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.

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.

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.

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.

Clinical outcomes of radiation therapy for early-stage gastric mucosa-associated lymphoid tissue lymphoma

AIM:To evaluate the clinical outcomes of radiation therapy(RT)for early-stage gastric mucosa-associated lymphoid tissue lymphoma(MALToma).METHODS:The records of 64 patients treated between 1998 and 2011 were analyzed retrospectively.For Helicobacter pylori(H.pylori)-positive patients(n=31),chemotherapy or H.pylori eradication therapy was the initial treatment.In patients with failure after H.pylori eradication,RT was performed.For H.pylorinegative patients(n=33),chemotherapy or RT was the first-line treatment.The median RT dose was 36Gy.The target volume included the entire stomach andthe perigastric lymph node area.RESULTS:All of the patients completed RT without interruption and showed complete remission on endoscopic biopsy after treatment.Over a median follow-up period of 39 mo,the 5-year local control rate was 89%.Salvage therapy was successful in all relapsed patients.Secondary malignancies developed in three patients.The 5-year overall survival rate was 94%.No patient presented symptoms of moderate-to-severe treatmentrelated toxicities during or after RT.CONCLUSION:Radiotherapy results in favorable clinical outcomes in patients with early-stage gastric MALToma who experience failure of H.pylori eradication therapy and those who are H.pylori negative.

Radiotherapy for gastric mucosa-associated lymphoid tissue lymphoma

Gastric mucosa-associated lymphoid tissue(MALT)lymphoma is a rare disease which is often associated with Helicobacter pylori(H.pylori)infection.First-line treatment of stage IE and IIE localized gastric MALT lymphoma is based on the eradication of H.pylori.The presence of H.pylori resistance factors such as translocation t(11;18),peri-gastric lymph node involvement and the degree of tumor infiltration of the gastric wall;or lack of response to antibiotic therapy are two main indications to treat with definitive radiotherapy(RT).RT is an effective treatment in localized gastric MALT lymphoma.A moderate dose of 30 Gy allows a high cure rate while being well tolerated.After treatment,regular gastric endoscopic follow-up is necessary to detect a potential occurrence of gastric adenocarcinoma.

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.

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.

Remission of primary low-grade gastric lymphomas of the mucosa-associated lymphoid tissue type in immunocompromised pediatric patients

我们报导联系 mucosa 的淋巴组织(麦芽) 的主要胃的淋巴瘤的宽恕在二免疫打损害小儿科的病人。病人 1，在免疫的一个 14 岁的男孩损害了未知原因的状态，抱怨了重复腹的疼痛。考试与本地侵略和淋巴节点参与揭示了胃的麦芽。浆液 anti-Helicobacter pylori (H pylori ) 抗体是积极的。H pylori 根除被沉溺于它的不利效果。麦芽损害自发地在没有为淋巴瘤的任何治疗的下一 24 个月的 regressed。病人 2，一个 6 岁的男孩，为 adrenoleukodystrophy 的治疗经历了脐带血移植。他是为在移植以后的 graft-versus-host 疾病的管理抑制免疫力的药。恶心和便血出现了，进一步的考试与 H pylori 胃炎揭示了胃的麦芽。独自为 H pylori 感染由药组成的治疗根除了 H pylori 并且完全也解决了病人的麦芽损害。病人们 1 和 2 被跟随在上面在 10 年和 3 年的经期上，分别地没有恶化的任何症状。在结论， MALT 类型的胃的淋巴瘤能被保守疗法甚至在免疫治好损害小儿科的病人。

Detection of apoptotic cells and immunohistochemical study of bcl-2 and p53 gene protein in primary gastric mucosa-associated lymphoid tissue (MALT) lymphoma

To identify the apoptotic cells in gastric MALT lymphoma and its relationship between bcl-2 and p53 gene expression. Methods: TdT-mediated dUTP biotin Nick End labeling (TUNEL) and immuno-histochemistry ABC method were used to display apoptotic cells and the gene protein expression of bcl-2 and p53 independently. Results: Apoptotic indices (AI) in high-grade MALT lymphomas were significantly higher than in mixed-grade group and low-grade group (P<0.05). Bcl-2 was expressed in 83% of low-grade tumors, 61.6% of the median-grade tumors and 43.7% of high-grade tumors. An inverse correlation was observed between the expression of bcl-2 and apoptotic indices. Only 27 cases were p53 positive. The frequency of p53 positivity was significantly increased as the histologic grade advanced (P<0.05). There was also an inverse correlation between the expression of bcl-2 and p53. Conclusion: Apoptosis may be important in tumors development and transmission. p53 and bcl-2 were important regulatory genes of apoptosis and may be associated with transformation from low- grade to high-grade lymphomas.

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.

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.

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.

Clinical features and treatment outcomes of primary ocular adnexal mucosa-associated lymphoid tissue lymphoma: a single center retrospective analysis of 64 patients in China

AIM: To investigate the clinical features, treatment and prognosis of primary ocular adnexal mucosa-associated lymphoid tissue lymphoma(POAML).METHODS: A retrospective analysis was performed on 64 patients with POAML who were admitted to the First Affiliated Hospital of Zhengzhou University from January 2006 to December 2018.RESULTS: With a median follow-up of 61 mo(range, 2-156 mo), estimated overall survival(OS) rate and progressionfree survival(PFS) rate at 10 y reached 94.5% and 61.5%, respectively. Median OS time and PFS time were not reached. During this period, only 3 patients died, but none of them died directly due to disease progression. One patient(1.6%) developed transformation to diffuse large B-cell lymphoma(DLBCL). Of the 56 patients achieved complete remission after first-line treatment, 5(8.9%) developed local and/or systemic relapse eventually. Patients ≥60 y had significantly shorter PFS than younger patients(P=0.01). For patients with early stages(Ann Arbor stage I and stage II), univariate analysis confirmed that radiotherapydose lower than 32 Gy were independently associated with shorter PFS(P=0.04). Other factors including gender, bone marrow involvement, the initial location of the disease, and the laterality were not associated with PFS.CONCLUSION: The data from our center indicate that POAML has a slow clinical progression and has an excellent clinical outcome. Patients with POAML harbor a continual risk of relaps and transformation to aggressive subtype of lymphoma.

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.

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.