Pyothorax-associated lymphoma: a lymphoma developing in chronic inflammation

Breast implant associated EBV-positive Diffuse Large B-cell lymphoma: an underrecognized entity?

Breast-implant associated (BIA) lymphoma is an infrequent type of cancer occurring in the fluid and fibrous capsule around a textured breast implant. Recently, both the 2022 WHO 5th edition classification of Haematological tumours (WHO HAEM5) and 2022 International Consensus Classification of Mature Lymphoid Neoplasms (22ICC), recognized breast implant-associated Anaplastic Large Cell Lymphoma (BIA-ALCL) as a definitive entity, defined as a mature CD30-positive T-cell lymphoma, confined by a fibrous capsule, in a breast implant setting. Only few B-cell lymphomas have been reported in the literature to be associated with breast implants. Here we report two EBV-positive Diffuse Large B-cell lymphomas (EBV + DLBCL) in relation to a breast implant, both expressing CD30 as well as EBV latency type 3. Both lesions were considered as DLBCL associated with chronic inflammation (CI-DLBCL), but one presented as a 7 cm solid mass, while the other presented as a fibrin-associated DLBCL (FA-DLBCL) in an HIV patient. Clinically, both are in complete remission 6 months or longer after capsulectomy and graft removal, without additional chemotherapy.Such cases, characterized by large CD30-positive cells, can easily be misdiagnosed as BIA-ALCL if the cell of origin is not further established. Therefore, a diagnostic panel including lineage-specific B-and T-cell markers and EBER in situ hybridization is essential to recognize this rare entity, to understand lymphomagenesis, to predict outcome and to define clinical approach.

Large B-Cell Lymphomas in the 5th Edition of the WHO-Classification of Haematolymphoid Neoplasms-Updated Classification and New Concepts

The family/class of the large B-cell lymphomas (LBCL) in the 5th edition of the World Health Organization (WHO) classification of haematolymphoid tumors (WHO-HAEM5) features only a few major changes as compared to the 4th edition. In most entities, there are only subtle changes, many of them only representing some minor modifications in diagnostic terms. Major changes have been made in the diffuse large B-cell lymphomas (DLBCL)/high-grade B-cell lymphomas (HGBL) associated with MYC and BCL2 and/or BCL6 rearrangements. This category now consists of MYC and BCL2 rearranged cases exclusively, while the MYC/BCL6 double hit lymphomas now constitute genetic subtypes of DLBCL, not otherwise specified (NOS) or of HGBL, NOS. Other major changes are the conceptual merger of lymphomas arising in immune-privileged sites and the description of LBCL arising in the setting of immune dysregulation/deficiency. In addition, novel findings concerning underlying biological mechanisms in the pathogenesis of the different entities are provided.

EBV-positive pyothorax-associated lymphoma expresses CXCL9 and CXCL10 chemokines that attract cytotoxic lymphocytes via CXCR3

Epstein-Barr virus (EBV)-positive diffuse large B-cell lymphoma associated with chronic inflammation (DLBCL-CI) develops in the setting of long-standing inflammation. This type of lymphoma may have specific expression profiles of chemokines involved in the pathogenesis of DLBCL-CI. EBV-positive pyothorax-associated lymphoma (PAL) is a prototype of DLBCL-CI and represents a valuable model for the study of this disease category. Using a panel of PAL cell lines, we found that PAL cells expressed and secreted C-X-C motif chemokine ligands 9 and 10 (CXCL9 and CXCL10), the ligands of CXCR3, in contrast to EBV-negative DLBCL cell lines, which did not. Culture supernatants from PAL cell lines attracted CXCR3-expressing CD4⁺ T cells, CD8⁺ T cells, and CD56⁺ natural killer cells from human peripheral blood mononuclear cells. PAL cells injected into mice also attracted CXCR3-positive cytotoxic lymphocytes that expressed interferon-γ. The expression of CXCL9 and CXCL10 was detected in PAL tumor biopsy samples from patients, and CXCR3-positive lymphocytes were abundant in the tissue samples. Collectively, these findings suggest that CXCL9 and CXCL10 are produced by PAL cells and can elicit cytotoxic responses via CXCR3. This chemokine system is also likely to contribute to tissue necrosis, which is a signature histological feature of DLBCL-CI. Further studies are warranted to determine whether the CXCL9-CXCL10/CXCR3 axis exerts antitumor effects in DLBCL-CI.

Integration of Human and Viral miRNAs in Epstein-Barr Virus-Associated Tumors and Implications for Drug Repurposing

Epstein-Barr virus (EBV) is associated with several tumors, and has substantial relevance for public health. Therapeutics innovation for EBV-related disorders is much needed. In this context, miRNAs are noncoding RNA molecules that play vital roles in EBV infection. miRNA-Seq and RNA-Seq data for EBV-associated clinical samples and cell lines have been generated, but their detailed integrative analyses, and exploitation for drug repurposing against EBV are lacking. Hence, we identified and analyzed the differentially expressed miRNAs (DEmiRs) in EBV-infected cell lines (28) and infected (28) and uninfected human tissue (20) samples using an in-house pipeline. We found significantly enriched host miRNAs like hsa-mir-3651, hsa-mir-1248, and hsa-mir-29c-3p in EBV-infected samples from EBV-associated nasopharyngeal carcinoma and Hodgkin's lymphoma, among others. Furthermore, we also identified significantly enriched novel miRNAs such as hsa-mir-29c-3p, hsa-mir-3651, and hsa-mir-98-3p, which were not previously reported in EBV-related tumors. Differentially expressed mRNAs (DEMs) were identified in EBV-infected cell lines (21) and uninfected human tissue (14) samples. We predicted and selected 1572 DEMs (upregulated) that are targeted by 547 DEmiRs (downregulated). These were further classified into essential (870) and nonessential (702) genes. Moreover, a miRNA-mRNA network was developed for the hub miRNAs. Importantly, we used the DEMs during EBV latent infection types I, II, and III to identify the candidate drugs for repurposing: Glyburide, Levodopa, Nateglinide, and Stiripentol, among others. To the best of our knowledge, this is the first integrative analyses that identified DEmiRs and DEMs as potential therapeutic targets and predicted drugs as potential candidates for repurposing against EBV-related tumors.

Breast implant-associated EBV-positive diffuse large B-cell lymphoma: Two case reports and literature review

Lymphomas associated with breast implants are mostly of the T-cell type. They are predominantly anaplastic lymphoma kinase-negative anaplastic large cell lymphoma (ALK-negative ALCL) characterized by CD30 positivity universally. Whilst the majority of primary breast lymphomas occurring in the absence of breast implants are of B-cell origin, there are few cases of implant-associated B-cell lymphomas reported to date in the literature, a subset of which are diffuse large B-cell lymphoma (DLBCL). Given the rarity of this entity, we describe two cases of breast implant-associated DLBCL. Both patients developed Epstein-Barr Virus (EBV)-positive large cell lymphoma of B-cell origin confined to the implant capsule with no evidence of systemic lymphoma. Considering the association with EBV, the activated B-cell phenotype and the presumed chronic inflammatory environment associated with the implant capsule, these might represent forms of DLBCL associated with chronic inflammation (DLBCL-CI) or fibrin-associated DLBCL (FA-DLBCL). Treatment included implant removal with total capsulectomy, and for one of the cases adjuvant systemic chemotherapy. Recognizing this rare type of breast implant-associated B-cell lymphoma could improve our understanding of this entity and hence develop appropriate management strategies.

A case of diffuse large B-cell lymphoma originating from chest wall complicated by benign asbestos pleural effusion

A 78-year-old man with exposure to asbestos was admitted to our hospital for back pain. A chest computed tomography showed right pleural effusion and a significant increase in the size of masses in the right chest wall over an interval of six months. He did not undergo further examinations and expired one month later. Autopsy revealed the presence of diffuse large B-cell lymphoma (DLBCL) and complicated by benign asbestos pleural effusion. We considered that this tumour had originated from the soft tissue in the chest wall based on the radiological and autopsy findings. The present report highlights that primary DLBCL of chest wall might be associated with chronic inflammation due to asbestos-related pleural diseases.

Characterization of Artificial Pneumothorax-Unrelated Pyothorax-Associated Lymphoma

Pyothorax-associated lymphoma (PAL) is a rare disease developing from a long-term pleural cavity inflammation. Most reported PAL cases have a history of artificial pneumothorax. However, the clinical features of artificial pneumothorax-unrelated PAL remain largely unknown. Here, we reported two PAL cases diagnosed from our center in the past ten years. One case developed from asymptomatic pyothorax after pneumonectomy with a latency of 28 years, while the other case showed a relatively short latency of one year. Then we reviewed the literature of artificial pneumothorax-unrelated PAL by searching PubMed and Google Scholar from 2007. In total, nine artificial pneumothorax-unrelated PAL cases were found, predominantly in old male with median age of 76 years (ranging from 51 to 88). Most cases were diagnosed with diffuse large B-cell lymphoma (DLBCL) (n = 8, 88.9%) and had evidence of Epstein-Barr virus (EBV) infection (n = 6, 66.7%) or tuberculous pleurisy (n = 5, 55.6%). Notably, four cases (44.4%) had short intervals (no more than two years) between pleuritis and PAL. Regarding the overall survival, one-third cases survived more than 5 years after the diagnosis of PAL. In conclusion, the features of artificial pneumothorax-unrelated PAL are comparable with the classic type of PAL, except for some patients with short duration of pleuritis, and need to be identified. Treatment guideline of DLBCL is recommended for the management of PAL.

Diffuse large B-cell lymphoma variants: an update

Diffuse large B-cell lymphoma (DLBCL) is the most common type of lymphoma, representing approximately one-third of all cases worldwide. In the World Health Organization (WHO) classification of lymphomas, most cases of DLBCL are designated as not otherwise specified (NOS). About 20% of cases, however, are designated as specific variants of DLBCL. These variants, 13 in total, are specified on the basis of distinctive morphological or immunophenotypic findings or distinctive biological or clinical issues associated with their diagnoses. In this review we discuss the following variants: T-cell/histiocyte-rich large B-cell lymphoma; ALK-positive large B-cell lymphoma; plasmablastic lymphoma; intravascular large B-cell lymphoma; large B-cell lymphoma with IRF4 rearrangement; primary mediastinal large B-cell lymphoma; primary cutaneous diffuse large B-cell lymphoma, leg type; primary diffuse large B-cell lymphoma of the central nervous system; diffuse large B-cell lymphoma associated with chronic inflammation; lymphomatoid granulomatosis; primary effusion lymphoma; and HHV8-positive diffuse large B-cell lymphoma, NOS. Two additional variants recognised in the WHO classification, EBV-positive diffuse large B-cell lymphoma and EBV-positive mucocutaneous ulcer are discussed elsewhere in another review within this issue of Pathology. Although not recognised as a specific variant in the current WHO classification, primary testicular diffuse large B-cell lymphoma also has unique biological features and requires some modification of the standard treatment approach for patients with DLBCL. Therefore, we suggest that primary testicular diffuse large B-cell lymphoma also should be recognised as a specific variant of DLBCL in a future version of the WHO classification.

Diagnostic Performance of ¹⁸F-Fluorodeoxyglucose Positron Emission Tomography/CT for Chronic Empyema-Associated Malignancy

OBJECTIVE

The purpose of this study was to evaluate the diagnostic performance of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) for chronic empyema-associated malignancy (CEAM).

MATERIALS AND METHODS

We retrospectively reviewed the ¹⁸F-FDG PET/CT images of 33 patients with chronic empyema, and analyzed the following findings: 1) shape of the empyema cavity, 2) presence of fistula, 3) maximum standardized uptake value (SUV) of the empyema cavity, 4) uptake pattern of the empyema cavity, 5) presence of a protruding soft tissue mass within the empyema cavity, and 6) involvement of adjacent structures. Final diagnosis was determined based on histopathology or clinical follow-up for at least 6 months. The abovementioned findings were compared between the ¹⁸F-FDG PET/CT images of CEAM and chronic empyema. A receiver operating characteristic (ROC) analysis was also performed.

RESULTS

Six lesions were histopathologically proven as malignant; there were three cases of diffuse large B-cell lymphoma, two of squamous cell carcinoma, and one of poorly differentiated carcinoma. Maximum SUV within the empyema cavity (p < 0.001) presence of a protruding soft tissue mass (p = 0.002), and involvement of the adjacent structures (p < 0.001) were significantly different between the CEAM and chronic empyema images. The maximum SUV exhibited the highest diagnostic performance, with the highest specificity (96.3%, 26/27), positive predictive value (85.7%, 6/7), and accuracy (97.0%, 32/33) among all criteria. On ROC analysis, the area under the curve of maximum SUV was 0.994.

CONCLUSION

¹⁸F-FDG PET/CT can be useful for diagnosing CEAM in patients with chronic empyema. The maximum SUV within the empyema cavity is the most accurate ¹⁸F-FDG PET/CT diagnostic criterion for CEAM.

Primary Chest Wall MYC/BCL6 Double-hit Lymphoma with t (3;7) (q27;p12) and t (8;14) (q24;q32) Translocations

Primary chest wall lymphoma is rare and typically associated with chronic pleural inflammation. Double-hit lymphoma (DHL), which is defined as aggressive mature B-cell lymphoma with MYC and BCL2 or BCL6 rearrangements, is a highly aggressive malignancy that tends to have extranodal involvement and is resistant to standard immunochemotherapy. We herein report a 55-year-old man with no history of chronic pleural inflammation, diagnosed with primary chest wall DHL with MYC/BCL6 rearrangement, and harboring a unique BCL6 translocation, t (3;7) (q27;p12). After six courses of intensive chemotherapy, he has achieved complete remission. To our knowledge, this is the first case report of primary chest wall DHL.

Prognostic Value of Accumulative Expression of COX-2 and p53 in Small and Diffuse Large B Cell Lymphoma

Cyclooxygenase-2 (COX-2) plays an important role in carcinogenesis, which catalyzes the conversion of arachidonic acid into prostaglandins. P53 is a tumor suppressor gene that contributes to apoptosis and cell cycle control. There is functional interaction between p53 and COX-2, which lead to abrogation of apoptosis and progression of malignancy. To assess the relationship between COX-2, p53 expression and the clinicopathololgic features in SLL and DLBCL. We immunohistochemically examined the expression of COX-2 and p53 in non-neoplastic lymphoid cells, lymph nodal low-grade (50 cases of SLL), intermediate and high-grade lymphomas (100 cases of DLBCL) and their corresponding bone marrow specimens. The expression of COX-2 and p53 was absent in the in non-neoplastic lymphoid cells. In contrast, their expression values increased progressively with the advancing grade of lymphoma (p < 0.001). COX-2 expression was significantly associated with advanced disease stage, high-grade lymphomas, and disease relapse and p53 expression. The p53was detected in 64.5% in patients positive for COX-2. The expressions of COX-2 and p53 proteins, were significantly associated with shorter overall-survival and progression free survival. Here we report up-regulation of COX-2and p53 protein expression in SLL and DLBCL indicating their interactive involvement in the pathogenesis of lymphoma. Our data provide a rationale for further investigation of COX-2 expression in lymphomas for potential prognostic, chemopreventive and chemotherapeutic purposes.

Human Immunodeficiency Virus-Associated Lymphoproliferative Disorders

HIV infection is associated with an increased risk for developing B-cell lymphoproliferative disorders. The spectrum of disease differs in HIV-infected versus HIV-uninfected persons, with aggressive B-cell non-Hodgkin lymphomas constituting a higher proportion of all lymphoproliferative disorders in the HIV-positive population. Although antiretroviral therapy (ART) has significantly changed the landscape of lymphomas arising in HIV-infected persons, population growth and aging are reflected in the steady increase in non-AIDS-defining cancers. In the ART era, outcomes for HIV-infected lymphoma patients are similar to those of HIV-negative patients. This article reviews the diagnostic features and summarizes current biologic understanding of HIV-associated lymphomas.

MR Imaging of Pleural Neoplasms

The pleura may be affected by primary tumors or metastatic spread of intrathoracic or extrathoracic neoplasms. Primary pleural neoplasms represent ∼10% of all pleural tumors, and malignant lesions are more common than benign lesions. The most common primary tumors include malignant pleural mesothelioma and solitary fibrous tumor. Although pleural neoplasms may initially be evaluated with computed tomography (CT) and/or fluorodeoxyglucose positron emission tomography (PET)/CT, magnetic resonance (MR) imaging is complementary to these other imaging modalities for disease staging and evaluation of patients. In this article, we discuss the etiology, clinical presentation, and imaging of pleural neoplasms, with specific attention given to the role of MR imaging.

EBV-Positive Lymphoproliferations of B- T- and NK-Cell Derivation in Non-Immunocompromised Hosts

The contribution of Epstein-Barr virus (EBV) to the development of specific types of benign lymphoproliferations and malignant lymphomas has been extensively studied since the discovery of the virus over the last 50 years. The importance and better understanding of the EBV-associated lymphoproliferative disorders (LPD) of B, T or natural killer (NK) cell type has resulted in the recognition of new entities like EBV+ mucocutaneous ulcer or the addition of chronic active EBV (CAEBV) infection in the revised 2016 World Health Organization (WHO) lymphoma classification. In this article, we review the definitions, morphology, pathogenesis, and evolving concepts of the various EBV-associated disorders including EBV+ diffuse large B-cell lymphoma, not otherwise specified (DLBCL, NOS), EBV+ mucocutaneous ulcer, DLBCL associated with chronic inflammation, fibrin-associated DLBCL, lymphomatoid granulomatosis, the EBV+ T and NK-cell LPD of childhood, aggressive NK leukaemia, extranodal NK/T-cell lymphoma, nasal type, and the new provisional entity of primary EBV+ nodal T- or NK-cell lymphoma. The current knowledge regarding the pathogenesis of B-cell lymphomas that can be EBV-associated including Burkitt lymphoma, plasmablastic lymphoma and classic Hodgkin lymphoma will be also explored.

Fibrin-associated EBV-positive Large B-Cell Lymphoma: An Indolent Neoplasm With Features Distinct From Diffuse Large B-Cell Lymphoma Associated With Chronic Inflammation

Incidental cases of localized fibrin-associated Epstein-Barr virus (EBV)+ large B-cell proliferations have been described at unusual anatomic sites and have been included in the category of diffuse large B-cell lymphoma associated with chronic inflammation (DLBCL-CI) in the WHO Classification. We describe 12 cases and review the literature to define their clinicopathologic spectrum and compare features with typical cases of DLBCL-CI. Median age was 55.5 years with a M:F ratio of 3. In all 12 cases, the lymphoma was an incidental microscopic finding involving atrial myxomas (n=3), thrombi associated with endovascular grafts (n=3), chronic hematomas (n=2), and pseudocysts (n=4). All cases tested were nongerminal center B-cell origin, type III EBV latency, and were negative for MYC rearrangements and alternative lengthening of telomeres by FISH. Most showed high CD30, Ki67, and PD-L1, and low to moderate MYC and p53 expression. Among 11 patients with detailed follow-up, 6 were treated surgically, 3 with cardiac or vascular lesions had persistent/recurrent disease at intravascular sites, and 4 died of causes not directly attributable to lymphoma. Reports of previously published fibrin-associated cases showed similar features, whereas traditional DLBCL-CI cases with a mass lesion had significantly higher lymphoma-associated mortality. Fibrin-associated EBV+ large B-cell lymphoma is clinicopathologically distinct from DLBCL-CI, warranting separate classification. Most cases, particularly those associated with pseudocysts, behave indolently with the potential for cure by surgery alone and may represent a form of EBV+ lymphoproliferative disease rather than lymphoma. However, primary cardiac or vascular disease may have a higher risk of recurrence despite systemic chemotherapy.

Chemopreventive Strategies for Inflammation-Related Carcinogenesis: Current Status and Future Direction

A sustained and chronically-inflamed environment is characterized by the presence of heterogeneous inflammatory cellular components, including neutrophils, macrophages, lymphocytes and fibroblasts. These infiltrated cells produce growth stimulating mediators (inflammatory cytokines and growth factors), chemotactic factors (chemokines) and genotoxic substances (reactive oxygen species and nitrogen oxide) and induce DNA damage and methylation. Therefore, chronic inflammation serves as an intrinsic niche for carcinogenesis and tumor progression. In this article, we summarize the up-to-date findings regarding definitive/possible causes and mechanisms of inflammation-related carcinogenesis derived from experimental and clinical studies. We also propose 10 strategies, as well as candidate agents for the prevention of inflammation-related carcinogenesis.

EBV-Positive B-Cell Proliferations of Varied Malignant Potential: 2015 SH/EAHP Workshop Report-Part 1

OBJECTIVES

The 2015 Workshop of the Society for Hematopathology/European Association for Haematopathology aimed to review B-cell proliferations of varied malignant potential associated with immunodeficiency.

METHODS

The Workshop Panel reviewed all cases of B-cell hyperplasias, polymorphic B-lymphoproliferative disorders, Epstein-Barr virus (EBV)-positive mucocutaneous ulcer, and large B-cell proliferations associated with chronic inflammation and rendered consensus diagnoses. Disease definitions, boundaries with more aggressive B-cell proliferations, and association with EBV were explored.

RESULTS

B-cell proliferations of varied malignant potential occurred in all immunodeficiency backgrounds. Presentation early in the course of immunodeficiency and in younger age groups and regression with reduction of immunosuppression were characteristic features. EBV positivity was essential for diagnosis in some hyperplasias where other specific defining features were absent.

CONCLUSIONS

This spectrum of B-cell proliferations show similarities across immunodeficiency backgrounds. Localized forms of immunodeficiency disorders arise in immunocompetent patients most likely due to chronic immune stimulation and, despite aggressive histologic features, often show indolent clinical behavior.

Recent Advances in Aggressive Large B-cell Lymphomas: A Comprehensive Review

Diffuse large B-cell lymphoma (DLBCL) is an aggressive disease with considerable heterogeneity reflected in the 2008 World Health Organization classification. In recent years, genome-wide assessment of genetic and epigenetic alterations has shed light upon distinct molecular subsets linked to dysregulation of specific genes or pathways. Besides fostering our knowledge regarding the molecular complexity of DLBCL types, these studies have unraveled previously unappreciated genetic lesions, which may be exploited for prognostic and therapeutic purposes. Following the last World Health Organization classification, we have witnessed the emergence of new variants of specific DLBCL entities, such as CD30 DLBCL, human immunodeficiency virus-related and age-related variants of plasmablastic lymphoma, and EBV DLBCL arising in young patients. In this review, we will present an update on the clinical, pathologic, and molecular features of DLBCL incorporating recently gained information with respect to their pathobiology and prognosis. We will emphasize the distinctive features of newly described or emerging variants and highlight advances in our understanding of entities presenting a diagnostic challenge, such as T-cell/histiocyte-rich large B-cell lmphoma and unclassifiable large B-cell lymphomas. Furthermore, we will discuss recent advances in the genomic characterization of DLBCL, as they may relate to prognostication and tailored therapeutic intervention. The information presented in this review derives from English language publications appearing in PubMed throughout December 2015. For a complete outline of this paper, please visit: http://links.lww.com/PAP/A12.

Epstein-Barr Virus-Positive Pyothorax-Associated Lymphoma Arising from a Posttraumatic Empyema

Pyothorax-associated lymphoma (PAL) develops from a pyothorax caused by an artificial pneumothorax created during the treatment of pulmonary tuberculosis or tuberculous pleuritis. We report the first case of Epstein-Barr virus (EBV)-positive PAL arising from a posttraumatic empyema. A 75-year-old woman with chronic posttraumatic empyema presented with a tumor, which was connected to the wall of a pyothorax in the right thoracic cavity. She had a history of trauma to the right chest, which had occurred at the age of 45 years and had caused the chronic posttraumatic empyema. Pathological features of the resected tumor were conclusive for a diagnosis of EBV-positive PAL. Although neither postoperative chemotherapy nor radiotherapy was performed, remission was maintained for 3 years until recurrence in the liver. Combination chemotherapy led to complete remission, and 9 years after the initial diagnosis of PAL, the patient is still alive. An intriguing finding is the phenotypic alteration during the disease course. Although the primary tumor was negative for CD20 and CD3, the recurrent tumor expressed both of these molecules. We discuss this case of PAL, which was not a complication of lung tuberculosis, and the aberrant chronological phenotypic change observed in the lymphoma cells, and compare it with a usual case of PAL.

Endobronchial T-cell lymphoma in a patient with chronic pyothorax

We report a very rare case of primary endobronchial peripheral T-cell lymphoma (PTCL) not otherwise specified (NOS), which presented as an endobronchial tumor obstructing the main airway. An 81-year-old man was referred to our hospital for a 1-month history of productive cough and wheeze. Computed tomography revealed chronic pyothorax with calcified foci in the right lung and a mass inside the bronchus intermedius. Flexible bronchoscopy identified an endobronchial tumor obstructing the bronchus intermedius. The biopsy specimen showed an infiltration composed predominantly of small atypical lymphocytes. Immunohistochemical analyses demonstrated that the proliferating cells were positive for CD3, CD4, and CD5 and negative for CD8 and CD20. Pathological tests confirmed that the case was PTCL-NOS. PTCL-NOS should be considered in the differential diagnosis of endobronchial tumors.

Diffuse Large B-cell Lymphoma Arising from Chronic Tuberculous Empyema

Pyothorax-associated lymphoma is a relatively rare type of lymphoma that occurs in patients who have long histories of tuberculous pleuritis or induced pneumothorax. It is a type of non-Hodgkin’s lymphoma of mainly the B-cell phenotype and is strongly associated with Epstein–Barr virus infection. A majority of these cases have been reported in Japan, although some cases have occurred in Western countries. Here, we describe a case of pyothorax-associated lymphoma in a patient with a 30-year history of chronic tuberculous empyema. The patient underwent decortication under the impression of chronic empyema with fistula. The histopathologic diagnosis was a diffuse large B-cell lymphoma associated chronic inflammation.

The histological classification of diffuse large B-cell lymphomas

Diffuse large B-cell lymphomas (DLBCLs) are aggressive B-cell neoplasms with considerable clinical, biologic, and pathologic diversity, in part reflecting the functional diversity of the B-cell system and multiple pathways of transformation. In recent years, the advent of new high-throughput genomic technologies has provided new insights into the biology of DLBCL, leading to the identification of distinct molecular identities and novel pathogenetic pathways. This increasing complexity had led to an expanding number of entities in the World Health Organization classification. Using a multi-modality approach, the updated 2008 classification delineated some new subgroups, including DLBCLs associated with particular age groups or specific anatomic sites, as well as two borderline categories (tumors at the interface between classical Hodgkin lymphoma and DLBCL as well as between Burkitt lymphoma and DLBCL). This article reviews the histopathologic features of the various aggressive B-cell lymphoma subtypes included in the 2008 classification, with emphasis on some of the new entities as well as areas of diagnostic challenge.

Comparison of the clinical courses and chemotherapy outcomes in metastatic colorectal cancer patients with and without active Mycobacterium tuberculosis or Mycobacterium kansasii infection: a retrospective study

Background

Although active Mycobacterium tuberculosis (MTB) or Mycobacterium Kansasii (MK) infection could be present in patients with metastatic colorectal cancer (m-CRC), no study is available on the clinical courses and chemotherapy outcomes of these patients. The present study therefore aimed to retrospectively examine whether m-CRC patients with and without active MTB or MK infection could receive cancer chemotherapy similarly.

Methods

This study enrolled 30 m-CRC patients who received first-line chemotherapy between January 31, 2006 and January 31, 2013 at our institution, The clinical courses and tumor response of those with and without active MTB or MK infection were examined and compared.

Results

Of 30 m-CRC patients, 6 had active MTB infection, 1 with active MK and the other 23 had neither MTB nor MK. No significant demographic differences were observed between patients with MTB or MK and those without. Chemotherapy response rates of all patients, those with MTB or MK, and those without were 40.0%, 28.6% and 43.5%, respectively. Among patients with MTB or MK, 1 treated with bevacizumab experienced grade-3 hemoptysis while others did not report any severe toxicity. Median survival time of all studied patients, those with MTB or MK, and those without was 26.3, 36.7 and 22.6 months, respectively. No significant difference in overall survival was observed between patients with MTB or MK and those without. Multivariate analysis revealed that performance status and liver metastasis were significant prognostic factors of overall survival (P = 0.004 and 0.030, respectively), whereas other factors, including MTB or MK infection, were not. In our study, all 7 patients with MTB or MK did not experience infection relapse during or after cancer chemotherapy.

Conclusions

Our results indicate that m-CRC patients with MTB or MK should be able to safely and effectively continue cancer chemotherapy to subsequently achieve comparable survival duration to those without the infection if they receive proper MTB or MK treatment.

Current status of treatment for primary effusion lymphoma

Primary effusion lymphoma (PEL) is a rare and aggressive B-cell non-Hodgkin's lymphoma that usually presents with malignant effusions without tumor masses. An extracavitary or solid variant of PEL has also been described. Human herpes virus 8/Kaposi sarcoma-associated herpes virus (HHV-8/KSHV) is universally associated with the pathogenesis of PEL. More than 70% of cases occur with concurrent Epstein-Barr virus infection, but its relation to the pathogenesis is unknown. Patients are found in the context of immunosuppressive states (HIV-1 infection, post-organ transplantation). PEL is usually treated with CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone)-like chemotherapy with antiretroviral therapy if HIV-1 is positive. However, it is generally resistant to chemotherapy with a short median survival of less than 6 months. The optimal treatment for PEL has not been established yet. More intensive chemotherapy, such as dose-adjusted EPOCH (DA-EPOCH; etoposide, prednisone, vincristine, cyclophosphamide and doxorubicin) and CDE (cyclophosphamide, doxorubicin, etoposide) are expected to show a favorable prognosis. Recently, the molecular steps in KSHV/HHV-8-driven oncogenesis have begun to be revealed, and molecular targeting therapies such as proteasome, NF-κB, cytokines and surface antigens would provide evidence for their clinical use.

Viral diseases affecting the pleura

BACKGROUND

Viruses affect the human body in multiple ways producing various disease states. The infections of the pulmonary parenchyma have been well described. However, there has been no current review of the literature pertaining to the pleura.

AIM

To review the available literature pertaining to diseases of the pleura that are caused by viral infections.

METHODS

A Medline search was performed and available research and review articles relating to viral infections that resulted in pleural effusions, pleural masses, pleural thickening, and pleural nodularity were reviewed.

CONCLUSION

There are numerous viruses that cause diseases of the pleura. Pleural effusions and lesions within the pleura are the most common presentation of the disease state. Polymerase chain reaction has the potential to further diagnose viral infections and expand our knowledge base in this field.

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.

A Unique "Composite" PTLD with Diffuse Large B-Cell and T/Anaplastic Large Cell Lymphoma Components Occurring 17 Years after Transplant

Posttransplant lymphoproliferative disorder (PTLD) comprises a spectrum ranging from polyclonal hyperplasia to aggressive monoclonal lymphomas. The majority of PTLDs are of B-cell origin while T-cell PTLDs and Hodgkin lymphoma-like PTLDs are uncommon. Here, we report a unique case of a 56-year-old man in whom a lymphoma with two distinct components developed as a duodenal mass seventeen years following a combined kidney-pancreas transplant. This PTLD, which has features not previously reported in the literature, consisted of one component of CD20 positive and EBV negative monomorphic diffuse large B-cell lymphoma. The other component showed anaplastic morphology, expressed some but not all T-cell markers, failed to express most B-cell markers except for PAX5, and was diffusely EBV positive. Possible etiologies for this peculiar constellation of findings are discussed and the literature reviewed for “composite-like” lymphomas late in the posttransplant setting.

The histological and biological spectrum of diffuse large B-cell lymphoma in the World Health Organization classification

Diffuse large B-cell lymphomas (DLBCLs) are aggressive B-cell lymphomas that are clinically, pathologically, and genetically diverse, in part reflecting the functional diversity of the B-cell system. The focus in recent years has been toward incorporation of clinical features, morphology, immunohistochemistry, and ever evolving genetic data into the classification scheme. The 2008 World Health Organization classification reflects this complexity with the addition of several new entities and variants. The discovery of distinct subtypes by gene expression profiling heralded a new era with a focus on pathways of transformation as well as a promise of more targeted therapies, directed at specific pathways. Some DLBCLs exhibit unique clinical characteristics with a predilection for specific anatomic sites; the anatomic site often reflects underlying biological distinctions. Recently, the spectrum of Epstein-Barr virus (EBV)-driven B-cell proliferations in patients without iatrogenic or congenital immunosuppression has been better characterized; most of these occur in patients of advanced age and include Epstein-Barr virus (EBV)-positive large B-cell lymphoma of the elderly. Human herpesvirus 8 is involved in the pathogenesis of primary effusion lymphoma, which can present as a "solid variant." Two borderline categories were created; one deals with tumors at the interface between classic Hodgkin lymphoma and DLBCL. The second confronts the interface between Burkitt lymphoma and DLBCL, so-called "B-cell lymphoma, unclassifiable, with features intermediate between DLBCL and Burkitt lymphoma" in the 2008 classification. Most cases harbor both MYC and BCL2 translocations and are highly aggressive. Another interesting entity is anaplastic lymphoma kinase-positive DLBCL, which renders itself potentially targetable by anaplastic lymphoma kinase inhibitors. Ongoing investigations at the genomic level, with both exome and whole-genome sequencing, are sure to reveal new pathways of transformation in the future.

The current lymphoma classification: new concepts and practical applications triumphs and woes

The World Health Organization (WHO) classification of lymphomas updated in 2008 represents an international consensus for diagnosis of lymphoid neoplasms based on the recognition of distinct disease entities by applying a constellation of clinical and laboratory features. The 2008 classification has refined and clarified the definitions of well-recognized diseases, identified new entities and variants, and incorporated emerging concepts in the understanding of lymphoid neoplasms. Rather than being a theoretical scheme this classification has used data from published literature. Recent knowledge of molecular pathways has led to identification and development of new diagnostic tools, like gene expression profiling, which could complement existing technologies. However, some questions remain unresolved, such as the extent to which specific genetic or molecular alterations define certain tumors. In general, practical considerations and economics preclude a heavily molecular and genetic approach. The significance of early or precursor lesions and the identification of certain lymphoid neoplasms is less clear at present, but understanding is evolving. The borderline categories having overlapping features with large B-cell lymphomas, as well as some of the provisional entities, are subject to debate and lack consensus in management. Lastly, the sheer number of entities may be overwhelming, especially, for the diagnosing pathologist, who do not see enough of these on a regular basis.

[Inflammatory bowel disease and lymphoproliferative disorders]

The risk of lymphoproliferative disorders (LPDs) has been reported to be increased in autoimmune diseases and chronic inflammatory diseases. Similar with other chronic inflammatory diseases such as rheumatoid arthritis, there is a concern about the risk of LPDs in patients with inflammatory bowel disease (IBD). Generally, in IBD patients, the risk of LPDs appears to be similar with or very slightly higher, compared to the general population. The association of therapeutic agents with the risk of LPDs is difficult to evaluate due to multiple other potentially involved factors and co-treatment with other agents. To date, data show that thiopurine is associated with a moderately increased risk of LPDs in patients with IBD. Evidence regarding the risk of LPDs in IBD patients using methotrexate is not sufficient, but the risk of LPDs seems low. The responsibility of anti-TNF-a agents on the risk of LPDs is difficult to determine, because most of IBD patients receiving anti-TNF-a agents are co-treated with thiopurines. Attention should be given to the high risk of hepatosplenic T-cell lymphoma in young male patients treated with anti-TNF-a agents together with thiopurines. The risk and benefit of immunosuppressive therapy for IBD should be carefully evaluated and individualized considering the risk of LPDs.

The 2008 WHO classification of lymphoid neoplasms and beyond: evolving concepts and practical applications

The World Health Organization classification of lymphoid neoplasms updated in 2008 represents a worldwide consensus on the diagnosis of these tumors and is based on the recognition of distinct diseases, using a multidisciplinary approach. The updated classification refined the definitions of well-recognized diseases, identified new entities and variants, and incorporated emerging concepts in the understanding of lymphoid neoplasms. However, some questions were unresolved, such as the extent to which specific genetic or molecular alterations define certain tumors, and the status of provisional entities, categories for which the World Health Organization working groups felt there was insufficient evidence to recognize as distinct diseases at this time. In addition, since its publication, new findings and ideas have been generated. This review summarizes the scientific rationale for the classification, emphasizing changes that have had an effect on practice guidelines. The authors address the criteria and significance of early or precursor lesions and the identification of certain lymphoid neoplasms largely associated with particular age groups, such as children and the elderly. The issue of borderline categories having overlapping features with large B-cell lymphomas, as well as several provisional entities, is reviewed. These new observations chart a course for future research in the field.

Aggressive B-cell lymphomas: a review of new and old entities in the WHO classification

Aggressive B-cell lymphomas are clinically and pathologically diverse and reflect multiple pathways of transformation. The 2008 World Health Organization (WHO) classification reflects this complexity with the addition of several new entities and variants. Whereas MYC translocations have long been associated with Burkitt lymphoma (BL), deregulation of MYC has been shown to occur in other aggressive B-cell lymphomas, most often as a secondary event. Lymphomas with translocations of both MYC and BCL2 are highly aggressive tumors, with a high failure rate with most treatment protocols. These "double-hit" lymphomas are now separately delineated in the WHO classification as B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma (DLBCL) and BL. A MYC translocation is also found uncommonly in DLBCL, but the clinical consequences of this in the absence of a double hit are not yet fully delineated. Most recently, MYC translocations have been identified as a common secondary event in plasma cell neoplasms, seen in approximately 50% of plasmablastic lymphoma. Another area that has received recent attention is the spectrum of EBV-driven B-cell proliferations in patients without iatrogenic or congenital immunosuppression; most of these occur in patients of advanced age and include the EBV-positive large B-cell lymphomas of the elderly.

Role of bacteria in oncogenesis

Although scientific knowledge in viral oncology has exploded in the 20th century, the role of bacteria as mediators of oncogenesis has been less well elucidated. Understanding bacterial carcinogenesis has become increasingly important as a possible means of cancer prevention. This review summarizes clinical, epidemiological, and experimental evidence as well as possible mechanisms of bacterial induction of or protection from malignancy.

Tuberculosis and malignancy

BACKGROUND

Tuberculosis (TB) and malignancy represent global threats claiming millions of lives and inflicting formidable suffering worldwide. Surprisingly, the pathophysiological and practical implications of their co-existence have received little attention.

METHODS

Therefore, we sought to review the available literature on the field and identify data regarding the association between TB and malignancy in order to highlight the neglected aspects of this association and probably derive clinically useful information. We searched PubMed up to June 2008 for case reports, case series, non-comparative and comparative studies that were written in English and reported data on the occurrence of both TB infection and a neoplastic disorder in the same patient(s). The development of mycobacterial infections in patients with immunocompromized conditions is well known and was considered outside the scope of this review.

EVIDENCE SYNTHESIS

The synthesis of the available evidence enabled us to establish three different types of association between malignancy and TB: (i) the development of cancer on the background of a previous tuberculous infection; (ii) the concurrent existence of TB and malignancy in the same patient(s) or clinical specimen(s); and (iii) the diagnostic challenges arising from the multi-faceted presentations of these two disorders.

CONCLUSION

We conclude that clinicians need to be aware of the protean manifestations of TB and cancer and maintain a high index of suspicion for simultaneous and/or misleading presentations. In addition, further research is required to determine if a tuberculous infection, being similar to other chronic infections and inflammatory conditions, may facilitate carcinogenesis.

Diffuse aggressive B-cell lymphomas

Diffuse aggressive B-cell lymphomas comprise a relatively common and increasingly diverse group of neoplasms. Newer modalities including gene expression profiling and an increasing panel of immunohistochemical markers have contributed to greater accuracy in defining these entities. Attention is paid not only to the neoplastic cells but also to the cellular and stromal milieu in which they proliferate. These distinctions may have therapeutic implications as well, with improved outcome related to newer and sometimes targeted therapies. At the same time there is increasing understanding of the overlap, which occurs in the grey zone between diffuse large B-cell lymphoma and Burkitt lymphoma as well as between diffuse large B-cell lymphoma and Hodgkin lymphoma. This review aims to provide practical insights in the correct identification and differential diagnosis of these lymphomas, with emphasis on the changes that have occurred with the publication of the 2008 World Health Organization updated classification.

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

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

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

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

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

The evolution of Epstein-Barr virus inferred from the conservation and mutation of the virus glycoprotein gp350/220 gene

To study variations of Epstein-Barr virus (EBV), we analyzed the gp350/220 gene for several cell lines and Japanese wild isolates using direct sequencing. The N-terminal region was highly conserved in all EBVs except for Jijoye/P3HR-1 and a few isolates. The variation of the region coincided with EBV types A and B (also referred to as types 1 and 2) and were, respectively, designated as the types a and b. The type A/a was detected in most Japanese cell lines and wild isolates, and was classified as China1 type with latent membrane protein (LMP) 1 gene. The type B/b was detected in only a few wild isolates with the Med and China2 types. The C-terminus had more diversity than the N-terminus and lacked the divergence between types A/a and B/b. The phylogenetic analyses of the gp350/220 and LMP1 genes may suggest a mode of EBV evolution into types A/a and B/b and then to LMP1 subtypes.