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

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.

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.

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.

Indolent primary effusion lymphoma-like lymphoma in the pericardium: A case report and review of the literature

We report a rare case of a 75-year-old man with a history of mild-to-moderate pericardial effusion that was detected on echocardiography performed in October 2011 when the patient was 69 years old. Follow-up echocardiography was performed every 6 months thereafter, showing that the pericardial effusion gradually subsided. However, in April 2017 he started experiencing several episodes of dyspnea, which prompted him to visit our hospital's outpatient department on June 22, 2017. Echocardiography revealed a large amount of pericardial effusion; thus, he was immediately hospitalized. After undergoing pericardiocentesis and drainage, 1740-ml of bloody pericardial fluid was collected. Serum antibody tests for human immunodeficiency virus, hepatitis C virus, and human herpes virus 8 were negative, whereas that for Epstein-Barr virus (EBV) was positive, indicating a prior infection. Cytopathological examination, immunocytochemical staining, lymphocyte surface marker analysis, and cytogenetic assessment were performed. EBV-encoded small ribonucleic acid in situ hybridization was negative. He was diagnosed with primary effusion lymphoma (PEL)-like lymphoma (LL) and was treated with 8 doses of rituximab 375 mg/m² over a 2-month period. He has remained in complete response for the past 12 months. Our case shows the possibility of long-term existence of indolent PEL-LL in patients with mild-to-moderate pericardial effusion. <Learning objective: Primary effusion lymphoma (PEL)-like lymphoma (LL) is a rare disease with a poorly understood pathophysiology. Some patients are able to achieve a complete response after drainage of the effusion without chemotherapy. We experienced a case of PEL-LL, which was only diagnosed after 6 years of continually observing the pericardial effusion. Cardiologists should consider PEL-LL as a differential diagnosis in patients with unexplained pericardial effusion.>.

A Case of Diffuse Large B-Cell Lymphoma Mimicking Primary Effusion Lymphoma-Like Lymphoma

A 93-year-old female was transferred to the emergency ward of our hospital due to disturbance of consciousness and hypotension. Computed tomography showed bilateral pleural and pericardial effusion without evidence of tumor masses or lymphadenopathy. Cytodiagnosis of pleural effusion revealed proliferation of atypical lymphoid-like cells with pan-B surface markers. We suspected primary effusion lymphoma-like lymphoma; however, the monoclonality of these cells was not confirmed. Cytodiagnosis of bone marrow revealed lymphoma cells with monoclonal B-cell markers. These findings prompted a diagnosis of diffuse large B-cell lymphoma with bone marrow invasion. In the case of pericardial or pleural effusion, clinicians should consider carefully both hematological malignancy and its classification.

Human herpes virus 8-unrelated primary effusion lymphoma-like lymphoma in the pericardium: A case with latency type III Epstein-Barr virus infection showing good prognosis without chemotherapy

Primary effusion lymphoma (PEL) is a rare subtype of non-Hodgkin lymphoma that proliferates in body cavities without detectable masses. PEL is universally associated with human herpes virus-8 (HHV-8) infection and has an aggressive prognosis. Recently, an HHV-8-unrelated PEL-like lymphoma that usually occurs in elderly individuals and follows a more indolent prognosis has been reported, and it is treated as a disease distinct from PEL. However, its pathogenesis and prognostic factors have not been sufficiently clarified. In PEL-like lymphoma accompanied by Epstein-Barr virus (EBV) infection, latent infection types are not mentioned in the literature. Herein, we report the case of an 85-year-old Japanese man with pericardial PEL-like lymphoma who showed good improvement in condition for 24 months after pericardiocentesis without chemotherapy. Serological test results were positive for EBV capsid antigen and EBV nuclear antigen 2 (EBNA2), but negative for human immunodeficiency virus, hepatitis B virus, and hepatitis C virus. The disease phenotype and EBV infection mechanism were immunohistochemically investigated by the cellblock prepared from pericardial effusion. Atypical cells were positive for CD20, CD30, CD45, BCL2, MUM1, EBNA2, latent membrane protein 1, and EBV-encoded RNA (on in situ hybridization), but negative for CD3, CD5, CD10, CD138, cytokeratin AE1/AE3, and HHV-8. Accordingly, this case was considered to be a B-cell activated phenotype with a type III latent EBV infection. Type III latent EBV infection is unusual in PEL.

HHV8-negative effusion based lymphoma: a series of 17 cases at a single institution

INTRODUCTION

Human herpesvirus 8-positive (HHV8+) primary effusion lymphoma is a well-recognized clinicopathologic entity. In contrast, HHV8-negative (HHV8-) effusion-based lymphoma (EBL) is incompletely characterized and under-recognized. We describe 17 cases of HHV8- EBL at our institution.

MATERIALS AND METHODS

Cytology and available immunohistochemistry and cytogenetics were reviewed. Patient demographics, history, and outcome were obtained from medical records.

RESULTS

The effusions were pleural (n = 9; 53%), peritoneal (n = 4; 24%), pericardial (n = 3; 18%), and pleural and pericardial (n = 1; 6%). Fifteen cases (88%) were CD20+ and 15 had sufficient information for classification by Hans algorithm (CD10, BCL6, MUM1): 11 (73%) nongerminal center and 4 (27%) germinal center phenotype. Epstein-Barr virus in situ hybridization was negative in 16 cases (94%). Three of 14 cases were MYC+ by immunohistochemistry. Fluorescence in situ hybridization, performed on 5 of the 17 cases, showed a MYC rearrangement in 1 case and a BCL6 rearrangement in 2 cases. Most patients were elderly (median age 86 years) and female (82%). Human immunodeficiency virus testing results, available in 4 patients, were negative. Seven (41%), including 1 of 2 heart transplant recipients, had congestive heart failure. Follow-up (5 days to 12 years) was available for 16 patients including 4 who survived ≥8 years. Only 1 of the 8 known deaths was clinically attributed to lymphoma.

CONCLUSIONS

HHV8- lymphomas that occur in body cavity effusions without detectable lymphomatous masses are usually composed of large CD20+ lymphoid or lymphoplasmacytoid cells. In contrast to HHV8+ primary effusion lymphoma, patients with HHV8- EBL are usually elderly, lack a documented human immunodeficiency virus-positive history, and have a longer disease specific survival.

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.

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.

Primary pleural neoplasia: entities other than diffuse malignant mesothelioma

CONTEXT

Overwhelmingly, the most common neoplasm involving the pleura is metastatic carcinoma. In contrast, diffuse malignant mesothelioma occurs relatively rarely; however, it is nonetheless the most common neoplasm primary to the pleura. Metastatic carcinoma and diffuse malignant mesothelioma each have their own prognostic and therapeutic characteristics. Other primary pleural neoplasms occur uncommonly or rarely, with their own prognostic and therapeutic characteristics.

OBJECTIVE

To review primary pleural neoplasms other than diffuse malignant mesothelioma, to better ensure correct diagnosis and optimal assessment of prognosis and treatment.

DATA SOURCES

Literature review and primary material from the authors' institutions.

CONCLUSIONS

A nonexhaustive group of uncommon to rare benign and malignant primary pleural neoplasms--other than diffuse malignant mesothelioma--are presented, of which one must be aware in order to maintain an appropriate index of suspicion to include them in the differential diagnosis of a pleural tumor.

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.

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.

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.

Lyme borreliosis and multiple sclerosis are associated with primary effusion lymphoma

Multiple sclerosis (MS) is a chronic disease of the central nervous system characterized by chronic inflammation and demyelination. Studies suggested that the viral, especially Epstein-Barr virus infection, and bacterial infections, especially Borrelia burgdorferi infection, play a role in etiology of MS. MS prevalence parallels the distribution of the Lyme disease pathogen B. burgdorferi. Criteria used for diagnosis of MS can also be fulfilled in other conditions such as Lyme disease, a multisystem disorder resulting from infection by the tick-borne spirochete, B. burgdorferi. In the late period of Lyme disease demyelinating involvement of central nervous system can develop and MS can be erroneously diagnosed. A Lyme borreliosis can mimick central nervous system lymphoma. Also, B. burgdorferi has been implicated not only in etiology of MS, but also in etiology of lymphoma. Studies suggested that there is an increased risk of non-Hodgkin lymphoma in patients, who had a history of autoimmune diseases such as MS and that both non-Hodgkin's lymphomas and Hodgkin's disease were associated with Epstein-Barr virus infection. A small group of lymphomas called primary effusion lymphomas (PEL) is a recently individualized form of non-Hodgkin's lymphoma (WHO classification) that exhibit exclusive or dominant involvement of serous cavities, without a detectable solid tumor mass. These lymphomas have also been linked to Epstein-Barr virus and human herpes virus type 8 infections but virus negative cases have been described. Therefore, we propose that MS and neuroborreliosis are linked to central nervous system primary effusion lymphomas. As a first step in confirming or refuting our hypotheses, we suggest a thorough study of CSF in the patients suspected for the diagnosis of MS and Lyme borreliosis.

Primary effusion lymphoma with skin involvement

Primary effusion lymphoma (PEL) was once defined as a body cavity-based lymphoma without identifiable contiguous tumour mass, but is now recognised as an independent clinicopathological entity. The case of a 67-year-old Japanese woman with PEL is reported, in which the clinical findings showed a pericardial effusion and multiple erythema on the hypogastrium and inguinal region. The histopathological findings showed a diffuse infiltration of large neoplastic B cells from the dermis to the subcutis. After the disappearance of pericardial effusion without any treatment, she received several rounds of chemotherapy to resolve the skin eruption, but she finally died from multiple organ failure. No tumour mass was observed during the course of her disease.

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.

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.

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.

Epstein–Barr virus myocarditis as a cause of sudden death: two autopsy cases

Although the Epstein-Barr virus (EBV) causes acute infection accompanied by a high fever in young people, there appears to be few reports of a fatal outcome involving myocarditis. We report two cases of unexpected sudden death due to acute myocarditis possibly caused by the EBV. They each visited a hospital due to common cold-like symptoms and unexpectedly died several days later. In both cases, autopsy revealed myocardial necrosis with marked lymphocytic infiltration. Polymerase chain reaction (PCR) screening was positive for the EBV, whereas immunohistochemistry and in situ hybridization for the EBV were negative. Serological investigations showed a mild elevation in antiviral capsid antigen IgG and anti-EBV nuclear antigen IgG in both cases. Immunohistochemical study of lymphocytic infiltrates showed strong positivity for a T-cell marker (CD45R0) in the myocardium and pharyngeal mucosa. These cases suggest the potential risk of mortality from acute EBV infection in young people, even without severe clinical manifestations, and the importance of microbiological investigations, including PCR procedures, in postmortem diagnosis of infectious diseases.

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.