Regression of gastric high grade mucosa associated lymphoid tissue (MALT) lymphoma after Helicobacter pylori eradication

BACKGROUND: Most low grade gastric lymphomas arising from the mucosa associated lymphoid tissue (MALT) are related to Helicobacter pylori colonisation. Cases with disease limited to the stomach can be cured after H pylori eradication and remain in remission for years. In contrast, high grade lymphomas of the stomach, although also related to H pylori, do not usually respond to eradication treatment. CASE REPORT: A 36 year old patient was referred from another hospital with a diagnosis of a low grade gastric MALT lymphoma associated with H pylori. The patient was in stage I and while waiting for the biopsies to be reviewed H pylori eradication therapy was given as the first step of treatment. Review of the biopsies showed a high grade immunoblastic lymphoma with areas of low grade gastric MALT lymphoma (high grade gastric MALT lymphoma or diffuse large B cell lymphoma with areas of MALT type lymphoma of the WHO classification). The patient received no further treatment but has been closely followed up for 32 months with sequential endoscopies to obtain biopsies for histological studies, H pylori cultures, and polymerase chain reaction analysis of the IgH gene. RESULTS: After H pylori eradication the patient had a complete histological response that has been maintained for 32 months. Monoclonal IgH gene rearrangement persisted for 32 months. CONCLUSION: The response of this patient indicates the possibility that some cases of high grade gastric MALT lymphoma (possibly patients in stage I with a superficial or limited disease) may still be responsive to H pylori antigenic drive and may be cured with eradication therapy. Prospective studies should be performed to identify patients with high grade gastric MALT lymphomas that may respond to eradication therapy and be spared of other more aggressive treatments.     

Primary lymphomas in the gastrointestinal tract

Primary gastrointestinal (GI) lymphomas are uncommon diseases that can involve the whole GI tract. The etiologies of the disease remain unclear, and potential risk factors include celiac disease, Helicobacter pylori infection, use of immunosuppressive agents, human immunodeficiency virus (HIV) or Epstein–Barr virus (EBV) infection and inflammatory bowel disease, etc. Diffuse large B‐cell lymphoma (DLBCL) and mucosa‐associated lymphoid tissue (MALT) lymphoma are the most common subtypes of GI lymphomas. B‐cell lymphomas of the GI tract are more common in Western countries, while in Asia–Pacific region T‐cell lymphomas are more frequently reported. In this review, lymphomas in the esophagus, stomach and intestine are described, including their epidemiology, histology, clinical manifestations, endoscopic findings, radiological features and treatment.     

Treatment and survival of 38 female breast lymphomas: a population-based study with clinical and pathological reviews

Breast lymphomas are rare and consensus about their treatment is lacking. A population-based study of 38 breast lymphomas, registered in the databases of two Comprehensive Dutch Cancer Centers from 1981 to 1999, was performed. The median age of all female patients was 65 years (20-92): 25 patients had localized and 13 patients had disseminated lymphoma. The most common type was diffuse large B-cell lymphoma (DLBCL), which accounted for 17 of the localized and 4 of the disseminated cases. Burkitt's lymphoma (BL), three being disseminated, was found in four patients. There were six extranodal marginal zone lymphomas (ENMZL), three being localized. Seven DLBCL and one BL showed additional histological features of mucosa-associated lymphoid tissue (MALT) lymphoma. Localized aggressive lymphomas treated with surgery and/or radiation therapy had relapse rates of 100% and 67%, respectively. Cyclophosphamide, hydroxydaunomycin, vincristine, and prednisone (CHOP)-like chemotherapy with or without local irradiation led to 17% relapses in patients with localized aggressive lymphoma. Median follow-up time was 32 months (0.6-218); 37% of the patients relapsed and 24% had progressive disease. Response to salvage regimens, given to 91% of the patients with recurrent disease, was poor. The 2-year overall survival rate was 63%, 72% for patients with localized disease, and 46% for patients with disseminated lymphoma. The majority of breast lymphomas are localized aggressive lymphomas that should be treated initially with CHOP-like chemotherapy with or without irradiation. The initial choice of treatment is very important because response to salvage regimens is poor.     

Clinicopathological features of gastric mucosa-associated lymphoid tissue lymphoma: A comparison with diffuse large B-cell lymphoma without a mucosa-associated lymphoid tissue lymphoma component

BACKGROUND AND AIMS: The aim of this study was to clinicopathologically distinguish the pathogenesis of gastric mucosa-associated lymphoid tissue (MALT) lymphoma and diffuse large B-cell lymphoma without a MALT lymphoma component (DLL). METHODS: We investigated clinicopathological features of these gastric lymphomas including age, sex ratio, tumor location and depth, macroscopic appearance, and infection with Helicobacter pylori of these gastric lymphomas and hepatitis viruses in 24 patients with gastric low-grade MALT lymphoma, 10 patients with high-grade MALT lymphoma, and 19 patients with DLL. The frequency of H. pylori infection in lymphoma patients was compared with that in age- and sex-matched control subjects. RESULTS: There was a predominance of females with MALT lymphoma (male to female ratio, 8/16 for low-grade MALT lymphomas and 1/9 for high-grade MALT lymphomas), and there was a predominance of males with DLL (male to female ratio, 13/6); the ratios differed significantly (P < 0.05). Ninety-two percent of low-grade MALT lymphomas and 80% of high-grade MALT lymphomas were confined to the mucosal and submucosal layers, but lymphoma cells invaded the muscular layer or more deeply in 74% of DLL. Helicobacter pylori infection occurred significantly more often in patients with low-grade MALT lymphoma than in age- and sex-matched controls (96 vs 67%, P < 0.01). Conversely, the frequency of H. pylori infection in DLL patients did not differ from that in controls. CONCLUSIONS: These data suggest that H. pylori infection may be associated with the development of gastric MALT lymphoma, but not DLL, and that MALT lymphoma and DLL may have a different pathogenesis.     

Non-Hodgkin's lymphomas in Greece according to the WHO classification of lymphoid neoplasms. A retrospective analysis of 810 cases

The purpose of this retrospective study, the largest unselected series in our country, was to illustrate the clinicopathological features of non-Hodgkin's lymphoma (NHL) classified according to the World Health Organization (WHO) classification of lymphoid neoplasms. A retrospective analysis was conducted and clinical features of histological subtypes were established in 810 patients (age > or = 15 years) with NHL who were treated at 8 major centers representative of Greece. There were 435 males and 375 females 95% of them aged >30 years. B symptoms were present in 34% of the patients, while 45.3% had stages I-II and 54.6% had stages III-IV. LDH was increased in 37% of the patients. B cell lymphomas formed 88% of the cases whereas T cell lymphomas formed 12% of the total. Indolent lymphomas accounted for 31.1%, aggressive ones for 66.7% and very aggressive ones for 2.4% of all NHLs. Among indolent lymphomas extranodal ones (MALT B cell lymphoma) were the most common subset while follicular lymphoma grade I and II and small lymphocytic ones presented with equal frequency. Among the aggressive lymphomas diffuse large cell lymphoma (DLCL) was the most common subtype; this entity along with large-cell immunoblastic lymphomas accounted for 45.2% of all B cell lymphomas. Among the T cell lymphomas, peripheral T cell lymphomas and anaplastic large cell lymphomas of the T/null-cell type were the most common subtypes. The most common extranodal presentation was the gastrointestinal tract (GI). Next in frequency were primary extranodal NHL of the head and neck region. MALT B cell lymphomas were found in almost half of the patients with GI tract NHL, whereas in all other extranodal places DLCL was the predominant histological subtype. The median survival for indolent and aggressive NHL was 123.5 and 55.5 months, respectively. This is the first report of a large series of malignant lymphomas in Greece using the WHO classification. It appears that there are no significant differences between NHL in Greece and other large series as far as clinical and extranodal presentation is concerned. The frequency of follicular lymphoma in the current study is comparable to that reported from Asian countries and mainland Europe, but lower than that of US and Northern European series. There were no important differences in the incidence of the remaining histological subtypes between Greece and other European countries.     

Subcutaneous dissemination pattern in extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue lymphoma

Background

Mucosa-associated lymphoid tissue (MALT) lymphoma is among the most common forms of extranodal lymphomas, but little is known about subcutaneous involvement in patients with non-primary cutaneous marginal zone lymphomas.

Design and Methods

Patients with MALT lymphoma diagnosed and treated at our institution between 1999 and 2010 were analyzed for subcutaneous deposits from MALT lymphoma diagnosed in another organ. Histological, clinical and genetic findings were assessed.

Results

Among 216 patients with MALT lymphoma, 12 had subcutaneous deposits from MALT lymphoma (5.5%). In two patients, these lesions were present at diagnosis, while they constituted the site of relapse at an interval between 5 to 144 months in the remaining cases. Interestingly, nine of the 12 patients with subcutaneous deposits had originally been diagnosed with MALT lymphoma of the ocular adnexa (total number=51; 20%), and the other three had MALT lymphoma in the breast (total number=5; 60%). None of the patients with gastric (n=86), salivary gland (n=32) or pulmonary (n=19) MALT lymphomas had subcutaneous involvement during a median follow-up time of 87 months (range; 4 to 119 months).

Conclusions

Our data show that subcutaneous MALT lymphoma involvement is a rare event in patients with prior non-cutaneous extranodal marginal zone lymphoma. However, it seems to be almost exclusively associated with MALT lymphoma of the ocular adnexa and the breast, suggesting as yet undefined interactions between potentially embryonically related organ systems.     

Prim?re Lymphome des Gastrointestinaltrakts

Primary lymphomas of the gastrointestinal tract comprise different entities. Indolent marginal zone B-cell lymphoma of MALT (MALT lymphoma) and aggressive diffuse large cell B-cell lymphoma (DLBCL) represent the most common gastric lymphomas. In the small intestine, enteropathy associated T-cell lymphomas (EATCL) are of some importance. Diagnosis of gastrointestinal lymphoma is based on histological and immunohistochemical characteristics. Once the diagnosis of lymphoma is established various staging procedures are necessary to determine the stage of the lymphoma. Therapy of most gastrointestinal lymphomas has a curative intention. Surgery no longer plays a role in this context. Considering the pathogenetic importance of H.?pylori for gastric MALT lymphoma eradication of the bacteria is the treatment of first choice. For non-responders radiation and chemotherapy are good candidates. Immunochemotherapy with rituximab and CHOP offer a curative therapeutic attempt in DLBCL of the stomach and small intestine. There is no established therapy for EATCL which is characterized by a bad prognosis. Follicular lymphomas grade I/II of the duodenum and small intestine reveal an indolent course of disease and often do not require any oncological therapy.     

Bilateral breast MALT lymphoma: a case report and review of the literature

 Breast lymphoma is a rare disease. Both primary and secondary breast involvement have been reported. Most primary breast lymphomas are high-grade malignant neoplasms, mainly large cell and Burkitt type. Low-grade lymphomas of the breast, particularly mucosa-associated lymphoid tissue (MALT) lymphomas, have been exceedingly rare. In this report we present a patient with bilateral breast involvement by MALT lymphoma. Our patient developed localized MALT lymphoma in both breasts in a sequential fashion. She was treated with bilateral lumpectomy, followed by radiation therapy to both breasts. The patient is alive and well more than 1 year after therapy with no recurrence. We believe this is the first such case described in detail in the literature. Received: March 10, 1999 / Accepted: July 6, 1999     

Prognosis and outcome of non-Hodgkin lymphoma in primary Sjögren syndrome

Sj?gren syndrome (SS) has been associated with the development of non-Hodgkin lymphoma (NHL). From a cohort of 584 SS patients followed in our department from 1980 to 2010, we retrospectively analyzed 53 consecutive NHL cases. Considerations included histologic type, clinical manifestation and NHL staging, treatment, response rate and overall survival (OS), event-free survival (EFS), and standardized mortality ratio (SMR).Mucosa-associated lymphoid tissue (MALT) lymphomas constituted the majority (59%) of NHL subtypes, followed by nodal marginal zone lymphomas (NMZLs) (15%) and diffuse large B-cell lymphomas (DLBCLs) (15%). Six lymphoma patients died during the median follow-up of 40.8 months. The corresponding age/sex-adjusted SMR of SS with and without NHLs versus the general population was 3.25 (95% confidence interval [CI] 1.32-6.76) and 1.08 (95% CI, 0.79-1.45), respectively. A "watch and wait" policy was adopted for 9 patients with asymptomatic localized salivary MALT lymphomas. Eight patients with limited-stage MALT lymphomas and extraglandular manifestations were treated with rituximab. Ten MALT lymphoma patients with disseminated disease received chemotherapy with or without rituximab. The 3-year OS and EFS in patients with MALT lymphomas was 97% and 78%, respectively. Rituximab plus CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) was the chosen therapeutic intervention for patients with DLBCLs. A successful outcome was recorded for this group, with 100% OS and EFS at 3 years. Patients with NMZLs had a less favorable outcome, with a 3-year OS of 80% and EFS of 53%. Our results describe the course and prognosis of SS-associated NHL and highlight the need for a risk-stratified treatment approach.     

Primary salivary gland lymphoma: a clinicopathologic study of 23 cases in Taiwan

Twenty-three patients with primary salivary gland lymphoma were diagnosed between 1990 and 2001. The sites of involvement were the parotid gland in 13, the submandibular gland in 9 and the minor salivary gland in 1. The sites of lymphoma involvement beyond the salivary glands were the cervical lymph nodes in 7, bone marrow in 3, the axillary lymph nodes in 3, the nasopharynx in 2, the abdominal lymph nodes in 2, the palate, the subconjunctiva, and the spleen in 1 each patient. Histologically, 19 patients had lymphomas of mucosa-associated lymphoid tissue (MALT) with myoepithelial sialadenitis in 13, 3 patients had diffuse large cell lymphomas and 1 had follicular lymphoma. Six patients were in stage I, 4 in II, 1 in III and 12 in IV. Eight of 23 patients (35%) had autoimmune diseases before or after the diagnosis of NHL and all suffered from MALT lymphoma. Four patients with parotid MALT lymphoma had primary or secondary Sjogren's syndrome. One each patient suffered from hyperthyroidism, systemic lupus erythematosus, membranoproliferative glomerulonephritis and cryoglobulinemia, respectively. All the 6 stage I patients had achieved complete remission (CR) without relapses 17-84 months (median 44 months) after treatment. Excluding a stage IV patient with follicular lymphoma who died at 3.5 months without treatment, CR was achieved in all of the remaining 16 patients. However, a high relapse rate (9/16, 56%) was noted in stage II-IV patients. These patients tended to relapse in the original sites, but achieved CR again after chemotherapy or radiotherapy. One patient with MALT lymphoma developed histologic transformation into diffuse large lymphoma during relapse and died of refractory disease. Overall, only 2 patients succumbed. The overall survival and relapse-free survival rates at 5 years were 94.7 and 51.4%, respectively. Thus, salivary gland lymphoma proved to be an indolent disease.     

Clinical features and prognosis of gastric MALT lymphoma with special reference to responsiveness to H. pylori eradication and API2-MALT1 status

BACKGROUND AND AIM: Clinicopathologic characteristics and prognosis of Helicobacter pylori eradication-resistant gastric MALT lymphoma have not been well clarified. We analyzed a consecutive series of gastric MALT lymphomas at our institution regarding treatment, clinical course, and prognosis, with special reference to responsiveness to H. pylori eradication and presence of API2-MALT1. METHODS: Subjects were 92 consecutive patients with gastric MALT lymphoma. Seventy were H. pylori positive, and 87 received H. pylori eradication therapy. The remaining five cases were API2-MALT1 positive and did not receive eradication treatment. Second-line treatments were radiation therapy, total gastrectomy, and chemotherapy (rituximab, rituximab plus CHOP, or rituximab plus 2-chlorodeoxyadenosine). RESULTS: Gastric MALT lymphoma was classified into three groups, except one case with API2-MALT1 who responded to H. pylori eradication therapy: responders without API2-MALT1 (group A, N = 56, 65%), nonresponders without API2-MALT1 (group B, N = 16, 19%), and nonresponders with API2-MALT1 (group C, N = 14, 16%). Most cases in group A attained complete remission (CR) in 2 or 3 months and CR persisted for an average of 51.1 months (3-134 months). Recurrence was only seen in one case. In groups B and C, radiation therapy, chemotherapy, and total gastrectomy resulted in CR in 13, 5, and 2 cases, respectively. In 5 group B patients and 6 group C patients who did not undergo second-line therapy, disease did not progress for an average of 10.4 and 40.1 months, respectively. In 1 group C case who did not receive second-line treatment, lymphoma metastasized to the lung 12 yr after eradication. All group B patients and all but 2 group C patients remain alive; one of these deaths was from gastric carcinoma developing 7 yr after eradication. CONCLUSION: Gastric MALT lymphoma responding to H. pylori eradication demonstrated good prognosis, and for nonresponsive cases, second-line treatments resulted in CR. However, careful observation for development of gastric carcinoma and disease progression is essential during follow-up of API2-MALT1-positive MALT lymphoma when patients decline second-line treatment.     

Rituximab retherapy in patients with relapsed aggressive B cell and mantle cell lymphoma

Neither effective salvage regimens nor the outcome and response to retherapy with rituximab containing chemotherapy have been defined for rituximab pre-treated patients with relapsing aggressive lymphoma. We report here a single-centre retrospective outcome analysis of second-line immunochemotherapy with rituximab. In 28 patients with relapsed or refractory diffuse large B cell lymphomas, first-line immunochemotherapy had induced objective responses in 18 patients. Nine of 28 patients responded to rituximab containing salvage therapy, leading to a median overall survival of 243 days after start of second immunochemotherapy. Long-term disease free survivors (1,260 and 949 days) were restricted to the group of twelve patients that had received allogeneic stem cell transplantation as consolidation therapy. In 21 patients with relapsed mantle cell lymphomas (MCL), 19 patients had reached remissions with first-line therapy. Of those, 16 patients experienced responses to salvage therapy with a median overall survival of 226 days. Noteworthy, none of patients with initial non-responding disease reached a remission with second immunochemotherapy. Seven patients with MCL stayed free from progression after high-dose therapy with autologous or allogeneic stem cell transplantation in two and five cases, respectively. In summary, responses to repeated immunotherapy with rituximab were observed in approximately one third and two thirds of initially responding patients with aggressive B cell lymphoma and mantle cell lymphoma, respectively, but not in primarily refractory disease. Lasting remissions were achieved only by high-dose chemotherapy with stem cell transplantation.     

2-Chlorodeoxyadenosine activity in patients with untreated, indolent non-Hodgkin's lymphoma

Based on the encouraging results of the use of 2-chlorodeoxyadenosine ([2-CdA], cladribine) in patients with advanced, low-grade lymphomas resistant to conventional therapy and the acceptable toxicity profile encountered, we conducted a phase II trial of 2-CdA in patients with untreated indolent lymphomas. Twenty-eight patients with untreated low- grade lymphomas were given 2-CdA at 0.1 mg/kg/d as a 7-day continuous infusion every 28 to 35 days. A total of 89 courses, median of three courses per patient, of 2-CdA were administered. Seventeen men and 11 women with a median age of 58 years were treated. Fifteen patients had diffuse small lymphocytic (8 with plasmacytoid features), 10 had follicular small cleaved-cell, and there were single patients with monocytoid B-cell, mantle cell and mucosa-associated lymphoid tissue (MALT) lymphoma histologies. All 28 patients were evaluable for toxicity and 26 were evaluable for response. Nine (35%) patients (4 with diffuse small lymphocytic, 3 with follicular small cleaved-cell, 1 with mantle cell, and 1 with MALT lymphoma) achieved a complete response, and 14 (54%) patients (8 with diffuse small lymphocytic, 5 with follicular small cleaved-cell, and 1 with monocytoid B-cell lymphoma) achieved a partial response, for an overall response rate of 88%. The median response duration was 10 months (range, 3 to 44+). Myelosuppression was the principal toxicity. Actuarial survival at 60 months from initial diagnosis was 60% (95% confidence interval, 35% to 82%) and at 48 months from treatment onset was 62% (95% confidence interval, 39% to 83%). These results establish the major activity of 2- CdA in patients with untreated indolent lymphoma, especially those with the diffuse small lymphocytic subtype.     

Helicobacter pylori-negative gastric mucosa-associated lymphoid tissue lymphomas: A review

Since Isaacson and Wright first reported on the extranodal marginal zone B-cell lymphoma of the stomach in 1983,following studies have clarified many aspects of this disease.We now know that the stomach is the most affected organ by this disease,and approximately90% of gastric mucosa-associated lymphoid tissue(MALT) lymphomas are related to Helicobacter pylori(H.pylori) infection.This implies that approximately 10% of gastric MALT lymphomas occur independent of H.pylori infection.The pathogenesis of these H.pylori-negative gastric MALT lymphomas remains unclear.To date,there have been several speculations.One possibility is that genetic alterations result in nuclear factor-kappa B(NF-κB) activation.Among these alterations,t(11;18)(q21;q21) is more frequently observed in H.pylori-negative gastric MALT lymphomas,and such translocation results in the synthesis of fusion protein API2-MALT1,which causes canonical and noncanonical NF-κB activation.Another possibility is infection with bacteria other than H.pylori.This could explain why H.pylori eradication therapy can cure some proportions of H.pylori-negative gastric MALT lymphoma patients,although the bacteria responsible for MALT lymphomagenesis are yet to be defined.Recent advances in endoscopy suggest magnifying endoscopy with narrow band imaging as a useful tool for both detecting gastric MALT lymphoma lesions and judging the response to treatment.A certain proportion of H.pylori-negative gastric MALT lymphoma patients respond to eradication therapy; hence,H.pylori eradication therapy could be considered as a first-line treatment for gastric MALT lymphomas regardless of their H.pylori infection status.     

HLA-DQA1*0103-DQB1*0601 haplotype and Helicobacter pylori-positive gastric mucosa-associated lymphoid tissue lymphoma.

BACKGROUND & AIMS: Immune responses to Helicobacter pylori are important in the pathogenesis of gastric mucosa-associated lymphoid tissue (MALT) lymphoma. In this retrospective case study, we investigated whether certain alleles and haplotypes of major histocompatibility complex genes are associated with gastric MALT lymphoma and the efficacy of H pylori eradication therapy on the lymphoma. METHODS: Blood samples were obtained from 18 patients with H pylori-positive gastric MALT lymphoma (5 men and 13 women; age range, 51-80 years), 30 patients with H pylori-positive non-ulcer dyspepsia (17 men and 13 women; age range, 37-77 years), and 30 patients with H pylori-negative non-ulcer dyspepsia (12 men and 18 women; age range, 37-77 years). HLA-DQA1 and DQB1 allele typing was performed by use of a polymerase chain reaction sequence-specific oligonucleotide procedure. All patients with MALT lymphoma were treated with H pylori eradication therapy and followed up by repeated endoscopy and biopsy. RESULTS: We found a significant increase in alleles HLA-DQA1*0103 and HLA-DQB1*0601, and a haplotype DQA1*0103-DQB1*0601, in MALT lymphoma patients when compared with non-ulcer dyspepsia patients who were either H pylori-positive or not and with a healthy control population. After H pylori eradication, the lymphomas regressed completely in all 10 patients who possessed the DQA1*0103-DQB1*0601 haplotype but in only 4 of the 8 without this haplotype (P = .023). CONCLUSIONS: DQA1*0103-DQB1*0601 haplotype-positive gastric MALT lymphoma is likely to respond to therapy by eradication of H pylori.     

Regression of primary high-grade gastric B-cell lymphoma following Helicobacter pylori eradication.

The causative association between Helicobacter pylori and gastric mucosal inflammation is well established. The inflammatory process leads to the acquisition of mucosa-associated lymphoid tissue (MALT) by the stomach. Evidence links H. pylori gastritis with the development of low-grade primary gastric lymphoma with a phenotype specific for lymphoma of MALT type. It is now accepted that primary low-grade MALT lymphomas regress with H. pylori eradication therapy. However, the response of primary, diffuse, large-cell gastric lymphoma to H. pylori eradication therapy is still not established. We report a case of a primary high-grade gastric lymphoma regressing after H. pylori eradication therapy.     

Rapid development of diffuse large B-Cell lymphoma after successful eradication of Helicobacter pylori for gastric MALT lymphoma

Primary low-grade mucosa-associated lymphoid tissue (MALT) lymphoma of the stomach has a potential to transform to high-grade diffuse large B-cell lymphoma (DLBCL). However, the clonal relation between MALT lymphoma and de novo DLBCL is still controversial. We report here three patients with Helicobacter pylori (H. pylori)-positive gastric MALT lymphoma rapidly progressing to DLBCL at the same site after successful eradication of H. pylori. Although MALT lymphomas in our cases did not possess t(11; 18)(q21;q21), sequence analysis of the rearranged immunoglobulin heavy chain gene showed no clonal relation between preceding MALT lymphoma cells and de novo DLBCL cells at the same site. These findings question the scenario of direct clonal progression of low-grade MALT lymphomas without t(11; 18)(q21;q21) to DLBCL and serve as a reminder of the risk of the progression of DLBCL with a distinct clonality immediately after H. pylori eradication for low-grade MALT lymphoma.