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Background: Helicobacter pylori ( Hp ) colonizes the human stomach and can induce gastric cancer and mucosa-associated lymphoid tissue (MALT) lymphoma. Clinical observations suggest a role for the Hp virulence factor cytotoxin-associated gene A (CagA) in pathogenesis. The pathogenic activity of CagA is partly regulated by tyrosine phosphorylation of C-terminal Glu-Pro-Ile-Tyr-Ala (EPIYA) motifs in host cells. However, CagA differs considerably in EPIYA motifs, whose functions have been well characterized in epithelial cells. Since CagA is fragmented in immune cells, different CagA variants may exhibit undetected functions in B cells., Methods: B cells were infected with Hp isolates and isogenic mutants expressing different CagA EPIYA variants. CagA translocation and tyrosine phosphorylation were investigated by Western blotting. Apoptosis was analyzed by flow cytometry and metabolic activity was detected by an MTT assay., Results: Isogenic CagA EPIYA variants are equally well translocated into B cells, followed by tyrosine phosphorylation and cleavage. B cell apoptosis was induced in a CagA-independent manner. However, variants containing at least one EPIYA-C motif affected metabolic activity independently of phosphorylation or multiplication of EPIYA-C motifs., Conclusions: The diverse structure of CagA regulates B cell physiology, whereas B cell survival is independent of CagA.

BACKGROUND Primary pulmonary mucosa-associated lymphoma tissue lymphoma is rare and is often misdiagnosed because of its diverse and nonspecific clinical features. The aim of this study was to raise awareness among clinicians and to share our experience of treating and managing such patients. MATERIAL AND METHODS This retrospective study was conducted between 1 January 2009 and 31 October 2017 at the First Affiliated Hospital of Guangxi Medical University. All cases were confirmed via pathology and immunohistochemistry. In addition, we reviewed all relevant literature. RESULTS Altogether, 21 patients (7 female, 14 male) with a median age of 54 (range, 19-84) years were diagnosed with primary pulmonary mucosa-associated lymphoma. Expiratory dyspnea, repeated cough and expectoration, and weight loss were the most common symptoms. Pulmonary lesions were found via physical examination in 10 patients who had no obvious symptoms. Chest computed tomography showed nodules, pulmonary consolidation, bronchial bronchogram, ground-glass opacity, and mediastinal lymph node enlargement. Some patients were misdiagnosed with tuberculosis and pneumonia, while others were initially diagnosed with cancer. Tumor pathology and immunocytochemistry indicated primary pulmonary mucosa-associated lymphoma tissue lymphoma. Six patients underwent chemotherapy, 5 underwent surgery, 4 underwent surgery and chemotherapy, 3 were only observed, and 3 refused treatment. CONCLUSIONS The development of primary pulmonary mucosa-associated lymphoid tissue lymphoma is slow and insidious. Having no specific clinical symptoms and imaging findings, it is easily misdiagnosed. Final diagnosis is made via pathologic evaluation and immunohistochemistry. Surgery and chemotherapy are the primary treatment modalities and yield a good prognosis.

Rationale: Mucosa-associated lymphoid tissue (MALT) lymphoma of the trachea is a rare disease that has been shown to be associated with chronic antigenic stimulation. There have been few reports of MALT lymphoma of the trachea in association with idiopathic pulmonary fibrosis (IPF)., Patient Concerns: A 73-year-old patient visited with a 2-year history of dyspnea on exertion and productive cough, which had worsened 1 month ago., Diagnoses: MALT lymphoma of the trachea associated with IPF., Interventions: After taking into consideration the age, poor performance status, and comorbidities of the patient and the extent of disease, we utilized an observational approach as a treatment strategy., Outcomes: The patient is well without any evidence of progression for 12 months since the initial diagnosis., Lessons: We present a case of MALT lymphoma of the trachea associated with IPF. A common predisposing factor may exist for tracheal MALT lymphoma and IPF. As there are no randomized clinical trials focusing on tracheal MALT lymphoma, individualized treatment decision is important, and in some cases, simply monitoring the patient might be the most appropriate approach.

Data on management of pediatric marginal zone lymphoma (MZL) are scarce. This retrospective study assessed characteristics and outcome in 66 patients who were <18 years old. Forty-four (67%) had an extranodal MZL (EMZL), 21 (32%) a nodal MZL (NMZL), and one patient a splenic MZL. Thirty-three patients (50%) received a variable combination of adjuvant chemotherapy/immunotherapy/radiotherapy, while the remainder, including 20 of 21 with NMZL, entered an active observation period. Overall survival was excellent (98 ± 2%), although 11 patients relapsed (17%; NMZL, n = 1; EMZL, n = 10), seven after any therapy and four after complete resection only. In conclusion, outcome of NZML, in particular, seems to be excellent after (in)complete resection and observation only., (© 2017 Wiley Periodicals, Inc.)

IgG4-related disease is a systemic disorder involving a spectrum of multiple indications, and various histopathological features are shared among different IgG4-related disease subtypes, which challenge diagnosis, although certain syndromes have organ-specific involvement. Among them, Mikulicz's disease affecting the salivary and lacrimal glands, distinguished by often elevated levels of serum IgG4, infiltration of IgG4 + plasma cells into target tissues, and diffuse swelling, mass formation, or fibrosis of affected organs. However, there are several diseases, which could manifest as salivary gland swelling, mimicking Mikulicz's disease, such as Sjogren's syndrome, mumps virus infection, obstruction of parotid duct, non-Hodgkin's lymphoma (NHL), and so on. So differential diagnosis is important and essential as to the salivary gland swelling. In this paper, we analyzed a case of a 59-year-old male with symmetric salivary gland swelling. Mikulicz's disease was misdiagnosed at the beginning without biopsy. Prednisone treatment ever seemed to be effective and antibiotics had no effect. Besides salivary involvement, the patient also manifested as testicle swelling and severe pancytopenia with the development of the disease, which rarely appeared in Mikulicz's disease. Physical examination showed skin, sclera yellow dye, swollen submandibular, sublingual and lacrimal gland and splenomegaly. As a result, biopsy of right submandibular gland was made, and mucosa-associated lymphoid tissue lymphoma was confirmed by morphology and immunohistochemistry. Bone marrow biopsy also confirmed that lymphoma cells were found in the bone marrow. Finally, the diagnosis of mucosa-associated lymphoid tissue lymphoma (Phase IVE, Group A) was made on the patient, who was transferred to the hematology department for the treatment. NHL, especially, primary extranodal lymphoma usually involves the salivary gland, and painless swelling of the salivary gland is a common manifestation, similar with Mikulicz's disease. So although salivary gland swelling is often associated with autoimmune diseases such as Sjogren's syndrome and IgG4-related disease, the awareness and suspicion of a possibility of NHL are essential for rheumatologists. Biopsy is a necessary examination to decrease or avoid misdiagnosis.

Background: Marginal zone B-cell lymphoma of the meninges is a rare pathologic subtype of central nervous system lymphoma that can mimic the radiologic appearance of meningioma., Case Description: We present a unique case of a 57-year-old man who presented with neurologic symptoms of severe headache, memory loss, mental status changes, and depression. Subsequent magnetic resonance imaging of the brain demonstrated an enhancing mass tracking along the anterior falx and anterior skull base with extension into the ethmoid sinus, which was radiographically consistent with meningioma. However, pathologic examination revealed numerous sheets of plasma cells and plasmacytoid lymphocytes that were immunopositive for CD20. These combined features were indicative of marginal zone B-cell lymphoma. No evidence of systemic disease was found., Conclusions: Although rare, marginal zone B-cell lymphoma must be considered in the differential diagnosis of an extra-axial enhancing mass. We review the contemporary literature and discuss preoperative radiologic differentiation of these 2 very different histopathologies., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objective: Primary pulmonary lymphomas (PPL) are rarely taken into consideration in the differential diagnosis of lung lesions. The aim of this report is to characterize the symptoms, diagnosis and treatment of primary MALT lymphoma of the lung., Case Report: We present the case of a 48-year-old man who was admitted to hospital with a history of coughing, fever, fatigue and non-specific lesions on his chest X-ray., Results: The patient was treated for pneumonia, but showed no improvement. A computer tomography revealed atypical lesions. After an initial examination and tests, no diagnosis could be established. A thoracotomy with an open lung biopsy was performed and MALT lymphoma was finally diagnosed. The patient underwent chemotherapy and showed a significant improvement., Conclusions: Primary MALT lymphoma is a rare disease and its diagnosis is difficult. There is no non-invasive test that is specific enough, so a proper diagnosis can only be established by a histopathological examination. The disease has a slow and mild course and the response to treatment is satisfactory.

Splenic marginal zone B-cell lymphoma (SMZBCL) is a rare non-Hodgkin B-cell lymphoma that presents with morphologically mature lymphoid cells corresponding in their immunological characteristics to secondary follicular marginal zone lymphocytes. It is clinically characterized by splenomegaly, moderate lymphocytosis, usually focal bone marrow lesion, sometimes moderate of monoclonal immunoglobulin in the serum (generally IgM or IgG) and/or urea, and a relatively benign course. Leishmaniasis is a transmissible natural focal infectious endemic disease that has a great diversity of clinical manifestations. The authors describe Russia's first case of SMZBCL concurrent with visceral leishmaniasis in a 52-year-old female patient admitted to a hematology hospital with weakness, splenomegaly, and lymphadenopathy. The simultaneous detection of lymphoma and leishmaniasis in the same biopsy specimen is extremely rare. Visceral leishmaniasis should be borne in mind as an opportunistic infection in patients with malignancies, particularly in immunocompromised persons who live or have stayed in the endemic areas.

Background: Central airway obstruction (CAO) may be caused by various etiologies. However, conventional chest X-rays are rarely diagnostic for patients with CAO., Case Presentation: We here described a 64-year-old asymptomatic female with tracheal mucosa-associated lymphoid tissue lymphoma discovered on spirometric findings during a complete physical examination. The plateau of forced expiratory flow was consistent with CAO. A decreased peak expiratory flow rate was noted at least 3 years before the diagnosis, and was attributed to an insufficient effort by the patient. Impulse oscillometric measurements, which were taken during quiet breathing and were effort-independent, suggested elevated respiratory resistance. These abnormalities completely disappeared after radiation therapy., Conclusion: The addition of impulse oscillometry to spirometry may be useful for screening CAO in routine health examinations.

MALT1 is the only known paracaspase and is a critical mediator of B- and T-cell receptor signalling. The function of the MALT1 gene is subverted by oncogenic chimeric fusions arising from the recurrent t(11;18)(q21;q21) aberration, which is the most frequent translocation in mucosa-associated lymphoid tissue (MALT) lymphoma. API2-MALT1-positive MALT lymphomas manifest antibiotic resistance and aggressive clinical behaviour with poor clinical outcome. However, the mechanisms underlying API2-MALT1-induced MALT lymphomagenesis are not fully understood. Here we show that API2-MALT1 induces paracaspase-mediated cleavage of the tumour suppressor protein LIMA1. LIMA1 binding by API2-MALT1 is API2 dependent and proteolytic cleavage is dependent on MALT1 paracaspase activity. Intriguingly, API2-MALT1-mediated proteolysis generates a LIM domain-only (LMO)-containing fragment with oncogenic properties in vitro and in vivo. Importantly, primary MALT lymphomas harbouring the API2-MALT1 fusion uniquely demonstrate LIMA1 cleavage fragments. Our studies reveal a novel paracaspase-mediated oncogenic gain-of-function mechanism in the pathogenesis of MALT lymphoma.

Helicobacter suis infects the stomachs of both animals and humans, and can induce gastric mucosa-associated lymphoid tissue (MALT) lymphomas. It is known that CXC chemokine ligand 13 (CXCL13) is highly expressed in the Helicobacter-infected mice and gastric MALT lymphoma patients, but the pathway that links the activation of CXCL13 and the formation of gastric MALT lymphomas remains unclear. In this study, we examined whether CXCL13 neutralization would interfere with the formation of gastric lymphoid follicles including B cells, CD4+T cells, dendritic cells (DCs), and follicular DCs (FDCs) in germinal centers to determine the role of CXCL13 in the formation of B-cell aggregates after H. suis infection. Moreover, the expression of genes associated with the lymphoid follicle formation was also effectively suppressed by anti-CXCL13 antibody treatment. These results suggest that the upregulation of CXCL13 has an important role in the development of gastric MALT lymphomas and highlight the potential of anti-CXCL13 antibody for protection against Helicobacter-induced gastric diseases.

This review will describe the current knowledge in the pathophysiology, diagnosis, prognosis and treatment of pulmonary MALT (Mucosa Associated Lymphoid Tissue) lymphoma. Pulmonary MALT lymphomas are low-grade B cell lymphoma and are the most frequent lymphomas arising from the lung. Tumour cells arise from mucosa associated lymphoid tissue. Unlike other sites, no pathogen has been associated with pulmonary location of MALT lymphoma. However addictive translocations involving the MALT1 gene are frequently evidenced Patients are frequently asymptomatic and present with a chronic alveolar opacity. Diagnosis requires histology that may be retrieved by minimally invasive procedures during bronchial endoscopy or by CT scan guided percutaneous biopsies. Prognosis is good and treatment may vary with abstention, surgery, radiotherapy, immunotherapy or chemotherapy.

Mucosa-associated lymphoid tissue (MALT) lymphoma usually arises from chronic inflammation. We herein report a case of small intestinal MALT lymphoma with protein-losing enteropathy (PLE). A 73-year-old woman presented with lower leg edema and severe hypoalbuminemia. She had a medical history of pylorus-preserving pancreaticoduodenectomy with Billroth II reconstruction. Oral and anal route double-balloon enteroscopies revealed irregular nodular mucosal lesions with erosion extending from the jejunum to terminal ileum. Histopathological evaluation of the biopsied mucosa showed proliferation of small-to-medium-sized lambda light chain-restricted B cells. Plasmacytic differentiation and lymphoepithelial lesions were present, leading to the diagnosis of MALT lymphoma. Tc-99m albumin scintigraphy indicated tracer exudation in the small bowel, suggesting the presence of PLE. Combination immunochemotherapy with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) regimen improved both MALT lymphoma and PLE, whereas rituximab monotherapy was not successful. This case is considered to be common type of MALT lymphoma at an uncommon site and is distinct from immunoproliferative small intestinal disease (IPSID). To our knowledge, this is the first case of non-IPSID-type small intestinal MALT lymphoma complicated by PLE. Gastrointestinal reconstruction may be responsible for underlying chronic inflammation via small intestinal bacterial overgrowth.

The gastrointestinal tract (GIT) is the most commonly involved site of extranodal lymphomas. The close association between chronic inflammation and specific GIT lymphomas not only provide interesting insights into the pathobiology of lymphomas but also poses unique diagnostic challenges. A clear understanding of marginal zone and mucosa associated lymphoid tissue (MALT) in health and disease is helpful to place GIT lymphomas in proper context. A wide variety of lymphomas besides MALT lymphomas occur in various parts of the GIT. The characteristic pathological, immunophenotypic, and genetic features of different GIT lymphomas categorized according to World Health Organization (WHO) classification are presented. The epidemiological, clinical, and pathological features of lymphomas occurring in each part of the GIT are summarized and the key points regarding lymphomas at each site are emphasized. A tabular summary of the important differential diagnostic considerations at each site is given and suggestions for a minimal diagnostic work up are provided.

We present a case of a 70-year-old HIV negative man with a five-year history of progressive dysnomia and new onset right extremity numbness, dysarthria, and blurry vision. On magnetic resonance imaging (MRI), an infiltrative enhancing tumor was noted. Follow up brain biopsy results revealed a small lymphocytic infiltrate with scattered plasma cells in a predominantly perivascular growth pattern. Flow-cytometric findings revealed a lambda monotypic B-cell population. The morphology and the flow cytometric findings were consistent with involvement by a low grade B-cell lymphoma. Subsequent positron emission tomography (PET) studies along with bone marrow biopsy and serum protein electrophoresis showed no evidence of systemic disease. The above findings are consistent with involvement by a non-dural extranodal marginal zone B-cell lymphoma (MZBCL) primary to the central nervous system (CNS). This is the first reported case of a primary CNS MZBCL with flow cytometric analysis. A review of literature on this rare entity is also included.

The optimal treatment strategy and outcome of non-gastric marginal zone lymphoma (MZL) remains undefined. The role of rituximab and fludarabine in MZL has not been critically appraised and compared with conventional chemotherapy. We retrospectively analyzed 81 consecutive patients with non-gastric MZL (mucosa-associated lymphoid tissue lymphoma, n=66; splenic MZL, n=11; nodal MZL, n=4). As a group, the treatment results were favorable, with an overall response rate of 87% and a complete response (CR) rate of 73%. The CR rate was similar for conventional chemotherapy, and rituximab- and fludarabine-containing regimens. However, the relapse rate was significantly decreased in rituximab- and fludarabine-containing regimens. The use of rituximab and fludarabine was associated with acceptable side effects. For splenic MZL, splenectomy was significantly associated with a superior CR rate. Early stage, good performance status, and low international prognostic index risk scores significantly impacted on CR rate and survivals. Rituximab and fludarabine were safe for non-gastric MZL and resulted in more durable remissions.

Patients with common variable immunodeficiency disorders (CVIDs) who developed B cell lymphoproliferation of indeterminate malignant potential are described in order to raise a discussion of the relationship between infection and lymphoproliferation in infection prone patients. Those with CVID are at risk of developing either polyclonal or monoclonal lymphoproliferation in part due to the dysregulation of their adaptive immune systems. The aetiologies of the lymphoproliferations are unknown but intriguing; the relevance of infection being particularly problematic. The patients described here demonstrate variability in preceding infection, age at presentation, response to antibiotics and other types of therapy as well as outcome. The question of treatment is also controversial; issues include whether antibiotics or chemotherapy are the first line of therapy in all patients and whether transformation to aggressive B cell malignancy is inevitable or depends on other factors and if so, the length of time for such progression.

This report describes a case of orbital B-cell lymphoma of extranodal marginal cell type with atypical clinical and radiographic features. This patient presented with choroidal effusion and optic disk swelling of the right eye. A CT scan revealed an intraconal mass surrounding the optic nerve and indenting the globe. A right orbitotomy with biopsy of the mass was performed. Histologic and immunohistochemical analysis confirmed a diagnosis of extranodal marginal zone B-cell lymphoma. This is the first case of primary orbital lymphoma presenting with choroidal effusion described in the literature.

Background and Aims: Our recent study revealed that per oral infection with Helicobacter heilmannii induced low-grade mucosa-associated lymphoid tissue (MALT) lymphoma in the gastric fundus of C57BL/6 mice after a period of 6 months, although the pathophysiological mechanism of lymphoma expansion remains to be clarified. The present study was undertaken to elucidate the interaction of this tumor with angiogenesis and lymphangiogenesis. In addition, the effect of Flt-4 antibodies on lymphoma expansion was investigated., Methods: C57BL/6 female mice infected with H. heilmannii for 3 months were used in the experiments. Localization of vascular endothelial growth factor C (VEGF-C) and Flt-4 immunoreactivity were detected by indirect immunohistochemical methods. Localization of lymphatic and vascular endothelial cells was investigated by localization of prox-1. In addition, Flt-4 antibody with and without Flt-1 or Flk-1 antibodies was administered i.p. to clarify their effects on tumor size., Results: MALT lymphoma has a rich microvascular network consisting of immature capillaries, lymphatics and venules. By immunohistochemical analysis, prox-1 immunoreactivity was observed mostly in the marginal area of the lymphoma, where VEGF-C and Flt-4 immunoreactivities were also seen. Stereomicroscopic study revealed that administration of Flt-4 and Flt-1 antibodies significantly reduced the surface area of the lymphoma in the mouse stomach., Conclusion: A VEGF-C-mediated mechanism plays an important role in the expansion of MALT lymphoma and the administration of VEGF receptor antibodies had a suppressive effect on tumor growth.

Background: : Bronchus-associated Lymphoid Tissue (BALT) lymphomas are a rare type of extranodal marginal zone lymphomas. They comprise 1% of lymphomas and more than two-thirds of all primary non-Hodgkin lymphoma (NHL) of the lung. BALT lymphomas arise from the bronchus-associated lymphoid tissue., Methods: This report describes five cases of BALT lymphoma and discusses the pathogenesis, diagnosis, prognosis and treatment of BALT lymphomas., Results: In our cohort of patients, patients were managed with surgery, watchful waiting, chemotherapy, immunotherapy, and chemoimmunotherapy. The outcomes are excellent and projected 5-year survival is 100%., Discussion: BALT lymphomas are associated with chronic inflammation, and they are often asymptomatic. They have an indolent course and the survival outcome is excellent with different treatment modalities such as surgery, watchful waiting, radiotherapy, chemotherapy, immunotherapy or chemoimmunotherapy.

Background: There are clinical reports that Helicobacter heilmannii, as well as Helicobacter pylori, has been clinically reported to cause gastric low-grade mucosa-associated lymphoid tissue-type (MALT) lymphoma, although its precise mechanism remains to be clarified. Thus, the present study was undertaken to elucidate the alteration of the microcirculatory structure and the relation to angiogenetic factors in mice infected with H. heilmannii for 3 and 6 months., Methods: Immunohistochemical studies have been performed by FITC-dextran intra-aortic infusion or CD31, vascular endothelial growth factor-A, cyclooxygenase 2 antibodies using our recently established model of gastric mucosa-associated lymphoid tissue-type gastric B-cell lymphoma in C57BL/6 mice., Results: Increased microcirculatory network was recognized surrounding the MALT lymphoma tissues by both the FITC-dextran infusion method and CD31 immunoreactivity. Vascular endothelial growth factor-A immunoreactivity was recognized within the lymphoma tissues as well as in the marginal area, while cyclooxygenase-2 immunoreactivity was localized in the area surrounding the MALT lymphoma tissues., Conclusion: Increased microvascular network as well as enhanced VEGF-A immunoreactivity was shown to be related to expansion of the MALT lymphoma formed by Helicobacter heilmannii infection.

Primary central nervous system (CNS) marginal zone B-cell lymphoma (MZBL) is very rare and shows an indolent disease course with potential of being cured. It seems to originate from meningothelial cells, and the most common site of occurrence is the dura of the cerebral convexity. Primary CNS MZBL is often misdiagnosed as meningioma because of its similar tumor locations and appearances on magnetic resonance imaging (MRI). Surgery, radiation therapy, chemotherapy, and combinations of these are considered treatment modalities depending on the case. Herein, we describe an 18-year-old man who presented with acute onset of right-sided central facial nerve palsy, right-sided hemiparesis with motor power grade 4+, dizziness, and dysarthria. After an MRI scan of the brain, wherein he was first diagnosed with high-grade glioma, a biopsy sample showed that he had primary CNS MZBL arising in the left basal ganglia. He was treated with radiation therapy, which resulted in complete remission for 1 year and 10 months up to the date of this case report. It is important to diagnose primary CNS MZBL correctly because it is curable without unnecessary invasive treatment in cases of localized disease.

To further characterize the genotypic features of splenic (S) and nodal (N) marginal zone lymphomas (MZL) we compared eight SMZL and five NMZL by array-based comparative genomic hybridization (aCGH). Arbitrarily, aberrations were divided into major imbalances, defined as gains or losses involving five or more contiguous genetic loci, and minor imbalances, defined as those involving four or fewer loci. SMZL, but not NMZL, demonstrated major imbalances. These included deletions involving various lengths of 7q (three cases), and 14q23q24 (one case) and gains of 9p13p21 (one case), 13q21q33 (one case) and 16p13.1 (one case). Common minor imbalances in SMZL were: loss of sonic hedgehog gene (SHH) at 7q36.2 (four cases), loss of protection of telomere 1 gene (POT1) at 7q31.32 (three cases), and gain of glioma associated oncogene 1 (GLI1) at 12q13.2 (three cases). Common minor alterations in NMZL were: loss of the fas-associated via death domain gene (FADD) at 11q13.2 (three cases) and gain of GLI1 (five cases). In conclusion, SMZL, but not NMZL, demonstrates large genomic imbalances and frequent loss of the 7q31.32 and 7q36.2 regions involving POT1 and SHH, respectively. In NMZL, loss of FADD and gain of GLI1 are frequent events.

The transcription factor NF-kappaB is a tightly regulated positive mediator of T- and B-cell development, proliferation, and survival. The controlled activity of NF-kappaB is required for the coordination of physiologic immune responses. However, constitutive NF-kappaB activation can promote continuous lymphocyte proliferation and survival and has recently been recognized as a critical pathogenetic factor in lymphoma. Various molecular events lead to deregulation of NF-kappaB signaling in Hodgkin disease and a variety of T- and B-cell non-Hodgkin lymphomas either up-stream or downstream of the central IkappaB kinase. These alterations are prerequisites for lymphoma cell cycling and blockage of apoptosis. This review provides an overview of the NF-kappaB pathway and discusses the mechanisms of NF-kappaB deregulation in distinct lymphoma entities with defined aberrant pathways: Hodgkin lymphoma (HL), diffuse large B-cell lymphoma (DLBCL), mucosa-associated lymphoid tissue (MALT) lymphoma, primary effusion lymphoma (PEL), and adult T-cell lymphoma/leukemia (ATL). In addition, we summarize recent data that validates the NF-kappaB signaling pathway as an attractive therapeutic target in T- and B-cell malignancies.

Gastric cancer remains a major health burden on many societies claiming hundreds of thousands of lives every year. The discovery of Helicobacter pylori has no doubt revolutionised our understanding of this malignancy, which is now regarded as a paradigm for infection-induced chronic inflammation-mediated cancer. In this paper, we discuss the evidence for the association between H. pylori and gastric adenocarcinoma and MALT lymphoma. We also discuss the pathogenesis of these two forms of cancer and the factors that determine their outcome. There is no doubt that the knowledge accumulated over the past two decades will be translated into eventual victory over this killer cancer, largely because we now appreciate that the best way to prevent the cancer is by preventing acquisition of the infection in the first place, or by eradicating the infection in infected subjects. Defining the optimal timing of intervention is going to be the challenge facing us over the next two decades.

Background: Mucosa-associated lymphoid tissue (MALT) lymphoma is a rare type of non-Hodgkin's lymphoma. The most common site for MALT lymphoma is the stomach., Case Report: We are reporting a case of a 57-year-old man who presented with obstructive jaundice and was found to have duodenal MALT lymphoma. Unlike gastric MALT lymphoma which is responsive to Helicobacter pylori eradication therapy, duodenal MALT lymphoma does not have a definitive treatment., Discussion: To our knowledge, this is the first report of a duodenal MALT lymphoma presenting clinically as obstructive jaundice. We describe this case to alert physicians to consider this disease in the differential diagnosis of obstructive jaundice.

Primary presentation of an intradural Non-Hodgkin's lymphoma is rare. Recently these B cell lymphomas of mucosa associated lymphoid tissue (MALT) have gained acceptance as an important pathological subtype and are distinguishable from other primary CNS lymphomas that exhibit aggressive behaviour. Over the past decade a number of these lesions have been reported to resemble a meningioma both intra-operatively and radiologically. The authors outline such a case of marginal zone B cell lymphoma that clinically and radiologically resembled a meningioma. This case illustrates the rare occurrence of low grade dural B cell lymphoma and the need to consider this entity in the differential diagnosis of CNS lesions, if appropriate targeted therapy is to be administered.

Background: The clinical features and clinical course of Helicobacter pylori-negative gastric mucosa-associated lymphoid tissue (MALT) lymphoma are unclear and a treatment strategy has not yet been established., Aim: To clarify the clinical differences between H. pylori-positive and H. pylori-negative gastric MALT lymphoma, we compared these two types of gastric MALT lymphoma., Materials and Methods: Fifty-seven patients with localized gastric MALT lymphoma were studied. H. pylori infection was present in 41 and absent in 16. Treatment consisted of antibiotic therapy and/or 30 Gy radiation therapy. Response assessment was performed every 3-6 months by esophagogastroduodenoscopy including gathering biopsy samples, endoscopic ultrasonography, clinical examination, and various imaging procedures. The median follow-up period was 37 months., Results: There were no significant differences between H. pylori-positive and H. pylori-negative gastric MALT lymphoma patients in terms of sex, age, stage, gross phenotype, affected area of the stomach, or the presence of monoclonality. Complete regression was achieved with antibiotic therapy against H. pylori-negative gastric MALT lymphoma in one of nine patients (11.1%), compared to 28 of 38 patients (73.7%) with H. pylori-positive gastric MALT lymphoma (p < .001). Radiation therapy showed high effectiveness for the local control of H. pylori-negative or antibiotic-resistant gastric MALT lymphoma (92.9%), although distant recurrence was recognized in three of 14 patients (21.4%). Two of 16 patients (12.5%) with H. pylori-negative gastric MALT lymphoma died because of the transformation of the disease into diffuse large B-cell lymphoma. There was a significant difference in both the overall and cause-specific survival rate between the two groups (p = .038)., Conclusion: Radiation therapy is the effective treatment for H. pylori-negative or antibiotic-resistant localized gastric MALT lymphoma. However, careful systemic follow-up for distant involvement should be required. Transformation into diffuse large B-cell lymphoma is thought to be the important cause of death in patients with gastric MALT lymphoma.

Extranodal marginal zone B-cell lymphomas of mucosa-associated lymphoid tissue (MALT) type occur in a number of anatomic sites, but share overlapping morphologic and immunophenotypic features. Helicobacter pylori infection has been identified as an etiologic factor in gastric MALT lymphoma, and a growing list of other infectious organisms have recently been shown to be associated with MALT lymphomas at other anatomic sites. Although cause and effect has not been established for most of these infectious agents, our understanding of the biology has significantly improved, in part through the application of standard cytogenetic analyses. The common karyotypic alterations that characterize MALT lymphomas include the trisomies 3 and 18, the translocations t(11;18)(q21;q21), t(1;14)(p22;q32), t(14;18)(q32;q21), t(3;14)(q27;q32), and the recently described t(3;14)(p14.1;q32). This apparent complexity of cytogenetic alterations that have now been implicated in the pathogenesis of extranodal MALT lymphoma serves as a paradigm for molecular cross talk in neoplastic disease. Recent data have shown that at least three of the disparate translocations affect a common signaling mechanism, and thus unify all three under a common pathogenesis, resulting in the constitutive activation of the nuclear factor kappa B (NF-kappaB) pathway. It may be that the new MALT-related translocation involving the FOXP1 gene and other as yet undiscovered translocations may all have in common increased NF-kappaB signaling.

Gastric B-cell lymphoma of mucosa-associated lymphoid tissue type is closely linked to chronic Helicobacter pylori infection. Most clinical and histopathological features of the tumor can be reproduced by prolonged Helicobacter infection of BALB/c mice. In this study, we have addressed the role of antigenic stimulation in the pathogenesis of the lymphoma by experimental infection with Helicobacter felis, followed by antibiotic eradication therapy and subsequent re-infection. Antimicrobial therapy was successful in 75% of mice and led to complete histological but not "molecular" tumor remission. Although lympho-epithelial lesions disappeared and most gastric lymphoid aggregates resolved, transcriptional profiling revealed the long-term mucosal persistence of residual B cells. Experimental re-introduction of Helicobacter led to very rapid recurrence of the lymphomas, which differed from the original lesions by higher proliferative indices and more aggressive behavior. Immunophenotyping of tumor cells revealed massive infiltration of lesions by CD4(+) T cells, which express CD 28, CD 69, and interleukin-4 but not interferon-gamma, suggesting that tumor B-cell proliferation was driven by Th 2-polarized, immunocompetent, and activated T cells. Tumors were also densely colonized by follicular dendritic cells, whose numbers were closely associated with and predictive of treatment outcome.

Mucosa-associated lymphoid tissue (MALT) lymphoma constitutes up to 90% of primary pulmonary lymphomas, but its diagnosis is often difficult. API2-MALT1 fusion is specific to MALT lymphoma and is detected in nearly half of the pulmonary cases. Cytologic examinations have played a pivotal role in the diagnosis of pulmonary tumors; however, cytologic specimens have only infrequently been used for molecular studies. In this study, we performed a multiplex reverse transcription-polymerase chain reaction (RT-PCR) assay to detect the API2-MALT1 fusion transcript in archival cytologic specimens used as RNA sources. We studied 3 pulmonary MALT lymphoma cases that were positive for the fusion gene as detected with RNA extracted from diagnostic histologic specimens. In 1 case, a conventional PCR clonality assay for the immunoglobulin heavy chain gene rearrangement failed to detect the monoclonality. In all 3 cases, the fusion transcript was successfully detected in the cytologic specimens of sputum, bronchoalveolar lavage fluid, bone marrow smears, and pleural effusions. This finding suggests that such specimens can be used as RNA sources in multiplex RT-PCR assays for the API2-MALT1 fusion transcript. The detection of API2-MALT1 fusion as carried out with these specimens would be useful as an ancillary assay for the diagnosis, staging, and follow-up of pulmonary MALT lymphoma.

Background: Mucosa-associated lymphoid tissue (MALT) lymphoma is usually associated with a chronic inflammatory disease from which lymphoid tissue of MALT type arises as a prerequisite for lymphoma proliferation. No well-characterized chronic inflammatory process has been identified in the larynx., Methods: We report a case of primary MALT lymphoma of the larynx associated with extraesophageal reflux, chronic laryngitis, and gastric Helicobacter pylori infection, raising the issue of its physiopathology and treatment., Results: Treatment of this MALT lymphoma of the larynx consisted of complete surgical excision associated with omeprazole, amoxicillin, and clarithromycin. No evidence of disease was observed after 24 months of follow-up., Conclusions: We may assume that chronic laryngitis could be a precursor to MALT lymphoma. This case is the first one to our knowledge of a primary MALT lymphoma of the larynx treated with conservative management combining surgical excision, reflux therapy, and eradication of gastric H. pylori infection., (2005 Wiley Periodicals, Inc.)

Mucosa-associated lymphoid tissue (MALT) lymphomas usually arise at sites of acquired MALT and are uncommon in native MALT (eg, Peyer patches and tonsil). Malignancy in these low-grade lymphomas is often inferred by immunoglobulin light-chain restriction and expression of CD43; molecular genetic evidence is sought only if these are in doubt. We report 6 cases (4 tonsils, 2 appendixes) of marginal zone (MZ) hyperplasia in children aged 3 to 11 years that, despite histologic and immunophenotypic features indicative of lymphoma, were polyclonal by molecular analysis. No lymphoma-directed therapy was given and patients remain alive and well (5 cases, median follow-up 35.3 months). The involved tonsil and appendix showed florid MZ hyperplasia with prominent intraepithelial B cells (IEBCs). The MZ B cells and IEBCs showed a high-proliferation fraction and a CD20(+), CD21(+), CD27(-), immunoglobulin (Ig) superfamily receptor translocation-associated 1-positive (IRTA-1(+)), CD43(+), multiple myeloma oncogene 1 (MUM-1), IgM(+)D(+) phenotype. Polymerase chain reaction (PCR), cloning, and sequencing of rearranged IgH and Iglambda genes (whole tissue sections [6 cases]; microdissected cells [2 cases]) showed that the MZ B cells and IEBCs were polyclonal and the IgH genes nonmutated. In contrast, MZ (intraepithelial) B cells of 6 control tonsils had a similar immunophenotype, except for expression of CD27 and polytypic light chains, whereas molecular studies showed that they were polyclonal with mutated Ig genes.

Introduction: The stomach is the most common site involved in primary gastrointestinal lymphoma. Gastric lymphoma originates from the mucosa-associated lymphoïd tissue so called MALT. It comprises a group of distinctive clinicopathological entities which are important to consider for clinical management., Current Knowledge and Key Points: In recent years, new diagnostic tools and new treatment strategies have improved the overall prognosis. One of the most exciting recent discoveries is the hypothesis that an infection by a bacterium, Helicobacter pylori has a decisive role in gastric lymphoma., Future Prospects and Projects: Recent advances, essentially due to molecular biology and cytogenetic studies may emerge with the understanding of pathogenesis and new prognostic factors of these different types of gastric lymphomas. It is the aim of our oncoming studies together with the evaluation of the new therapeutic options such as radiotherapy and monoclonal antibodies in prospective studies.