Effectiveness of Helicobacter pylori eradication in the treatment of early-stage gastric mucosa-associated lymphoid tissue lymphoma:An up-to-date meta-analysis

BACKGROUND Gastric mucosa-associated lymphoid tissue(MALT)lymphoma(GML)is usually a low-grade B-cell neoplasia strongly associated with Helicobacter pylori(H.pylori)-induced chronic gastritis.Clinical practice guidelines currently recommend H.pylori eradication as the preferred initial treatment for early-stage GML.To determine the practical effect of bacterial eradication as the sole initial therapy for early-stage GML,an updated analysis and review of available evidence is imperative.AIM To perform a meta-analysis to assess the rate of complete remission(CR)of H.pylori-positive early-stage GML following bacterial eradication.METHODS We performed independent,computer-assisted literature searches using the PubMed/MEDLINE,Embase,and Cochrane Central databases through September 2022.Prospective and retrospective observational studies evaluating the CR of early-stage GML following bacterial eradication in H.pylori-positive patients.The risk of bias was assessed using Joanna Briggs Institute(JBI)Critical Appraisal Tools.The pooled estimate of the complete histopathological remission rate and respective confidence intervals(95%CI)were calculated following the random-effects model.Heterogeneity and inconsistency were assessed using Cochran’s Q test and I2 statistic,and heterogeneity was defined as P<0.01 and I²>50%,respectively.Subgroup and meta-regression analyses were conducted to explore potential sources of heterogeneity.RESULTS The titles and abstracts of 1576 studies were screened;96 articles were retrieved and selected for full-text reading.Finally,61 studies were included in the proportional meta-analysis(P-MA).Forty-six were prospective and fifteen were retrospective uncontrolled,single-arm,observational studies.The overall risk of bias was low to moderate in all but a single report,with an average critical appraisal score across all studies of 79.02%.A total of 2936 H.pylori-positive early-stage GML patients,in whom H.pylori was successfully eradicated,were included in the analysis.The pooled CR of H.pylori-positive early-stage GML after bacterial eradication was 75.18%(95%CI:70.45%-79.91%).P-MA indicated the substantial heterogeneity in CR reported across studies(I2=92%;P<0.01).Meta-regression analysis identified statistically significant effect modifiers,including the proportion of patients with t(11;18)(q21;q21)-positive GML and the risk of bias in each study.CONCLUSION Comprehensive synthesis of available evidence suggests that H.pylori eradication is effective as the sole initial therapy for early-stage GML.Although the substantial heterogeneity observed across studies limits the interpretation of the pooled overall CR,the present study is a relevant to informing clinical practice.

Role of non-Helicobacter pylori gastric Helicobacters in helicobacter pylori-negative gastric mucosa-associated lymphoid tissue lymphoma

Marginal zone lymphomas rank as the third most prevalent form of non-Hodgkin B-cell lymphoma,trailing behind diffuse large B-cell lymphoma and follicular lymphoma.Gastric mucosa-associated lymphoid tissue lymphoma(GML)is a low-grade B-cell neoplasia frequently correlated with Helicobacter pylori(H.pylori)-induced chronic gastritis.On the other hand,a specific subset of individuals diagnosed with GML does not exhibit H.pylori infection.In contrast to its H.pylori-positive counterpart,it was previously believed that H.pylori-negative GML was less likely to respond to antimicrobial therapy.Despite this,surprisingly,increasing evidence supports that a considerable proportion of patients with H.pylori-negative GML show complete histopathological remission after bacterial eradication therapy.Nonetheless,the precise mechanisms underlying this treatment responsiveness are not yet fully comprehended.In recent years,there has been growing interest in investigating the role of non-H.pylori gastric helicobacters(NHPHs)in the pathogenesis of H.pylori-negative GML.However,additional research is required to establish the causal relationship between NHPHs and GML.In this minireview,we examined the current understanding and proposed prospects on the involvement of NHPHs in H.pylori-negative GML,as well as their potential response to bacterial eradication therapy.

Mucosa-associated lymphoid tissue lymphoma of the trachea treated with radiotherapy:A case report

BACKGROUND Mucosa-associated lymphoid tissue(MALT)lymphoma originates in the marginal zone of lymphoid tissue.lung is one of the most frequent non-gastrointestinal organs involved,here known as bronchus-associated lymphoid tissue(BALT)lymphoma.BALT lymphoma of unknown etiology,and most patients are asymptomatic.The treatment of BALT lymphoma is controversial.CASE SUMMARY A 55-year-old man admitted to hospital had a three-month history of progressively coughing up yellow sputum,chest stuffiness,and shortness of breath.Fiberoptic bronchoscopy revealed mucosal visible beaded bumps 4 cm from the tracheal carina at 9 o'clock and 3 o'clock,the right main bronchus,and the right upper lobe bronchus.Biopsy specimens showed MALT lymphoma.Computed tomography virtual bronchoscopy(CTVB)showed uneven main bronchial wall thickening and multiple nodular protrusion.BALT lymphoma stage IE was diagnosed after a staging examination.We treated the patient with radiotherapy(RT)alone.A total dose of 30.6 Gy/17 f/25 d was given.The patient had no obvious adverse reactions during RT.The CTVB was repeated after RT and showed that the right side of the trachea was slightly thickened.CTVB was repeated 1.5 mo after RT and again showed that the right side of the trachea was slightly thickened.Annual CTVB showed no signs of recurrence.The patient now has no symptoms.CONCLUSION BALT lymphoma is an uncommon disease and shows good prognosis.The treatment of BALT lymphoma is controversial.In recent years,less invasive diagnostic and therapeutic approaches have been emerging.RT was effective and safe in our case.The use of CTVB could provide a noninvasive,repeatable,and accurate method in diagnosis and follow-up.

Nomogram model predicting the overall survival for patients with primary gastric mucosa-associated lymphoid tissue lymphoma

BACKGROUND Increasingly extranodal marginal B-cell lymphoma of mucosa-associated lymphoid tissue,known as mucosa-associated lymphoid tissue(MALT)lymphoma,is a type of non-Hodgkin’s lymphoma.The prognosis of primary gastric MALT(GML)patients can be affected by many factors.Clinical risk factors,including age,type of therapy,sex,stage and family hematologic malignancy history,also have significant effects on the development of the disease.The available data are mainly focused on epidemiology;in contrast,few studies have investigated the prognostic variables for overall survival(OS)in patients with primary GML.Based on the realities above,we searched a large amount of data on patients diagnosed with primary GML in the Surveillance,Epidemiology and End Results(SEER)database.The aim was to develop and verify a survival nomogram model that can predict the overall survival prognosis of primary GML by com-bining prognostic and determinant variables.AIM To create an effective survival nomogram for patients with primary gastric GML.METHODS All data of patients with primary GML from 2004 to 2015 were collected from the SEER database.The primary endpoint was OS.Based on the LASSO and COX regression,we created and further verified the accuracy and effectiveness of the survival nomogram model by the concordance index(C-index),calibration curve and timedependent receiver operating characteristic(td-ROC)curves.RESULTS A total of 2604 patients diagnosed with primary GML were selected for this study.A total of 1823 and 781 people were randomly distributed into the training and testing sets at a ratio of 7:3.The median follow-up of all patients was 71 mo,and the 3-and 5-year OS rates were 87.2%and 79.8%,respectively.Age,sex,race,Ann Arbor stage and radiation were independent risk factors for OS of primary GML(all P<0.05).The C-index values of the nomogram were 0.751(95%CI:0.729-0.773)and 0.718(95%CI:0.680-0.757)in the training and testing cohorts,respectively,showing the good discrimination ability of the nomogram model.Td-ROC curves and calibration plots also indicated satisfactory predictive power and good agreement of the model.Overall,the nomogram shows favorable performance in discriminating and predicting the OS of patients with primary GML.CONCLUSION A nomogram was developed and validated to have good survival predictive performance based on five clinical independent risk factors for OS for patients with primary GML.Nomograms are a low-cost and convenient clinical tool in assessing individualized prognosis and treatment for patients with primary GML.

Primary rectal mucosa-associated lymphoid tissue lymphoma treated with only endoscopic submucosal dissection:A case report

BACKGROUND Mucosa-associated lymphoid tissue(MALT)lymphoma is a distinct subtype of non-Hodgkin B cell lymphoma that mostly involves the gastrointestinal tract.The stomach is the most commonly affected site whereas colorectal involvement occurs very rarely.Given its rarity,the management and clinical outcome of colorectal MALT lymphoma are not well established yet.CASE SUMMARY From the superficial capillary bed in the lower rectum.Endoscopic ultrasonography showed homogenous hypoechoic lesions in the deep mucosal layer.Endoscopic submucosal dissection(ESD)was done for accurate histologic diagnosis and treatment and both the rectal lesions were completely removed en bloc and subsequently diagnosed as primary rectal MALT lymphoma.Herein,we report a case of primary rectal MALT lymphoma in a 68-year-old woman that was treated by only ESD,and the 12-month follow-up revealed no tumour recurrence.CONCLUSION These results of our case and previous reports suggest that endoscopic resection alone may be a feasible and safe treatment for primary colorectal MALT lymphoma and allows organ preservation.

Laterally spreading tumor-like primary rectal mucosa-associated lymphoid tissue lymphoma:A case report

BACKGROUND Colorectal mucosa-associated lymphoid tissue(MALT)lymphoma is a rare disease,and only a few cases have been reported to date.It has no specific clinical presentations and shows various endoscopic appearances.There is no uniform consensus on its treatment.With the advancement of endoscopic technology,endoscopic treatment has achieved better results in individual case reports of early-stage patients.CASE SUMMARY We report a case of rectal MALT in a 57-year-old Chinese man with no symptoms who received endoscopy as part of a routine physical examination,which incidentally found a 25 mm×20 mm,laterally spreading tumor(LST)-like elevated lesion in the rectum.Therefore,he was referred to our hospital for further endoscopic treatment.Complete and curable removal of the tumor was performed by endoscopic submucosal dissection.We observed enlarged and dilated branch-like vessels similar to those of gastric MALT lymphoma on magnifying endoscopy with narrow-band imaging.And immunopathological staining showed hyperplastic capillaries in the mucosa.Histopathological findings revealed diffusely hyperplastic lymphoid tissue in the lamina propria,with a visible lymphoid follicle structure surrounded by a large number of diffusely infiltrated lymphoid cells that had a relatively simple morphology and clear cytoplasm.In addition,immunohistochemical analysis suggested strongly positive expression for CD20 and Bcl-2.Gene rearrangement results showed positivity for IGH-A,IGH-C,IGK-B,and IGL.Taking all the above findings together,we arrived at a diagnosis of extranodal marginal zone B-cell lymphoma of MALT lymphoma. Positron emission tomography-computed tomographyexamination showed no other lesions involved. The patient will be followed byperiodic endoscopic observation.CONCLUSIONIn conclusion, we report a case of rectal MALT with an LST-like appearancetreated by endoscopic submucosal dissection. Further studies will be needed toexplore the clinical behavior, endoscopic appearance, and treatment of rectalMALT.

Synchronous early gastric and intestinal mucosa-associated lymphoid tissue lymphoma in a Helicobacter pylori-negative patient:A case report

BACKGROUND Mucosa-associated lymphoid tissue(MALT)lymphoma occurs largely in the digestive tract,with the stomach being the most commonly affected organ,followed by the small intestine,large intestine,and esophagus.It is rarely found in both the stomach and colon.Helicobacter pylori(H.pylori)infection is strongly associated with gastric MALT lymphoma,although there is a small number of H.pylori-negative gastric MALT lymphomas.Diagnosis of MALT lymphoma is challenging because of nonspecific symptoms and diverse presentations of endoscopic findings.CASE SUMMARY We report a case of an asymptomatic patient who during screening endoscopy and was found to have stromal tumor-like submucosal uplift lesions in the stomach body and polypoid lesions in the rectum.After endoscopic resection,the patient was diagnosed with multiple early simultaneous gastrointestinal MALT lymphomas.CONCLUSION This study may help improve our understanding of MALT lymphomas and multifocal lesions treated using early endoscopy.

CT and MR imaging findings of ocular adnexal mucosa-associated lymphoid tissue lymphoma associated with IgG4-related disease: multi-institutional case series

AIM:To report CT and MR imaging findings of ocular adnexal mucosa-associated lymphoid tissue lymphoma associated with IgG4-related disease(IgG4-MALT lymphoma),a rare but clinically important complication of ocular adnexal IgG4-related disease.METHODS:We retrospectively reviewed all cases of histologically confirmed ocular adnexal IgG4-related disease at three ter tiary and one secondary referral centers,between February 2003 and December 2016.Seven cases of histopathologically diagnosed IgG4-MALT lymphoma were identified.CT and MR images were analyzed by consensus of two experienced head and neck radiologists.RESULTS:Lacrimal glands were the main site of involvement in all seven patients.The lesions typically showed well-demarcated margins,iso-to hyperattenuation on precontrast CT,T2 hypo-to isointensity,T1 isointensity,and homogenous internal architecture with homogenous enhancement pattern.Lesions were mostly hyperdense and isointense to normal extraocular muscles on postcontrast CT and MR images,respectively.CONCLUSION:Unlike in typical ocular adnexal IgG4-related disease,T2 isointensity and hyperattenuation on precontrast CT images were noted in some IgG4-MALT lymphoma cases.Although the findings may be nonspecific,the possibility of accompanying MALT lymphoma may need to be considered,when ocular adnexal lesions in patients clinically suspected of having IgG4-related disease are refractory to glucocorticoids and show T2 isointensity and hyperattenuation on precontrast CT for the optimal management of the patients.However,this is a case series of a very rare complication of ocular adnexal IgG4-related disease,and thus caution is warranted to generalize the conclusion.

Successful treatment of an enormous rectal mucosa-associated lymphoid tissue lymphoma by endoscopic full-thickness resection:A case report

BACKGROUND Colorectal mucosa-associated lymphoid tissue lymphoma(MALToma),a rare kind of nongastric MALToma,lacks consensus on its endoscopic features and standard therapies.According to previous studies on the clinical characteristics and outcomes of colorectal MALToma,endoscopic resection remains a good therapeutic strategy.CASE SUMMARY A 71-year-old woman suffered intermittent hematochezia for 1 mo,accompanied with abdominal pains but without weight loss,fever,chills or fatigue.Colonoscopy showed a massive hemispheric mass with rough and hyperemic mucosa in the lower rectum.Narrow-band imaging magnifying endoscopy detected some branching abnormal blood vessels and disappearance of glandular structure,which was similar with the tree-like appearance sign in gastric MALToma.Endoscopic ultrasonography revealed the lesion to be hypoechoic,boundary-defined,and echo uniform inside,originating from the muscularis propria.Abdominal enhanced computed tomography(CT)demonstrated a soft tissue mass with defined boundary.No enlarged superficial lymph nodes were detected by B-mode ultrasound.C13-urea breath test and serum Helicobacter pylori antibody were both negative.The patient underwent endoscopic full-thickness resection.Postoperative pathological analysis indicated colorectal MALToma.The patient remained asymptomatic after discharge,and follow-up positron emission tomography–CT and colonoscopy showed no residual lesion,remnants or lymph node metastasis.CONCLUSION This case provides new information on the specific endoscopic features of colorectal MALToma and an alternative treatment for patients.

Synchronous colonic mucosa-associated lymphoid tissue lymphoma found after surgery for adenocarcinoma:A case report and review of literature

BACKGROUND Mucosa-associated lymphoid tissue (MALT) lymphoma is a subtype of non-Hodgkin lymphoma that is mainly involved in the gastrointestinal tract. Thesynchronous occurrence of colonic MALT lymphoma and adenocarcinoma in thesame patient is extremely rare. We here report a case of synchronous colonicMALT lymphoma found on surveillance colonoscopy five months after surgeryand chemotherapy for sigmoid adenocarcinoma.CASE SUMMARY A 67-year-old man was admitted because of hematochezia for two months.Colonoscopy suggested a colonic tumor before hospitalization. Abdominalcomputed tomography (CT) revealed local thickening of the sigmoid colon. Thepatient underwent a left hemicolectomy with local lymph node dissection. Thehistopathology revealed moderately differentiated adenocarcinoma and partiallymucinous adenocarcinoma. The pTNM stage was T3N1Mx. The patient receivedchemotherapy with six cycles of mFOLFOX6 after surgery. Colonoscopy wasperformed five months later and revealed single, flat, polypoid lesions of thecolon 33 cm away from the anus. Subsequently, the patient underwent endoscopic mucosal resection for further diagnosis. The pathological diagnosis was MALTlymphoma. Positron emission tomography /CT suggested metastasis. The patientrefused further treatment and died ten months later.CONCLUSION Colonic MALT lymphoma may occur after surgery and chemotherapy foradenocarcinoma as a synchronous malignancy. Regular surveillance colonoscopyand careful monitoring after surgery are critical.

Primary mucosa-associated lymphoid tissue lymphoma in the midbrain:A case report

BACKGROUND Primary non-dural central nervous system mucosa-associated lymphoid tissue(MALT)lymphoma is a rare indolent B-cell lymphoma,with only a few reported cases worldwide.CASE SUMMARY A 33-year-old man presented with a 5-mo history of left blepharoptosis and a 4-mo history of right limb numbness and weakness.Magnetic resonance imaging showed a significantly enhanced mass in the left midbrain.Subsequent positron emission tomography revealed that the lesion had increased glucose uptake.A stereotactic robotic biopsy supported a diagnosis of MALT lymphoma.Then he was treated with radiation therapy(30Gy/15F),which resulted in complete remission.We also review the literature on brain parenchymal-based MALT lymphoma,including the clinical presentation,treatment options,and outcomes.CONCLUSION Although there is no consensus on the optimal treatment for this rare disease,patients can respond well when treated with radiotherapy alone.

Rare primary rectal mucosa-associated lymphoid tissue lymphoma with curative resection by endoscopic submucosal dissection:A case report and review of literature

BACKGROUND Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue(MALT lymphoma)occurs in approximately 9%of non-Hodgkin B-cell lymphomas.The gastrointestinal tract is the most commonly affected site of the extranodal forms of primary non-Hodgkin’s lymphomas.However,it rarely occurs within the rectum,and at present,there is no consensus on its diagnosis and treatment at this site.CASE SUMMARY We report a rare laterally spreading tumour-like rectal MALT lymphoma case in which the diagnosis and the depth of infiltration were determined by magnifying endoscopy and ultrasonic endoscopy.Then,the lesion was en bloc resected by endoscopic submucosal dissection(ESD)alone.The lesion was confirmed as MALT lymphoma by haematoxylin and eosin staining,immunohistochemical staining and gene arrangement analysis.Surveillance exams have indicated a 2-year disease-free survival for this patient.CONCLUSION We report a rare primary rectal MALT lymphoma that was curable with resection by ESD.ESD is a safe and effective therapeutic option for rectal MALT lymphoma.

Mucosa-associated lymphoid tissue lymphoma in the terminal ileum:A case report

BACKGROUND The lymphoma of the mucosa-associated lymphoid tissue(MALT)is predominantly found in the stomach.The few cases reported in the literature of MALT lymphomas affecting the ileum are in patients who are already symptomatic and with clear advanced endoscopic findings.We present the first case of an asymptomatic female patient who underwent colonoscopy as a routine examination with the findings of an ulcer in the distal ileum region,which histopathological examination and associated immunohistochemistry revealed the diagnosis of MALT lymphoma.CASE SUMMARY A 57-year-old asymptomatic female patient underwent a colonoscopy exam for screening.The examination revealed an ulcer of medium depth with well-defined borders covered by a thin layer of fibrin and a halo of hyperemia in the distal ileum portion.Findings are nonspecific but may signal infections by viruses,protozoa,and parasites or inflammatory diseases such as Crohn's disease.Biopsies of the ulcer were taken.The anatomopathological result revealed an atypical diffuse lymphocytic infiltrate of small cells with a characteristic cytoplasmic halo of marginal zone cells.The immunohistochemical study was performed and the results demonstrated a negative neoplastic infiltrate for the expression of cyclin D1 and cytokeratin AE1/AE3 and a positive for BCL60 in the germinal center.The test also revealed CD10 positivity in the glandular epithelium and germinal center of a reactive follicle with dual-labeling of CD20 and CD3 demonstrating the B lymphocyte nature of the neoplastic infiltrate.In BCL2 protein labeling,the neoplastic infiltrate is strongly positive with a negative germinal center.The findings are consistent with immunophenotype B non-Hodgkin's lymphoma,better classified as extranodal MALT.The patient was treated with chemotherapy and showed complete regression of the disease,as evidenced by colonoscopy performed after treatment.CONCLUSION MALT lymphomas in the terminal ileum are extremely rare and only 4 cases have been reported in the literature.Given the low sensitivity and specificity of endoscopic images in these cases,the pathology can be confused with other important differential diagnoses such as inflammatory diseases or infectious diseases and which makes the biopsy important,even in asymptomatic patients,paired with anatomopathological analysis and immunohistochemistry which is the gold standard for correct diagnosis.

Helicobacter pylori and gastric mucosa-associated lymphoid tissue lymphoma:Recent progress in pathogenesis and management

Recent progress in the research regarding the molecular pathogenesis and management of gastric mucosaassociated lymphoid tissue(MALT)lymphoma is reviewed.In approximately 90%of cases,Helicobacter pylori(H.pylori)infection plays the causative role in the pathogenesis,and H.pylori eradication is nowadays the first-line treatment for this disease,which leads to complete disease remission in 50%-90%of cases.In H.pylori-dependent cases,microbe-generated immune responses,including interaction between B and T cells involving CD40 and CD40L co-stimulatory molecules,are considered to induce the development of MALT lymphoma.In H.pylori-independent cases,activation of the nuclear factor-κB pathway by oncogenic products of specific chromosomal translocations such as t(11;18)/API2-MALT1,or inactivation of tumor necrosis factor alpha-induced protein 3(A20)are considered to contribute to the lymphomagenesis.Recently,a largescale Japanese multicenter study confirmed that the long-term clinical outcome of gastric MALT lymphoma after H.pylori eradication is excellent.Treatment modalities for patients not responding to H.pylori eradication include a"watch and wait"strategy,radiotherapy,chemotherapy,rituximab immunotherapy,and a combination of these.Because of the indolent behavior of MALT lymphoma,second-line treatment should be tailored in consideration of the clinical stage and extent of the disease in each patient.

Role of Helicobacter pylori virulence factor cytotoxin-associated gene A in gastric mucosa-associated lymphoid tissue lymphoma

Helicobacter pylori(H.pylori)infection might initiate and contribute to the progression of lymphoma from gastric mucosa-associated lymphoid tissue(MALT).Increasing evidence shows that eradication of H.pylori with antibiotic therapy can lead to regression of gastric MALT lymphoma and can result in a 10-year sustained remission.The eradication of H.pylori is the standard care for patients with gastric MALT lymphoma.Cytotoxin-associated gene A(CagA)protein,one of the most extensively studied H.pylori virulence factors,is strongly associated with the gastric MALT lymphoma.CagA possesses polymorphisms according to its C-terminal structure and displays different functions among areas and races.After being translocated into B lymphocytes via typeⅣsecretion system,CagA deregulates intracellular signaling pathways in both tyrosine phosphorylation-dependent and-independent manners and/or some other pathways,and thereby promotes lymphomagenesis.A variety of proteins including p53and protein tyrosine phosphatases-2 are involved in the malignant transformation induced by CagA.Mucosal inflammation is the foundational mechanism underlying the occurrence and development of gastric MALT lymphoma.

Helicobacter pylori infection in gastric mucosa-associated lymphoid tissue lymphoma

Gastrointestinal lymphoma is the most common type of extranodal lymphoma,and most commonly affects the stomach.Marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue(MALT)and diffuse large B-cell lymphoma are the most common histologic types of gastric lymphoma.Despite its increasing incidence,diagnosis of gastric lymphoma is difficult at an earlier stage due to its nonspecific symptoms and endoscopic findings,and,thus,a high index of suspicion,and multiple,deep,repeated biopsies at abnormally and normally appearing sites in the stomach are needed.In addition,testing for Helicobacter pylori(H.pylori)infection and endoscopic ultrasonography to determine the depth of tumor invasion and involvement of regional lymph nodes is essential for predicting response to H.pylori eradication and for assessment of disease progression.In addition,H.pylori infection and MALT lymphoma development are associated,and complete regression of low-grade MALT lymphomas after H.pylori eradication has been demonstrated.Radiotherapy and/or chemotherapy can be used in cases that show poor response to H.pylori eradication,negativity for H.pylori infection,or high-grade lymphoma.

Role of Helicobacter pylori in gastric mucosa-associated lymphoid tissue lymphomas

Mucosa-associated lymphoid tissue(MALT)lymphoma is an indolent extranodal marginal zone B-cell lymphoma,originating in acquired MALT that is induced in mucosal barriers as part of a normal adaptive immune response to a chronic immunoinflammatory stimulus,most notably chronic infection by Helicobacter pylori(H.pylori).This antigenic stimulation initially leads to lymphoid hyperplasia;the acquisition of additional genetic aberrations culminates in the activation of intracellular survival pathways,with disease progression due to proliferation and resistance to apoptosis,and the emergence of a malignant clone.There are descriptions of MALT lymphomas affecting practically every organ and system,with a marked geographic variability partially attributable to the epidemiology of the underlying risk factors;nevertheless,the digestive system(and predominantly the stomach)is the most frequently involved location,reflecting the gastrointestinal tract’s unique characteristics of contact with foreign antigens,high mucosal permeability,large extension and intrinsic lymphoid system.While early-stage gastric MALT lymphoma can frequently regress after the therapeutic reversal of the chronic immune stimulus through antibiotic eradication of H.pylori infection,the presence of immortalizing genetic abnormalities,of advanced disease or of eradication-refractoriness requires a more aggressive approach which is,presently,not consensual.The fact that MALT lymphomas are rare neoplasms,with a worldwide incidence of 1-1.5 cases per105population,per year,limits the ease of accrual of representative series of patients for robust clinical trials that could sustain informed evidence-based therapeutic decisions to optimize the quality of patient care.

Primary thymic mucosa-associated lymphoid tissue lymphoma with multiple thin walled lung cysts: case report and literature review

Mucosa-associated lymphoid tissue （MALT） lymphoma of the thymus is rare. We reported a case of a 37-year-old Chinese female with Sjtgren＇s syndrome and hyperglobulinemia. She suffered from chronic cough for 3 weeks. Chest computed tomography （CT） demonstrated a multiloculated cystic mass in mediastinum prevascular space and multiple lung cysts. Laboratory exam of autoimmune markers showed positive of antinuclear antibody （ANA）, Sjtgren＇s syndrome A （SSA）, Sjtgren＇s syndrome B （SSB）, and rheumatoid factors （RF）. Thymectomy with lymph node dissection was performed. The pathology report revealed thymic extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue. Under immunohistochemical stains, CD20 and Bcl-2 were positive. No evidence of recurrence of disease was found.

A case of mucosa-associated lymphoid tissue lymphoma of the gastrointestinal tract showing extensive plasma cell differentiation with prominent Russell bodies

A 73-year-old Japanese woman was hospitalized for detailed examination of nausea, diarrhea and loss of appetite. Atypical erosion in the ileum was found on endoscopy. Biopsy of this erosion showed proliferation of cells containing numerous Russell bodies. Differential diagnoses considered were Russell body enteritis, crystal-storing histiocytosis, Mott cell tumor, immunoproliferative small intestinal disease(IPSID) and mucosaassociated lymphoid tissue(MALT) lymphoma. The cells containing prominent Russell bodies showed diffuse positivity for CD79 a and CD138, but negative results for CD20, CD3, UCHL-1, CD38 and CD68. Russell bodies were diffusely positive for lambda light chain, but negative for kappa light chain, and immunoglobulin(Ig)G, Ig A and Ig M. Based on these findings, Russell body enteritis, crystal-storing histiocytosis and IPSID were ruled out. As the tumor formed no mass lesions and was restricted to the gastrointestinal tract, MALT lymphoma with extensive plasma cell differentiation was finally diagnosed. The patient showed an unexpectedly aggressive clinical course. The number of atypical lymphocytes in peripheral blood gradually increased and T-prolymphocytic leukemia(T-PLL) emerged. The patient died of T-PLL 7 mo after admission. Autopsy was not permitted.

Management of gastric mucosa-associated lymphoid tissue lymphoma in patients with extra copies of the MALT1 gene

AIM To identify the clinical features of gastric mucosaassociated lymphoid tissue(MALT) lymphoma with extra copies of MALT1.METHODS This is a multi-centered,retrospective study. We reviewed 146 patients with MALT lymphoma in the stomach who underwent fluorescence in situ hybridization analysis for t(11;18) translocation. Patients were subdivided into patients without t(11;18) translocation or extra copies of MALT1(Group A,n = 88),patients with t(11;18) translocation(Group B,n = 27),and patients with extra copies of MALT1(Group C,n = 31). The clinical background,treatment,and outcomes of each group were investigated.RESULTS Groups A and C showed slight female predominance,whereas Group B showed slight male predominance. Mean ages and clinical stages at lymphoma diagnosis were not different between groups. Complete response was obtained in 61 patients in Group A(69.3%),22 in Group B(81.5%),and 21 in Group C(67.7%). Helicobacter pylori(H. pylori) eradication alone resulted in complete remission in 44 patients in Group A and 13 in Group C. In Group B,14 patients underwent radiotherapy alone,which resulted in lymphoma disappearance. Although the difference was not statistically significant,event-free survival in Group C tended to be inferior to that in Group A(P = 0.10).CONCLUSION Patients with t(11;18) translocation should be treated differently from others. Patients with extra copies of MALT1 could be initially treated with H. pylori eradication,similar to patients without t(11;18) translocation or extra copies of MALT1.