Gastric Marginal Zone B-cell Lymphoma Research Articles

Clinical Impact Assessment and Utilization Prospects of the t(11:18) Chromosomal Translocation in Gastric MALT Lymphoma in Koreans: A Single Center Retrospective Analysis

The gastric extranodal marginal zone B-cell lymphomas of mucosa-associated lymphoid tissue (gastric MALT lymphoma) are mostly related to Helicobacter pylori infections. However, chromosomal aberration involving translocation t(11;18) is also frequently reported in these patients. The study was a retrospective review and analysis of electronic medical records to assess the factors which affect complete remission (CR) in patients with gastric MALT lymphoma. Based on the medical records, subjects with gastric MALT lymphoma were enrolled consecutively from January 2004 to December 2021. Among the 77 subjects who were found with gastric MALT lymphoma in the database, 65 cases with complete records were analyzed. Of these, 66.2% (43/65) were H. pylori positive. Genetic analyses for t(11:18) were done on 41 subjects. The t(11:18) chromosomal translocation with MALT1:BIRC3 fusion was found in 31.7% (13/41) of the subjects. With H. pylori eradication therapy, 75% (21/28) of the subjects without t(11:18) achieved CR. However, only 23.1% (3/13) subjects with t(11:18) could achieve CR (p-value= 0.009). In the H. pylori-positive group, 85.7% (18/21) subjects without t(11:18) achieved CR with eradication therapy, but 71.4% (5/7) subjects with t(11:18) failed to achieve CR (p-value=0.004). In the H. pylori-negative group, 42.3% (3/7) of the subjects without t(11:18) achieved CR with eradication therapy. However, 83.3% (5/6) of H. pylori-negative subjects with t(11:18) failed to achieve CR with eradication therapy and needed additional radiotherapy (p-value=0.396). H. pylori negativity and the presence of t(11:18) were both risk factors for failure to achieve CR with H. pylori eradication therapy as the first line of treatment.

Gastric marginal zone B-cell lymphoma of MALT type – An updated histo- and molecular pathological summary

Gastric marginal zone lymphoma (gMZBL) is the most frequent type of extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT). The histology of gMZBL shows typical small cell morphology, however, there also exists a large cell variant.

Rare case of gastric extranodal marginal zone lymphoma

True histiocytic lymphoma is considered a rare entity, and its diagnosis requires the concordance of morphological, immunophenotypic, and molecular findings. Gastric extra nodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) is a B-cell non-Hodgkin lymphoma that arises in the stomach and has a perifollicular/marginal zone growth pattern. The lymphoma is derived from marginal zone B-cells and recapitulates the architecture and organization of native MALT exemplified by the Peyers’ patches in the terminal ileum. Marginal zone lymphoma of MALT (MALT lymphoma) is the most common indolent subtype and represents 7% of all non-Hodgkin lymphomas.

Patients with Helicobacter pylori negative gastric marginal zone b-cell lymphoma (MZBCL) of MALT have a good prognosis

In current guidelines H. pylori eradication is recommended as first-line therapy in patients with gastric MALT lymphoma irrespective of stage and H. pylori status. However, data on treatment and clinical course of patients with H. pylori negative MALT lymphoma are rare. To evaluate therapeutical results in patients with H. pylori negative gastric MALT lymphoma. 21 patients (13 male and 8 female; 63.9 years, range 43 - 80) with gastric MALT lymphoma were analysed retrospectively on the basis of medical reports in all cases and repeated outpatient visits at our center in 17 cases. H. pylori infection was excluded by negative histology, rapid urease test, or C13 urease breath test, and serology in all cases. Follow-up was 56.4 (5 - 142) months. Ten of 21 patients were treated with H. pylori eradication, and four of them received no further therapy. The other six patients underwent surgery, chemotherapy, and radiation, after eradication therapy. Those eleven patients without H. pylori eradication received radiation (n = 3), chemotherapy (n = 1), PPIs (n = 2), no treatment (n = 4) as first-line and radiation (n = 2) as second-line therapy while initial therapy remained unknown in one case. 13 patients (61.9 %) reached complete remission of lymphoma, and seven patients (33.3 %) showed minimal histological residuals. Overall and disease-free survival was found in 95 % and 90 %, respectively. Patients with H. pylori negative gastric MALT lymphoma have a good prognosis. We favor initial H. pylori eradication therapy and a watch-and-wait strategy in case of minimal histological residuals of MALT lymphoma. Non-responders to eradication therapy can be successfully treated by radiation and chemotherapy.

Treatment of gastric marginal zone B‐cell lymphoma of the mucosa‐associated lymphoid tissue with rituximab, cyclophosphamide, vincristine and prednisone

There is no standard treatment for patients with gastric marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT lymphoma) who are resistant to, or ineligible for, anti-Helicobacter pylori (anti-HP) therapy. In this study, we investigated the activity of the rituximab, cyclophosphamide, vincristine and prednisone (R-CVP) regimen in patients with gastric MALT lymphoma. Patients were included provided they had untreated gastric MALT lymphoma (except for anti-HP therapy) and were resistant to, or ineligible for, anti-HP therapy. Treatment plan consisted of six to eight 21-day cycles of the R-CVP chemotherapy regimen. Toxicity, response, relapse and survival were evaluated. Twenty patients (12 women and 8 men) were included in the analyses with median age of 59 years. Thirteen patients (65%) had stage I tumours, and seven patients (35%) had stages II-IV tumours. The overall response rate was 100%, with 19 (95%) complete responses and one (5%) partial response. Regimen toxicity was mild and mainly hematological, and no cases of gastric bleeding or perforation occurred. After a median follow-up of 56.3 months, three patients had relapsed, and 19 patients remained alive (specific lymphoma survival 100%), of whom 17 had no evidence of disease. In our experience, the R-CVP regimen is a well-tolerated and effective treatment for patients with gastric MALT lymphoma who are resistant to, or ineligible for, anti-HP therapy.

Is There a Role for Capsule Endoscopy in the Staging Work-up of Patients with Gastric Marginal Zone B-cell Lymphoma of MALT?

In earlier studies, involvement of the small intestine was reported in patients with gastrointestinal lymphoma. Prospective data on the involvement of the small intestine in patients suffering from gastric extranodal MZBCL of MALT do not exist so far. In this study, we investigated the frequency of the involvement of the small intestine and the role of capsule endoscopy in patients with gastrointestinal extranodal MZBCL of MALT and of follicular lymphoma. 40 consecutive patients with gastrointestinal extranodal MZBCL of MALT (26 men, 14 women, aged 27 - 80 years), and 7 patients with known follicular lymphoma of the small intestine (5 men, 2 women, aged 34 - 63 years) underwent capsule endoscopy. Involvement of the small intestine was identified by capsule endoscopy in all 7 patients with known follicular lymphoma of the small intestine. In 6 of 40 patients with gastric extranodal MZBCL of MALT abnormal findings could be observed, three of these findings indicative for lymphoma involvement of the small intestine. However, in each of these 3 cases, intestinal involvement had been already diagnosed by conventional GI endoscopy before capsule endoscopy. Capsule endoscopy is able to detect involvement of the small intestine in patients with gastrointestinal lymphoma. However, involvement of the small intestine seems to be rare in patients with gastric extranodal MZBCL of MALT. In summary, routine diagnostic work-up of the small intestine, e. g. by capsule endoscopy seems unnecessary because of the rare involvement of the small intestine and an excellent long-term outcome irrespective of a possible intestinal manifestation.

Tu1085 Mantle Cell Lymphoma With Gastrointestinal Involvement: Characteristics and Clinical Outcome

Objective: Helicobacter pylori eradication has widely accepted as a primary treatment for gastric marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT). We evaluated long-term clinical outcome of low-grade gastric MALT lymphoma in a single center. Methods: From 1996 to 2010, a total of 205 H. pylori-infected patients with lowgrade gastric MALT lymphoma were prospectively enrolled in Seoul National University Hospital. Twelve patients were excluded due to presence of extra-gastric MALT lymphoma or other malignancy at initial diagnosis. Complete remission (CR) was defined as no endoscopic findings of lymphoma, and histopathology of complete histological response (ChR) or probable minimal residual disease (pMRD). Tumor response to H. pylori eradication therapy was evaluated by endoscopy and histopathology every 2-3 months till CR and every 6-12 months after achieving CR. Results: Median follow-up period was 5.4 years (range, 1.0-14.4 years). H. pylori was successfully eradicated in 187 (96.9%) of 193 eligible patients. CR was obtained in 170 (88.1%) patients and the median time to achieve CR was 3 months (range, 1-20 months) after H. pylori eradication therapy. Tumor recurrence was found in 7 (4.1%) patients and the median tumor recurrence time was 13 months (range, 3-61 months) after achieving CR. Cumulative recurrence rate was 1.9, 4.2 and 7.8% at 1, 3 and 5 years, respectively. Disease-free survival was 97.0, 96.1 and 94.8% at 3, 5 and 7 years, respectively. Other malignancies were found in 8 (4.1%) of 193 patients, none of whom had metachronous gastric cancer. Five-year and 10-year overall survival rate was 99.4 and 97.4%, respectively. Tumors of the proximal stomach (mid-body to fundus) (odds ratio [OR] 4.39, 95% confidence interval [CI] 1.34-14.43; p=0.015) and low serum total cholesterol level (,170 mg/dL) (OR 4.17, 95% CI 1.27-13.71; p=0.019) increased the risk of non-CR after H. pylori eradication therapy. Conclusions: Most patients with low-grade gastric MALT lymphoma treated by H. pylori eradication therapy showed excellent long-term outcomes. Serum total cholesterol might be a novel predictive marker for tumor response to H. pylori eradication therapy.

Tu1086 Management Strategy for Small Duodenal Carcinoid Tumors: Does Conservative Management With Close Follow-up Represent an Alternative to Endoscopic Treatment?

Objective: Helicobacter pylori eradication has widely accepted as a primary treatment for gastric marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT). We evaluated long-term clinical outcome of low-grade gastric MALT lymphoma in a single center. Methods: From 1996 to 2010, a total of 205 H. pylori-infected patients with lowgrade gastric MALT lymphoma were prospectively enrolled in Seoul National University Hospital. Twelve patients were excluded due to presence of extra-gastric MALT lymphoma or other malignancy at initial diagnosis. Complete remission (CR) was defined as no endoscopic findings of lymphoma, and histopathology of complete histological response (ChR) or probable minimal residual disease (pMRD). Tumor response to H. pylori eradication therapy was evaluated by endoscopy and histopathology every 2-3 months till CR and every 6-12 months after achieving CR. Results: Median follow-up period was 5.4 years (range, 1.0-14.4 years). H. pylori was successfully eradicated in 187 (96.9%) of 193 eligible patients. CR was obtained in 170 (88.1%) patients and the median time to achieve CR was 3 months (range, 1-20 months) after H. pylori eradication therapy. Tumor recurrence was found in 7 (4.1%) patients and the median tumor recurrence time was 13 months (range, 3-61 months) after achieving CR. Cumulative recurrence rate was 1.9, 4.2 and 7.8% at 1, 3 and 5 years, respectively. Disease-free survival was 97.0, 96.1 and 94.8% at 3, 5 and 7 years, respectively. Other malignancies were found in 8 (4.1%) of 193 patients, none of whom had metachronous gastric cancer. Five-year and 10-year overall survival rate was 99.4 and 97.4%, respectively. Tumors of the proximal stomach (mid-body to fundus) (odds ratio [OR] 4.39, 95% confidence interval [CI] 1.34-14.43; p=0.015) and low serum total cholesterol level (,170 mg/dL) (OR 4.17, 95% CI 1.27-13.71; p=0.019) increased the risk of non-CR after H. pylori eradication therapy. Conclusions: Most patients with low-grade gastric MALT lymphoma treated by H. pylori eradication therapy showed excellent long-term outcomes. Serum total cholesterol might be a novel predictive marker for tumor response to H. pylori eradication therapy.

Tu1084 Long-Term Outcome of Low-Grade Gastric Mucosa-Associated Lymphoid Tissue Lymphoma After Helicobacter pylori Eradication Therapy: A Prospective Single Center Study

Objective: Helicobacter pylori eradication has widely accepted as a primary treatment for gastric marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT). We evaluated long-term clinical outcome of low-grade gastric MALT lymphoma in a single center. Methods: From 1996 to 2010, a total of 205 H. pylori-infected patients with lowgrade gastric MALT lymphoma were prospectively enrolled in Seoul National University Hospital. Twelve patients were excluded due to presence of extra-gastric MALT lymphoma or other malignancy at initial diagnosis. Complete remission (CR) was defined as no endoscopic findings of lymphoma, and histopathology of complete histological response (ChR) or probable minimal residual disease (pMRD). Tumor response to H. pylori eradication therapy was evaluated by endoscopy and histopathology every 2-3 months till CR and every 6-12 months after achieving CR. Results: Median follow-up period was 5.4 years (range, 1.0-14.4 years). H. pylori was successfully eradicated in 187 (96.9%) of 193 eligible patients. CR was obtained in 170 (88.1%) patients and the median time to achieve CR was 3 months (range, 1-20 months) after H. pylori eradication therapy. Tumor recurrence was found in 7 (4.1%) patients and the median tumor recurrence time was 13 months (range, 3-61 months) after achieving CR. Cumulative recurrence rate was 1.9, 4.2 and 7.8% at 1, 3 and 5 years, respectively. Disease-free survival was 97.0, 96.1 and 94.8% at 3, 5 and 7 years, respectively. Other malignancies were found in 8 (4.1%) of 193 patients, none of whom had metachronous gastric cancer. Five-year and 10-year overall survival rate was 99.4 and 97.4%, respectively. Tumors of the proximal stomach (mid-body to fundus) (odds ratio [OR] 4.39, 95% confidence interval [CI] 1.34-14.43; p=0.015) and low serum total cholesterol level (,170 mg/dL) (OR 4.17, 95% CI 1.27-13.71; p=0.019) increased the risk of non-CR after H. pylori eradication therapy. Conclusions: Most patients with low-grade gastric MALT lymphoma treated by H. pylori eradication therapy showed excellent long-term outcomes. Serum total cholesterol might be a novel predictive marker for tumor response to H. pylori eradication therapy.

Treatment outcome of gastric extra-nodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue type in the Hong Kong Chinese population: a single centre experience.

To analyze the clinical characteristics, treatment outcome of patients with gastric extra-nodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue type (EMZBL-MALT). Data of 30 patients with gastric EMZBL-MALT diagnosed in Caritas Medical Center between July 1997 and June 2009 were analyzed retrospectively. The median follow-up time was 6.4 years [interquartile range (IQR) 3.9 to 8.9 years] and the median age at time of diagnosis was 71.5 years (IQR 64 to 81 years). All subjects, with investigations done for disease staging, suffered from localized disease (stage I or II1). Helicobacter infection was identified in 67% of subjects. Twenty Helicobacter-positive subjects received Helicobacter eradication treatment and seven Helicobacter-negative subjects received single-agent chemotherapy (cyclophosphamide), with disease remission rates at 85% and 71% respectively. Only one subject died apparently from disease progression. The 5-year and 10-year overall survival rates were 75% and 62.5% respectively. Helicobacter eradication and single-agent chemotherapy were effective treatment modalities for early stage gastric EMZBL-MALT with and without Helicobacter infection respectively. Survival was favorable.

Two Cases of Diffuse Large B-Cell Lymphomas in the Cervical Lymph Nodes in Patients with Low-Grade Gastric Marginal Zone B-Cell Lymphoma (MALT Lymphoma)

It is well known that gastric mucosa-associated lymphoid tissue (MALT) lymphomas are associated with Helicobacter pylori infection and have a good prognosis. However, although rare, these low-grade lymphomas transform to the high-grade diffuse large B-cell lymphomas (DLBCLs) which are thought to be the important cause of death in patients with MALT lymphoma. We report two cases of DLBCLs in the cervical lymph nodes that occurred 10 years and 1.5 years after diagnosing low-grade gastric MALT lymphomas.

Chlamydia psittaci-negative ocular adnexal marginal zone B-cell lymphomas have biased VH4-34 immunoglobulin gene expression and proliferate in a distinct inflammatory environment

Ocular adnexal marginal zone B-cell lymphomas (OAMZLs) arise in the connective tissues of the orbit or in the mucosa-associated lymphoid tissue of the conjunctiva. Here, we present the immunological and genetic analyses of 20 primary Chlamydia psittaci (Cp)-negative OAMZLs. Analysis of the immunoglobulin variable heavy chain (IgV(H)) gene usage demonstrated a significant preference for V(H)4-34. A combined analysis across all previously published OAMZLs confirmed that this is a general feature of OAMZL, in particular of the Cp-negative group. Our series of OAMZLs did not express the characteristic rheumatoid factor V(H)DJ(H) rearrangements that were previously found in salivary gland- and gastric-marginal zone B-cell lymphomas (MZBCLs). We did not detect the MZBCL-specific chromosomal translocations, t(11;18) API2-MALT1 (mucosa-associated lymphoid tissue1) and t(14;18) IgH/MALT1. Two cases contained a premature stop codon in the A20 gene (TNFAIP3) and one case harbored the activating MYD88 hotspot mutation L265P. Variable nuclear expression of BCL10, NFκB1 (p50) and NFκB2 (p52) suggests that other additional genetic abnormalities affecting the NFκB pathway exist within this group of lymphomas. OAMZL showed variable expression of the chemokine receptor CXCR3 and integrin α4β7 by the tumor B cells, and low interferon-γ and interlukin-4 mRNA levels in the tissue, indicative of an inflammatory environment with features in between those previously found in cutaneous and other extranodal MZBCL. The strongly biased usage of V(H)4-34 in Cp-negative OAMZLs suggests involvement of a particular stimulatory (auto-) antigen in their development.

The Determining Factors for Treatment Modality and the Results of Gastric Maginal Zone B-cell Lymphoma of Mucosa-Associated Lymphoid Tissue: Single Center Experience

Background/Aims: Though the gastric marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) of Lugano stage IE and IIE1 can often be turned into complete remission with antibiotics treatment, other treatment modalities including surgery and chemotherapy are employed in some cases. The purpose of this study was to evaluate the determining factors for treatment modality and the result of the different treatment modalities. Materials and Methods: We reviewed the medical records of patients diagnosed with gastric MALT lymphoma in Yeoido St. Mary’s Hospital from March 2002 to Feb 2010. Results: All 16 patients were diagnosed with gastric MALT lymphoma at stage IE and IIE1. Three patients received chemotherapy with cyclophosphamide, adriamycin, vincristine, prednisolone (CHOP) regimen, 3 patients underwent surgery and the other 10 patients received antibiotics only. All patients achieved complete remission within 5.1±5.1 months and remained stable for 34.8±17.6 months. There were no difference in oncologic outcome between the treatment modalities. The positivity of Helicobacter pylori (H. pylori) infection and the gastroenterology specialty of physician in charge lead to antibiotics treatment rather than other modalities (P<0.05). Conclusions: The H. pylori infection status and the specialty of the physician in charge were the meaningful determining factors for treatment modalities. (Korean J Helicobacter Up Gastrointest Res 2012;12:27-33)

Two Cases of Gastric MALT Lymphoma Diagnosed at Long Last after Successful Eradication ofHelicobacter pylori

The gastric marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) is a rare disease. Helicobacter pylori infection is known as an important etiologic factor of the pathogenesis of MALT lymphoma. H. pylori colonization at the epithelium of gastric mucosa induces T cell and B cell recruitment. T cell induced B cell proliferation develops the MALT in the gastric mucosa. Monoclonal proliferation of B cell in the MALT transform into MALT lymphoma. The eradication of H. pylori is known to induce remission of the disease in more than 80% of patients. But there is no report on progression and development of MALT lymphoma after H. pylori eradication. We experienced two cases of gastric B cell MALT lymphoma diagnosed at long last, after the successful eradication of H. pylori. (Korean J Helicobacter Up Gastrointest Res 2012;12:265-270)

Role of Chemotherapy in Gastric Marginal Zone B-Cell Lymphoma of Mucosa-Associated Lymphoid Tissue (MALT) Type

Correspondence to Yong Park, M.D., Ph.D. Division of Hematology/Oncology, Department of Internal Medicine, Korea University College of Medical College, 73 Inchon-ro, Seongbuk-gu, Seoul 136-705, Korea Tel: +82-2-920-6847, Fax: +82-2-920-5982, E-mail: paark76@hanmail.net Copyrightc 2012 The Korean Association of Internal Medicine This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original work is properly cited. 위말트림프종의 항암치료

WHO Classification of Malignant Lymphomas in Korea: Report of the Third Nationwide Study

Background: The aim of study was to determine the relative frequency of malignant lymphoma according to World Health Organization (WHO) classification in Korea. Methods: A total of 3,998 cases diagnosed at 31 institutes between 2005 and 2006 were enrolled. Information including age, gender, pathologic diagnosis, site of involvement and immunophenotypes were obtained. Results: The relative frequency of non-Hodgkin lymphoma (NHL) and Hodgkin lymphoma (HL) was 95.4% and 4.6%, respectively. B-cell lymphomas accounted for 77.6% of all NHL, while T/ natural killer (T/NK)-cell lymphomas accounted for 22.4%. The most frequent subtypes of NHL were diffuse large B-cell lymphoma (42.7%), extranodal marginal zone B-cell lymphoma (MZBCL) of mucosa-associated lymphoid tissue (19.0%), NK/T-cell lymphoma (6.3%) and peripheral T-cell lymphoma (PTCL), unspecified (6.3%), in decreasing order. The relative frequency of HL was no dular sclerosis (47.4%), mixed cellularity (30.6%), and nodular lymphocyte predominant (12.1%) subtypes. Compared with a previous study in 1998, increase in gastric MZBCL and nodular sclerosis HL, and slight decrease of follicular lymphoma, PTCL, and NK/T-cell lymphoma were observed. Conclusions: Korea had lower rates of HL and follicular lymphoma, and higher rates of extranodal NHL, extranodal MZBCL, and NK/T-cell lymphoma of nasal type compared with Western countries. Changes in the relative frequency of lymphoma subtypes are likely ascribed to refined diagnostic criteria and a change in national health care policy.

Long-term outcome following Helicobacter pylori eradication in a retrospective study of 105 patients with localized gastric marginal zone B-cell lymphoma of MALT type

Background: Treatment aimed at eradicating Helicobacter pylori infection results in lymphoma remission in most localized gastric mucosa-associated lymphoid tissue (MALT) lymphomas. The aim of this survey is to investigate the long-term effect of this therapeutic approach in a large series of patients.Methods: One hundred and five patients with localized gastric MALT lymphoma were initially treated only with H. pylori eradication regimens. Lymphoma responses were graded using the Wotherspoon score.Results:Helicobacter pylori, detected by histology in 81% of cases, was eradicated in all positive patients. Histological regression of the lymphoma was achieved in 78 of 102 assessable patients [76%, 95% confidence interval (CI): 67% to 84%] with complete remission (score 0–2) in 66 and partial remission (score 3) in 12. At a median follow-up time of 6.3 years, histological remission was consistently confirmed in 33 of 74 assessable patients, while 25 had score fluctuations (from 0 to 4) and 13 presented a lymphoma relapse (score 5). Only one patient had a distant progression. Transformation to a large-cell lymphoma was seen in two cases. The 5- and 10-year overall survival is 92% (95% CI: 84% to 96%) and 83% (95% CI: 70% to 91%), respectively. Only one patient died of lymphoma after transformation to a high-grade lymphoma.Conclusions:Helicobacter pylori eradication resulted in complete lymphoma remission in the majority of cases. Long-term clinical disease control was achieved in most patients. A watch and wait policy appears to be safe in patients with minimal residual disease or histological-only local relapse.

Methylation of p16INK4A and Mitotic Arrest Defective Protein 2 (MAD2) Genes in Gastric Marginal-Zone B-Cell Lymphomas

Background: Products of cyclin-dependent kinase inhibitor p16^INK4Aand mitotic arrest defective protein 2 (MAD2) genesare key regulator proteins at the G1 restriction point and mitotic checkpoint of the cell cycle. The objective of this study was to investigate the role of promoter methylation of p16^INK4A and MAD2 genes in gastric marginal-zone B-cell lymphoma (MZBCL). Materials and Methods: Gastric biopsies from 40 patients were analyzed by methylation-specific polymerase chain reaction, and the methylation status was compared with the results of BCL10 expression and t(11;18)(q21;q21) translocation. Results and Conclusion:p16^INK4A was methylated in 30 of 40 MZBCLs (75%). The lymphomas with p16^INK4A methylation tended to be negative for t(11;18)(q21;q21) (p = 0.011). MAD2 gene was methylated in 23 of 38 MZBCLs (61%). Lymphomas with MAD2 gene methylation more frequently expressed BCL10 (p = 0.037). These methylation profiles suggest that p16^INK4A and MAD2 gene may play a role in the pathogenesis of MZBCL via different pathways; MAD2 gene is Helicobacter pylori independent with a close association with BCL10 while p16^INK4A is H. pylori dependent with an inverse correlation with the t(11;18)(q21;q21) translocation.

Clinicopathological comparison of the World Health Organization/Wotherspoon score to the Groupe d’Etude des Lymphomes de l’Adult grade for the post‐treatment evaluation of gastric mucosa‐associated lymphoid tissue lymphoma

The World Health Organization (WHO) has adopted criteria for the histological differential diagnosis of gastric extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (GML) based on the criteria proposed by Wotherspoon in 1993 (WHO/Wotherspoon score). These histological criteria are commonly used by pathologists for initial diagnoses, but have not been adopted uniformly for the post-treatment evaluation of GML. In 2003, the Groupe d'Etude des Lymphomes de l'Adult (GELA) proposed a new histological grading system (GELA grade) in preference to use of the WHO/Wotherspoon score for post-treatment evaluation. In the present study, we compared the WHO/Wotherspoon and GELA systems to examine which histological criterion is better for post-treatment evaluation. Fourteen cases of GML under long-term follow up were initially diagnosed according to the WHO criteria with detailed immunohistology, and were periodically evaluated with both histological criteria after anti-Helicobacter pylori treatment. They were also evaluated based on histological stromal changes accompanying the disappearance of lymphoma tissue. The study showed strong similarities between the WHO/Wotherspoon and GELA systems and no clear advantage of either system for post-treatment evaluation. The GELA grade could not be used for the evaluation of changes in the degree of lymphoma infiltration from pre- to post-treatment because the four-item scale is not comparable with the formal six-point WHO/Wotherspoon scale. Stromal changes in the lamina propria, including an empty appearance and fibrosis, were correlated with lymphoma reduction after treatment and appear to be good indicators for post-treatment evaluation. We propose the utilization of the WHO/Wotherspoon score accompanied by the assessment of stromal changes for the post-treatment evaluation of GML.

T(11;18)(q21;q21) in extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue in stomach: a study of 48 cases

Gastric extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MZL-MALT) is speculated to be immune mediated and is notable for responding to treatment by Helicobacter pylori eradication. However, the gastric MZL-MALT with t(11;18)(q21;q21) has been shown to be resistant to treatment by H. pylori eradication. We studied the molecular, immunohistochemical, and histological aspects of 48 cases of gastric MZL-MALT and used a reverse transcription real-time PCR assay to assess the presence of a t(11;18)(q21;q21) in formalin-fixed, paraffin-embedded tissue. Florescence in situ hybridization for t(11:18)(q21;q21) was used to confirm the real-time PCR results. Three distinct morphological subtypes were recognized: monocytoid, small lymphocytic, and plasmacytoid. Morphology, immunophenotype, and immunoglobulin heavy chain (IgH) gene rearrangement were correlated with the results of the t(11:18)(q21;q21) assay. Of the 48 analyzed cases, 15 (31%) were positive for t(11;18)(q21;q21) and 33 (69%) were monoclonal for IgH gene rearrangement. Of the 15, 13 (87%) cases with t(11;18)(q21;q21) translocation showed IgH gene rearrangement by PCR. Of the 33 t(11;18)(q21;q21)-negative cases tested, 20 cases (61%) showed IgH gene rearrangement. The 15 t(11;18)(q21;q21) translocation-positive cases had either monocytoid (12 of 15) or small lymphocytic morphology (3 of 15). Aberrant expression of CD43 was observed in 8 of 15 (53%) t(11;18)(q21;q21)-positive cases and 21 of 31 (68%) t(11;18)(q21;q21)-negative cases. Our data show that t(11;18)(q21;q21)-positive MZL-MALTs frequently show monocytoid morphology, less often small lymphocytic morphology, and not purely plasmacytoid morphology. Identification of a t(11;18)(q21;q21) by reverse transcription real-time PCR is highly specific for MZL-MALT and helps in the diagnosis of MZL-MALT. Studying the correlation between this translocation and morphological features may increase our understanding of the role of this translocation in the pathogenesis and the clinical behavior of gastric MZL-MALT.