Taiwan and the association with human immunodeficiency virus (HIV), human herpesvirus 8 (HHV8) and Epstein-Barr virus (EBV).

METHODS AND RESULTS

We investigated retrospectively 26 cases with a median age of 76.5. Only one (4%) patient was infected with HIV. Cytologically, all lymphoma cells revealed typical immunoblastic to plasmablastic morphology. Immunohistochemically, HHV8 was positive in eight (32%) tumours and negative in 17 (68%) cases. All 23 tested cases examined were of the non-germinal-centre B cell phenotype. MYC proto-oncogene (MYC) and Epstein-Barr encoding mRNA (EBER) were positive in 43% (nine of 21) and 17% (four of 23) cases, respectively. Immunoglobulin heavy chain (IGH), B cell lymphoma (BCL)2, BCL6 and MYC were rearranged in 71%, 11%, 12% and 18% cases, respectively. By univariate analysis, the overall survival (OS) was associated statistically with MYC expression (P = 0.012) and BCL2 rearrangement (P = 0.035), but not with the others. By multivariate analysis, no factor was statistically significant. Compared to the HHV8-negative cases, the HHV8-positive cases were mainly of the plasmablastic immunophenotype expressing CD30 and CD138, and with a less frequent expression of pan-B cell markers.

CONCLUSIONS

Apart from the phenotypical difference, our HHV8-positive neoplasms were not distinct from the HHV8-negative group. Literature review of 256 cases, including our cases, revealed that HHV8-positive cases were associated more frequently with HIV and EBV infection, with rare MYC rearrangement, and a poorer prognosis than HHV8-negative cases. We propose to name the HHV8-positive cases as 'classical' or 'type I PEL' and the HHV8-negative cases as 'type II PEL', stressing the similarities and the distinctive features between these two groups.

Interleukin 1 receptor-associated kinase 1 (IRAK1) mutation is a common, essential driver for Kaposi sarcoma herpesvirus lymphoma

Primary effusion lymphoma (PEL) is an AIDS-defining cancer. All PELs carry Kaposi sarcoma-associated herpesvirus (KSHV). X chromosome-targeted sequencing of PEL identified 34 common missense mutations in 100% of cases. This included a Phe196Ser change in the interleukin 1 receptor-associated kinase 1 (IRAK1). The mutation was verified in primary PEL exudates. IRAK1 is the binding partner of MyD88, which is mutated in a fraction of Waldenström macroglobulinemia. Together, these two mediate toll-like receptor (TLR) signaling. IRAK1 was constitutively phosphorylated in PEL and required for survival, implicating IRAK1 and TLR signaling as a driver pathway in PEL and as a new drug development target.

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.

Human herpesvirus 8-unrelated primary effusion lymphoma-like lymphoma: report of a rare case and review of 54 cases in the literature

OBJECTIVES

To report a patient with primary effusion lymphoma who was negative for human herpesvirus-8 (HHV-8), human immunodeficiency virus, Epstein-Barr virus, hepatitis C virus, and hepatitis B virus, as well as review 54 reported cases of HHV-8-unrelated primary effusion lymphoma (PEL)-like lymphoma in the literature to clarify the nature of this entity.

METHODS

The patients' characteristics, clinical presentation, pathogenesis, morphologic-immunophenotypic features, clinical management, and prognosis were studied.

RESULTS

HHV-8-negative PEL-like lymphomas often occur in immunocompetent and elderly patients, are sometimes associated with chronic inflammation-related fluid overload, are mostly large B-cell or large B-cell with plasmacytic differentiation type, and are associated with a better prognosis.

CONCLUSIONS

In various aspects, HHV-8-unrelated PEL-like lymphoma is a different entity from HHV-8-related PEL. Immunophenotype, morphology, and c-myc/8q24 status should be included for differential diagnosis. A test for c-myc or 8q24 abnormalities should be recommended for subdividing HHV-8-unrelated PEL-like lymphoma, which may have benefits in patient management.

Kaposi sarcoma herpesvirus/human herpesvirus-8-negative effusion-based lymphoma: report of 3 cases and review of the literature

BACKGROUND

Primary effusion lymphoma (PEL) is a rare subtype of large B-cell lymphoma that arises in body cavities without detectable tumor masses. PEL is universally associated with Kaposi sarcoma herpesvirus (KSHV)/human herpesvirus-8 (HHV8). Despite overlapping features, KSHV/HHV8-negative effusion-based lymphoma is a distinct entity from PEL. To date, 52 cases have been reported. The authors report 3 additional cases received in their laboratory from 2007 to 2012.

METHODS

Clinical data, cytomorphologic features, and immunophenotypic features of the 3 cases were described and compared with those reported in the literature.

RESULTS

The cells in HHV8-negative effusion lymphoma commonly revealed large cell, immunoblastic morphology and B-cell immunophenotype. The 3 cases demonstrated cytomorphologic and immunophenotypic variability. Cytomorphologically, 1 case contained large, highly atypical cells with a moderate amount of cytoplasm, round nucleus, coarsely granular chromatin, and a single macronucleolus. The other 2 cases had medium to large atypical cells with high nuclear-to-cytoplasmic ratios, slightly irregular to cleaved nuclei, and multiple conspicuous nucleoli. One case had a null phenotype with aberrant cytokeratin expression. B-cell phenotype was established by clonal immunoglobulin heavy-chain rearrangement using polymerase chain reaction, whereas the other 2 cases demonstrated a B-cell phenotype by flow cytometry and immunohistochemical staining. All 3 cases were negative for both HHV8 and Epstein-Barr virus.

CONCLUSIONS

HHV8-negative effusion lymphoma exhibits clinical, cytomorphologic, and immunophenotypic variability. Cases with a null-phenotype can be particularly challenging. When effusion lymphoma is suspected, ancillary tests are helpful. Moreover, HHV8 detection is critical in differentiating PEL and HHV8-negative effusion lymphoma, because they have overlapping features yet different prognoses.

KSHV/HHV8-negative effusion-based lymphoma, a distinct entity associated with fluid overload states

Human herpesvirus-8 (HHV8)-positive effusion-based lymphomas have been termed primary effusion lymphoma (PEL) in the WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. Kaposi sarcoma herpesvirus (KSHV)/HHV8-negative effusion-based lymphomas (KSHV/HHV8-negative EBLs) resembling PELs have been reported in the literature and in many cases have been (mis)classified as PEL-like lymphomas. Herein, we present a series of cases and a review of KSHV/HHV8-negative EBLs. This lymphoma, although cytomorphologically resembling PEL, is a distinct entity with characteristic clinical and pathologic features. Patients are older, generally human immunodeficiency virus negative and not immunosuppressed, frequently hepatitis C positive compared with the population baseline, and often have an underlying medical condition leading to fluid overload. The lymphoma cells express pan-B-cell antigens in 86.7%, and CD20 is expressed in 71.1% of the cases. The lymphoma is often of germinal center B or mixed germinal center B/activated B-cell signature with the Hans classifier, and Epstein-Barr virus is positive in nearly 30% of cases. Rare T-cell lymphomas were also reported. Clinical outcomes and response to therapy, including isolated aspiration, are relatively favorable compared with cases of PEL. We suggest that HHV8-negative effusion-based lymphoma is a distinct entity associated with fluid overload states.

HHV8-Negative Primary Effusion Lymphoma of B-Cell Lineage: Two Cases and a Comprehensive Review of the Literature

Primary effusion lymphoma (PEL) is a rare extranodal lymphoma that typically presents in a body cavity in the absence of a detectable tumor mass and that occurs predominantly in immunosuppressed individuals. The neoplastic lymphoid cells are frequently infected with human herpes virus 8 (HHV8), also known as Kaposi sarcoma herpes virus (KSHV). We describe two HIV-negative patients who presented with primary effusion lymphoma of B-cell lineage involving the pleural cavity, but whose tumor cells lacked infection by HHV8. We review the English language literature of HHV8-negative PEL of B-cell lineage and compare these lymphomas to HHV8-associated PEL with regard to clinical and pathological characteristics, therapy, and outcome.

Genomic profiling using array comparative genomic hybridization define distinct subtypes of diffuse large B-cell lymphoma: a review of the literature

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin Lymphoma comprising of greater than 30% of adult non-Hodgkin Lymphomas. DLBCL represents a diverse set of lymphomas, defined as diffuse proliferation of large B lymphoid cells. Numerous cytogenetic studies including karyotypes and fluorescent in situ hybridization (FISH), as well as morphological, biological, clinical, microarray and sequencing technologies have attempted to categorize DLBCL into morphological variants, molecular and immunophenotypic subgroups, as well as distinct disease entities. Despite such efforts, most lymphoma remains undistinguishable and falls into DLBCL, not otherwise specified (DLBCL-NOS). The advent of microarray-based studies (chromosome, RNA, gene expression, etc) has provided a plethora of high-resolution data that could potentially facilitate the finer classification of DLBCL. This review covers the microarray data currently published for DLBCL. We will focus on these types of data; 1) array based CGH; 2) classical CGH; and 3) gene expression profiling studies. The aims of this review were three-fold: (1) to catalog chromosome loci that are present in at least 20% or more of distinct DLBCL subtypes; a detailed list of gains and losses for different subtypes was generated in a table form to illustrate specific chromosome loci affected in selected subtypes; (2) to determine common and distinct copy number alterations among the different subtypes and based on this information, characteristic and similar chromosome loci for the different subtypes were depicted in two separate chromosome ideograms; and, (3) to list re-classified subtypes and those that remained indistinguishable after review of the microarray data. To the best of our knowledge, this is the first effort to compile and review available literatures on microarray analysis data and their practical utility in classifying DLBCL subtypes.

Although conventional cytogenetic methods such as Karyotypes and FISH have played a major role in classification schemes of lymphomas, better classification models are clearly needed to further understanding the biology, disease outcome and therapeutic management of DLBCL. In summary, microarray data reviewed here can provide better subtype specific classifications models for DLBCL.

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.

Tumor suppressor genes FHIT and WWOX are deleted in primary effusion lymphoma (PEL) cell lines

Primary effusion lymphoma (PEL) is a diffuse-large B-cell lymphoma with poor prognosis. One hundred percent of PELs carry the genome of Kaposi sarcoma-associated herpesvirus and a majority are coinfected with Epstein-Barr virus (EBV). We profiled genomic aberrations in PEL cells using the Affymetrix 6.0 SNP array. This identified for the first time individual genes that are altered in PEL cells. Eleven of 13 samples (85%) were deleted for the fragile site tumor suppressors WWOX and FHIT. Alterations were also observed in the DERL1, ETV1, RASA4, TPK1, TRIM56, and VPS41 genes, which are yet to be characterized for their roles in cancer. Coinfection with EBV was associated with significantly fewer gross genomic aberrations, and PEL could be segregated into EBV-positive and EBV-negative clusters on the basis of host chromosome alterations. This suggests a model in which both host genetic aberrations and the 2 viruses contribute to the PEL phenotype.

Gray zones around diffuse large B cell lymphoma. Conclusions based on the workshop of the XIV meeting of the European Association for Hematopathology and the Society of Hematopathology in Bordeaux, France

The term "gray-zone" lymphoma has been used to denote a group of lymphomas with overlapping histological, biological, and clinical features between various types of lymphomas. It has been used in the context of Hodgkin lymphomas (HL) and non-Hodgkin lymphomas (NHL), including classical HL (CHL), and primary mediastinal large B cell lymphoma, cases with overlapping features between nodular lymphocyte predominant Hodgkin lymphoma and T-cell/histiocyte-rich large B cell lymphoma, CHL, and Epstein-Barr-virus-positive lymphoproliferative disorders, and peripheral T cell lymphomas simulating CHL. A second group of gray-zone lymphomas includes B cell NHL with intermediate features between diffuse large B cell lymphoma and classical Burkitt lymphoma. In order to review controversial issues in gray-zone lymphomas, a joint Workshop of the European Association for Hematopathology and the Society for Hematopathology was held in Bordeaux, France, in September 2008. The panel members reviewed and discussed 145 submitted cases and reached consensus diagnoses. This Workshop summary is focused on the most controversial aspects of gray-zone lymphomas and describes the panel's proposals regarding diagnostic criteria, terminology, and new prognostic and diagnostic parameters.

Primary effusion lymphoma involving three body cavities

Primary effusion lymphoma (PEL) is a human herpes virus-8 (HHV8)-associated large-cell non-Hodgkin lymphoma localized in body cavities and presenting as pleural, peritoneal, or pericardial lymphomatous effusions. It typically affects immunocompromised patients and usually involves only one body site. We describe herein a case of PEL affecting three body cavity sites in an immunocompetent patient. A 69-year-old HIV-negative man presented with upper gastrointestinal bleeding and ascites. An examination of the fluid by cytology showed large atypical lymphocytes with abundant basophilic cytoplasm, either central or eccentric nuclei having irregular outlines, and multiple prominent nucleoli. The neoplastic cells showed positive staining for CD45, CD3, HHV8 latent nuclear antigen (LNA), and Epstein-Barr virus-encoded RNA. A diagnosis of PEL was rendered. Despite chemotherapy and valganciclovir, the disease progressed to involve the pleural and pericardial cavities and the patient died 5 months following the initial diagnosis. Although PEL is a B-cell lymphoma, it is usually of null phenotype by immunohistochemistry, and can rarely aberrantly express T-cell markers, as seen in the current case. The key to the diagnosis of PEL rests on identifying HHV8 in the neoplastic cells. Therefore, restricting the term of PEL only to those cases that are HHV8 positive is important in order to differentiate PEL from other lymphomas that can present as serous effusions and that carry, in general, a more favorable prognosis than PEL.

Human herpesvirus 8-negative malignant effusion lymphoma: A distinct clinical entity and successful treatment with rituximab

We describe 2 elderly patients with Human herpesvirus 8 (HHV-8)/Kaposi sarcoma herpes virus negative malignant effusion lymphoma showing pan-B-cell immunophenotyping markers and successfully treated with a chimeric anti-CD20 IgG1 monoclonal antibody, rituximab. A 90-year-old man and an 87-year-old woman were hospitalized because of pleural effusions. They were diagnosed as having malignant effusion lymphoma on the basis of cytologic and flow cytometric findings of effusions, revealing involvement of atypical lymphoid cells and expression of CD19 and CD20. The former case was intolerant of chemotherapy because of toxicity. Using the conventional dose of rituximab, they showed neither intolerance nor adverse effects and their pleural effusions decreased immediately. Any sign of disease progression was not noted in either of the patients. They were negative for a HHV-8 infection and had no history of pyothorax. This type of lymphoma was not compatible with primary effusion lymphoma (PEL) defined by World Health Organization Classification of Tumors or pyothorax-associated lymphoma. We diagnosed these patients as having "HHV-8 negative malignant effusion lymphoma". HHV-8 negative malignant effusion lymphoma may be a new clinicopathologic and biologic entity. Because most of the cases were positive for pan-B-cell markers, rituximab may be a promising agent for the treatment.

Report of an HIV and HHV-8 negative case of primary effusion lymphoma with idiopathic T4 lymphocytopenia

Although primary effusion lymphoma (PEL) is usually associated with human herpes virus-8/Kaposi sarcoma herpes virus (HHV-8/KSHV) and human immunodeficiency virus (HIV), there are several reports of HHV-8/KSHV and HIV negative cases, mainly in the setting of immunodeficiency. Here, we report the second case of PEL associated with idiopathic T4 lymphocytopenia (ICL), which was HHV-8/KSHV negative, HIV negative and Epstein-Barr virus positive, while no other causative agents for immunodeficiency were documented. Flow cytometry revealed a hyperdiploid and highly mitotic large B-cell population, CD30, EMA, CD66, CD38 and CD71 positive. The malignant lymphoma cells showed atypia with prominent nuclei and basophilic vacuolated cytoplasm, while cytogenetic analysis with fluorescent in situ hybridization showed trisomy 18. The patient was administered R-COP chemotherapy, but no remission was achieved, up to 3 months from diagnosis.

Human herpes virus 8-unrelated primary effusion lymphoma-like lymphoma: report of a rare case and review of the literature

A rare case of human herpes virus 8-unrelated primary effusion lymphoma-like lymphoma: a report and review of the literature. APMIS 2009; 117:222-29. Primary effusion lymphoma (PEL) is a very rare type of lymphoma usually confined to the body cavities predominantly in immunosuppressed patients infected with human herpes virus 8 (HHV-8). The new term for HHV-8 independent PEL is HHV8-unrelated PEL-like lymphoma. We describe an 89-year-old human immunodeficiency virus (HIV)-negative male patient with HHV8-unrelated PEL-like lymphoma in the pleura. No hepatosplenomegaly or lymphadenopathy was detected. Chest radiography and computed tomography revealed right pleural effusion, but no evidence of tumor mass or lymph node enlargement. Cytological analysis of the pleural effusion revealed a high-grade lymphoma with round nuclei, prominent nucleoli and abundant cytoplasm with immunophenotypes positive for CD45, CD30, CD38, CD7 and CD71. Because of the advanced age, no chemotherapy was given. Effusion resolved spontaneously. One year after the diagnosis, a new pleural effusion developed at the left side. Following thoracentesis and pleurodesis, the patient remained in complete remission for 40 months. To date, 30 cases of HHV8-unrelated PEL-like lymphoma/HIV negative have been reported in the literature. The outcome of the HHV8-unrelated PEL-like lymphoma patients who were HIV negative seems to be better than HIV- and HHV-8-positive PEL.

HHV-8/KSHV-negative and CD20-positive primary effusion lymphoma successfully treated by pleural drainage followed by chemotherapy containing rituximab

The present patient was diagnosed as having human herpes virus-8 (HHV-8)/Kaposi sarcoma herpes virus (KSHV)-negative and CD20-positive primary effusion lymphoma (PEL) of the right-sided pleural effusion. After pleural drainage, malignant cells disappeared spontaneously in a small amount of the remaining pleural effusion without chemotherapy. The patient was treated with six cycles of chemotherapy consisting of rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone. He has been in complete remission for more than 22 months. It is suggested that effusion drainage followed by chemotherapy containing rituximab is a potential treatment strategy for patients with HHV-8/KSHV-negative and CD20-positive PEL.

Establishment of a human herpes virus-8-negative malignant effusion lymphoma cell line (STR-428) carrying concurrent translocations of BCL2 and c-MYC genes

A new cell line, STR-428 was established from ascites tumor cells of a malignant effusion lymphoma patient without human herpes virus-8 (HHV-8) infection. STR-428 cells showed an immunophenotype of mature B-cells and produced few cytokines related to lymphomatous effusion. Karyotypic and genetic analysis revealed complex translocations including t(14;18)(q32;q21) effecting IgH/BCL2 and der(8)t(3;8)(q27;q24) involving c-MYC. STR-428 represents a unique, B-cell lymphoma cell line carrying concurrent rearrangement of BCL2 and c-MYC genes with features distinct from those of HHV-8-related primary effusion lymphoma. This cell line may be a valuable tool, other than HHV-8, to investigate the pathogenesis of primary lymphomatous effusion.

Recurrent genomic imbalances in primary effusion lymphomas

Primary effusion lymphomas (PEL) form a subset of AIDS-related lymphomas and usually have a poor prognosis. Although Kaposi's sarcoma-associated herpes virus (KSHV) is often associated with PEL, very little is known about the exact mechanisms or causative effects of these associations. We investigated the chromosomal imbalances in six KSHV-positive PEL cell lines using comparative genomic hybridization analysis. We defined the shortest regions of overlaps for genomic gains on six chromosomes: 1q31, 4q31 approximately q33, 7q10 approximately q21, 8q21.1, 12q0 approximately q23, and Xp11 approximately q21. The recurrent nature of the gains found in these chromosomal regions suggests that these imbalances play roles in the pathogenesis of PEL.

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.

Genomic imbalances in AIDS-related lymphomas: relation with tumoral Epstein-Barr virus status

BACKGROUND

The pathologic heterogeneity of AIDS related lymphomas (ARL) reflects several pathogenic mechanisms: chronic antigenic stimulation, Epstein-Barr virus (EBV) infection, and genomic abnormalities. Genetic abnormalities, known to play a major role in lymphomas of non-immunocompromised patients, are not well characterized in ARL.

OBJECTIVE

Characterization of the DNA copy number change (CNC) in ARL and comparison of our findings with tumoral EBV and immune status.

DESIGN AND METHODS

We have studied by comparative genomic hybridization (CGH), 28 ARL well characterized for histopathologic, clonality and EBV findings.

RESULTS

DNA-CNC were detected in 50% of cases. Gains of chromosomal material were much more frequent than losses and involved chromosomes 9p, 11q, 12q, 17q, and 19q recurrently. DNA-CNC tended to be more frequent in EBV-positive lymphomas with latency type II/III than in EBV-positive latency I or EBV-negative lymphomas. Most chromosomal regions affected in HIV-related lymphoma were similar to those already reported in HIV-negative lymphomas.

CONCLUSION

This CGH study allowed the identification of non-random chromosomal alterations in ARL. The results suggested an inverse relationship between EBV infection (latency II/III), associated with deep acquired immune suppression, and the number of chromosomal alterations which may be explained by a direct role of viral proteins in lymphomagenesis by activation of signalling pathways without needing several genomic alterations.

Successful Eradication of Relapsed Primary Effusion Lymphoma with High-Dose Chemotherapy and Autologous Stem Cell Transplantation in a Patient Seronegative for Human Immunodeficiency Virus

Primary effusion lymphoma (PEL) is a recently recognized disease that occurs most often in immunosuppressed patients, either with human immunodeficiency virus (HIV) or in the posttransplantation setting, and it occasionally occurs in nonimmunosuppressed patients. Patients present with lymphomatous effusions in serous cavities--pleura, pericardium, or peritoneum--without any identifiable tumor mass. PEL rarely responds to systemic chemotherapy, and the prognosis is poor, with a median survival time of less than 6 months for most cohorts. A standard treatment for PEL has not yet been identified. We describe a patient with HIV-seronegative PEL who relapsed after combination chemotherapy and then underwent successful treatment with high-dose chemotherapy (HDC) and autologous stem cell transplantation (ASCT). The treatment was well tolerated, and the patient has been in remission for 12 months after HDC and ASCT.

An unusual cause of pleural effusion

Primary effusion lymphoma (PEL) is a unique clinicopathological entity associated with human herpesvirus-8 (HHV-8) infection, occurring almost exclusively in human immunodeficiency virus (HIV)-infected individuals. We report a rare case of HHV-8-negative PEL in an HIV-negative elderly patient who presented with pleural effusion. The patient was treated with CHOP and Rituximab. As opposed to the general poor outcome of this disease, our patient achieved complete remission and is still without signs of disease 11 months after the last treatment.

Serous effusions in malignant lymphomas: A review

Serous effusions are a common complication of lymphomas. Although the frequency of pleural effusion is 20-30% in non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD), the involvement of peritoneal and pericardial cavities is uncommon. Among lymphoma subtypes, T-cell neoplasms, especially the lymphoblastic lymphomas, more frequently involve the serous fluids. The thoracic duct obstruction and impaired lymphatic drainage appear to be the primary mechanism for pathogenesis of pleural effusion in HD and direct pleural infiltration is the predominant cause in NHL. There is wide variation in rate of positive cytologic findings of NHL in pleural effusion (22.2-94.1%). Cytologic features of specific lymphoma subtypes such as lymphoblastic lymphoma, follicular center cell lymphoma, including Burkitt-type lymphoma, marginal zone lymphoma, MALT lymphoma, and anaplastic large-cell lymphoma, etc., have been described in the literature. The differential diagnostic problems of lymphomas in serous effusions include reactive lymphocytoses, early involvement by lymphomatous process, small round-cell tumors (SRCT), and presence of look-alike of Reed-Sternberg cells. To overcome these difficulties, various ancillary studies, including immunocytochemistry (ICC), morphometry, flow cytometry (FCM), and cytogenetics/molecular genetics (PCR, in-situ hybridization, and Southern blotting), have been performed on effusion specimens. ICC not only distinguishes lymphomas from reactive lymphocytoses and SRCTs, it significantly modifies the morphologic diagnosis to achieve a better classification of lymphomas. Combined morphology and immunophenotyping by FCM, has a sensitivity as well as specificity of 100%. Morphometry also distinguishes reactive lymphocytoses from malignant lymphoma with a high degree of sensitivity (>85%) and specificity (>95%). Limitations of individual ancillary techniques can be overcome by using multiple parameters. Although lymphomas rarely present as serous effusions without the involvement of other thoracic and extrathoracic sites, a small group of lymphomas called primary effusion lymphomas (PEL) exhibit exclusive or dominant involvement of serous cavities, without a detectable solid tumor mass. This body cavity based lymphoma (BCBL) is a distinct clinicopathologic entity and is found predominantly in AIDS patients with preexisting Kaposi sarcoma. In the absence of obstructive or infiltrative tumor mass, its pathogenesis has been attributed to stimulation by vascular endothelial growth factor (VEGF)/vascular permeability factor (VPF), leading to vascular leakage. Cytomorphologically, PEL is usually a large-cell lymphoma, which appears to bridge features of large-cell immunoblastic and anaplastic large-cell lymphoma (ALCL). Most of these cases comprise a unique subgroup of B-cell lymphoma, with features of both high-grade anaplastic and B-immunoblastic lymphoma, but T-cell and/or natural killer cell immunophenotypes are described. Its association with various viral DNAs has been studied in detail by molecular techniques. Pleural effusion due to lymphomas, either primary or otherwise, is considered as one of the factors adversely influencing overall survival. The presence of pleural effusion at the time of presentation is not only associated with extremely poor outcome of lymphomas, it is also a predictor of disease relapse after chemotherapy and decreased survival. When the patients of lymphomatous pleural effusions with and without mediastinal mass present in respiratory distress, thoracocentesis is the initial diagnostic and therapeutic choice in these patients. In such situations, cytology along with ancillary studies not only gives a quick diagnosis of lymphoma, but also offers prognostically significant information such as classification of lymphomas, its grade and immunophenotype, and presence/absence of viral DNAs and tumor lysis syndrome.

CD5+ diffuse large B-cell lymphoma with c-myc/IgH rearrangement presenting as primary effusion lymphoma

We report an instructive case of diffuse large B-cell lymphoma presenting as acute heart failure. A 69-year-old human immunodeficiency virus-negative man was admitted to our hospital for general fatigue. A computed tomographic scan of the chest and abdomen showed pericardial effusion, but there was no evidence of tumor masses, lymph node enlargement, or hepatosplenomegaly. During the chemotherapy, increased lactate dehydrogenase and pleural effusion appeared. The tumor cells in the effusion showed positivity for CD5, CD19, CD20, kappa chain, and Bcl-2 and negativity for CD10 and CD23. The chromosomes showed t(8;14)(q24;q32) with c-myc/immunoglobulin (Ig)H rearrangement, and the MIB-1 index was not high (60%). Neither human herpes virus 8 nor Epstein-Barr virus DNA was detected in the cells by polymerase chain reaction. The response to chemotherapy was very poor, and the patient died 4 months after the diagnosis. A spectrum of the symptoms of CD5+ lymphoma encompasses pericardial effusion and also can accompany c-myc/IgH rearrangement.

Primary effusion lymphoma of the pericardial cavity carrying t(1;22)(q21;q11) and t(14;17)(q32;q23)

We report a case of primary effusion lymphoma (PEL) in a 75-year-old woman without human immunodeficiency virus or hepatitis C virus, which presented as fever, chest pain, and pericardial effusion. The lymphoma cells were positive for CD20 and CD79a, and were negative for CD3 and CD10. Genomic human herpes virus 8 (HHV-8) and Epstein-Barr virus were not detected in the lymphoma cells. Cytogenetic analysis showed complex abnormalities by the G-banding technique, and spectral karyotyping (SKY) analysis provided more detailed characterization of the chromosomal aberrations, including t(1;22)(q21;q11) and t(14;17)(q32;q23). We did not detect C-MYC gene rearrangement or BCL-2 expression. She was treated successfully with six courses of the CHOP regimen. The present case demonstrated a rare category of PEL that is not associated with HHV-8 or C-MYC gene rearrangement. In addition, SKY analysis disclosed cryptic chromosomal abnormalities involving 1q21 and 17q23.

An unusual case of posttransplant peritoneal primary effusion lymphoma with T-cell phenotype in a HIV-negative female, not associated with HHV-8

Primary effusion lymphoma (PEL) is a recently individualized form of non-Hodgkin's lymphoma (WHO classification) that mainly develops in HIV infected males, more frequently in homosexuals and advanced stages of the disease (total CD4+ lymphocyte count below 100-200/microL). Occasionally, it appears in other immunodepressive states (such as solid organs transplant period) and even, although very rarely, in immunocompetent patients. From a pathogenetic point of view, PEL has been related to Kaposi's sarcoma associated herpes virus (also named human herpesvirus 8, HHV-8), an etiological factor of Kaposi's sarcoma. The relative infrequency of this disease, the absence of wide casuistics allowing a better characterization, and its unfavorable outcome support the need of a deeper knowledge. We present here the clinical-biological findings of a patient, HIV seronegative, who was diagnosed with peritoneal PEL of T-cell origin, and not HHV-8-associated, five years after renal transplantation.

Durable Remission by Sobuzoxane in an HIV-Seronegative Patient with Human Herpesvirus 8-Negative Primary Effusion Lymphoma

Primary effusion lymphoma (PEL) is recognized as a unique clinicopathological entity associated with human herpesvirus 8 (HHV-8), and it occurs almost exclusively in human immunodeficiency virus (HIV)-infected individuals. In the majority of PEL cases, Epstein-Barr virus (EBV) has been found in the tumor cells as well. We describe here an elderly HIV seronegative female patient with PEL in the pleura and pericardium not associated with HHV-8 or EBV. Cytologic examinations of the pleural effusion revealed large lymphoma cells with immunophenotypes positive for CD8, CD10, CD19, CD20, CD22, CD24, CD45, and HLA-DR but negative for CD30 and surface immunoglobulin. Chromosome analysis showed complicated abnormalities including add(3)(q27). Immunoglobulin gene rearrangement was detected by Southern blotting; however, c-myc, Bcl-2, and Bcl-6 genes were not rearranged. The patient was treated with a modified CHOP (cyclophosphamide, hydroxydoxorubicin, oncovine, and prednisolone) regimen, and achieved remission. Recurrence of PEL in the pericardium as effusion lymphoma was found 3 months after the discontinuation of CHOP. After approximately 1 year of intermittent multiagent salvage therapy for pericardial recurrences, a treatment that resulted in a partial response, 3 cycles of monotherapy with sobuzoxane were administered. At the time of this report the patient had been free from PEL for more than 18 months without chemotherapy.

Human herpes virus-8-negative primary effusion lymphoma in a patient with common variable immunodeficiency

Primary effusion lymphoma (PEL) is a newly described high-grade B cell lymphoma developing in association with human herpes virus type 8 (HHV-8) in human immunodeficiency virus (HIV)-infecting individuals. Common variable immunodeficiency (CVID) is a primary immunodeficiency disease characterized by reduced serum immunoglobulin and heterogeneous clinical features. The risk of cancer in CVID patients is increased. Here, we describe a PEL that developed in the pleural and pericardial cavities of an HIV-negative and HHV-8-negative patient with CVID.

Human herpes virus 8-negative primary effusion lymphoma (PEL) in a patient after repeated chylous ascites and chylothorax

We describe a case of malignant lymphoma which presented in the body cavities without identifiable tumor masses. Malignant lymphoma cells showed strong atypia with prominent nuclei and basophilic cytoplasm containing vacuoles. The chromosomes showed diploidy and complex abnormalities including translocations and deletions. We diagnosed this patient with primary effusion lymphoma (PEL), even though she tested negative for human herpes virus-8 (HHV-8) which has been suggested to be causally related to PEL. Interestingly, the patient also showed complicated protein-losing enteropathy, and PEL occurred after repeated chylous ascites and chylothorax. The possible pathogenesis of this rare disease is discussed here.

An unusual case of primary effusion lymphoma in a HIV-negative patient not pathogenetically associated with HHV8

The development of an unusual case of primary pleural effusion in a 90-year-old human immunodeficiency virus (HIV)-negative Japanese woman with no identifiable tumor mass has been described. Pleural effusion specimens contained large diffuse lymphoma cells, with the phenotype and genotype of a B-cell lineage (positive for CD20, CD79a and clonal rearrangement of Ig heavy chain) and the c-myc gene rearrangement, but were negative for T-cell markers (CD45RO and CD3). The patient was negative for human herpes virus 8 (HHV8), Epstein-Barr virus (EBV) and hepatitis C virus (HCV), as well as human T-cell lymphotropic virus type-1 (HTLV-1). The patient died of respiratory failure 5 months after the diagnosis of primary effusion lymphoma (PEL), and an autopsy was performed. Autopsy findings revealed no evidence of tumor mass or bone marrow involvement of lymphoma cells. This case has been considered as a PEL in a HIV-, HHV8-, EBV- and HCV-negative patient. Although cytomorphology of lymphoma cells was classified as large-cell lymphoma in this case, it is interesting that the present case may represent an unusual subset of Burkitt-like disease because of clear B-cell phenotype and c-myc gene rearrangement.

Natural killer cell-type body cavity lymphoma following chronic active Epstein-Barr virus infection

We describe a 69-year-old female who developed natural killer cell-type body cavity lymphoma following chronic active Epstein-Barr virus (CAEBV) infection. Examination of the patient's pleural effusion revealed large abnormal lymphocytes, which were CD2(+), CD7(+), CD30(+), CD56(+), CD3(-), and CD4(-). No rearrangement of T cell receptor genes was detected. Clonal proliferation of Epstein-Barr virus (EBV)-infected cells in pleural effusion was demonstrated by Southern blot hybridization analysis. Human herpesvirus type-8 (HHV-8) DNA was not detected in these cells. The patient achieved a complete remission with combination chemotherapy. Prior to the clinical onset of lymphoma, high fever of unknown origin had persisted for 21 months. IgG antibodies to EBV-viral capsid antigen and to EBV-early antigens, types D and R were not high (1:160 and less than 1:10, respectively). Two months after the onset of fever, however, retrospective quantitative PCR assay revealed a high EBV DNA load in plasma, indicating that CAEBV infection had been the cause of the patient's recurrent fever. The remarkable features of this case are (i) the development of lymphoma following CAEBV infection that demonstrated a normal pattern of EBV-specific antibodies, (ii) the development of HHV-8-negative body cavity lymphoma, and (iii) the effectiveness of combination chemotherapy.