Low grade gastric B-cell MALT lymphoma progressing into high grade lymphoma. Clonal identity of the two stages of the tumour, unusual bone involvement and leukemic dissemination

The Spectrum of Helicobacter-Mediated Diseases

Helicobacter pylori is the leading cause of peptic ulcer disease. The infection has been implicated in more than 75% of duodenal ulcer cases and 17% of gastric ulcer cases. H. pylori has been classified as a human carcinogen, since it is the main cause of distal gastric adenocarcinoma and B cell mucosa-associated lymphoid tissue lymphoma. Evidence also links H. pylori with extragastric conditions including iron deficiency anemia, idiopathic thrombocytopenic purpura, and vitamin B₁₂ deficiency. Studies indicate that H. pylori may be protective against other conditions of the gastrointestinal tract (e.g., reflux esophagitis and related pathologies) and elsewhere in the body (e.g., asthma). The infection is asymptomatic in the vast majority of cases; more serious outcomes occur in only 10-15% of infected individuals. Despite extensive research over the past 3 decades, there is no effective vaccine, and the circumstances leading to disease development remain unclear. In addition, there is now a growing prevalence of antimicrobial resistance in H. pylori. This review discusses these important issues.

Trends in the management of gastric cancer over a 32-year period: a French population-based study

BACKGROUND

Gastric cancer is still generating interest because of its poor prognosis. The aim of this study was to investigate time trends in diagnostic assessment, patterns of care, and survival of gastric cancers.

METHODS

We considered 5,010 gastric cancers diagnosed between 1976 and 2007 in a well-defined French population. Logistic regressions were used to identify factors associated with R0 resection and operative mortality. A multivariate relative survival analysis was performed.

RESULTS

Diagnostic modalities have changed. Since 1988, endoscopy is performed when gastric cancer is suspected (95.5%). However, there has been no strong variation in stage over time: the proportion of stage I cancers increased from 5.5% to 13.4% between the periods 1976-1979 and 2004-2007 (p < 0.001) whereas that of advanced cases remained stable, 64.8% and 65.0%, respectively. R0 resections rose from 36.7% (1976-1979) to 46.7% between 1980 and 1999, and decreased to 32.7% thereafter. Age, tumor location, and period were associated with R0 resection. Neoadjuvant and adjuvant chemotherapy were rarely used before 2000, then reached 15.0% and 19.1%, respectively, during the later period. Operative mortality after R0 resection decreased from 18.3% during the 1976-1979 period to 4.3% during the 2004-2007 period (p < 0.001). Prognosis slightly improved during the three first periods, from 13.0% to 22.6%, then leveled off, not exceeding 26.0% thereafter. Stage, age, histology, and time period significantly influenced survival.

CONCLUSION

Changes in diagnostic modalities were associated with minor changes in stage and prognosis for gastric cancer. Earlier diagnosis and new therapeutic strategies are the best way to improve the prognosis.

Cavitary pulmonary involvement of diffuse large B-cell lymphoma transformed from extra nodal marginal zone B-cell lymphoma MALT type

We describe a case of pulmonary diffuse large B-cell lymphoma (DLBCL), which was thought to arise from extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma). A 68-year-old woman presented with a 2-month history of cough and bloody sputum. The chest X-ray and computed tomography revealed a mass with cavitation in the right lower lobe. Transbronchial biopsy specimens revealed a granulomatous infiltration without malignant cells. However, diagnosis of MALT lymphoma was established from gastric biopsy specimen. Subsequently, a right lower lobectomy was performed because of hemoptysis. Examination of the resected specimen revealed a diffuse large B-cell lymphoma, which was considered to have transformed from MALT lymphoma, because both lung and stomach lesions had the chromosomal translocation t(11;18)(q21;q21) in common. In addition, there were no nodules, masses, alveolar or interstitial infiltrates in the lung fields, which are usually observed in the case of marginal zone B-cell lymphoma of bronchial mucosa-associated lymphoid tissue. These findings indicate that involvement of DLBCL have to be considered in patients with MALT lymphoma and cavitary lesion of the lung.

Predictive value of endoscopy and endoscopic ultrasonography for regression of gastric diffuse large B-cell lymphomas after Helicobacter pylori eradication

BACKGROUND

Some gastric diffuse large B-cell lymphomas have been reported to regress completely after the successful eradication of Helicobacter pylori. The aim of this study was to investigate the clinical characteristics of gastric diffuse large B-cell lymphomas without any detectable mucosa-associated lymphoid tissue (MALT) lymphoma that went into complete remission after successful H. pylori eradication.

PATIENTS AND METHODS

We examined the effect of H. pylori eradication in 15 H. pylori-positive gastric diffuse large B-cell lymphoma patients without any evidence of an associated MALT lymphoma (clinical stage I by the Lugano classification) by endoscopic examination including biopsies, endoscopic ultrasonography, computed tomography, and bone marrow aspiration.

RESULTS

H. pylori eradication was successful in all the patients and complete remission was achieved in four patients whose clinical stage was I. By endoscopic examination, these gastric lesions appeared to be superficial. The depth by endoscopic ultrasonography was restricted to the mucosa in two patients and to the shallow portion of the submucosa in the other two patients. All four patients remained in complete remission for 7-100 months.

CONCLUSION

In gastric diffuse large B-cell lymphomas without a concomitant MALT lymphoma but associated with H. pylori infection, only superficial cases and lesions limited to the shallow portion of the submucosa regressed completely after successful H. pylori eradication. The endoscopic appearance and the rating of the depth of invasion by endosonography are both valuable for predicting the efficacy of H. pylori eradication in treating gastric diffuse large B-cell lymphomas.

Frequent and rapid progression of atrophy and intestinal metaplasia in gastric mucosa of patients with MALT lymphoma

OBJECTIVES

Association of gastric mucosa-associated lymphoid tissue (MALT) low-grade lymphoma and adenocarcinoma has repeatedly been reported. The aim of this study was to evaluate the frequency and the spreading of atrophy and intestinal metaplasia in gastric mucosa of patients with gastric MALT lymphoma followed after conservative treatment.

METHODS

Forty-five patients (mean age 45 +/- 2.1 yr) with gastric MALT lymphoma, treated by Helicobacter pylori eradication, chemotherapy with per os single alkylating agents, or both treatments have been followed by gastroscopy with biopsies in antrum and corpus at least once a year. Univariate and multivariate analysis evaluated the association between the appearance of atrophy and intestinal metaplasia in antrum or corpus and different factors related to patients, H. pylori status, lymphoma features, and treatment. In addition, histological aspects of gastric biopsies at the diagnosis period and at the end of follow-up were compared with those of two control groups of age-matched patients with H. pylori gastritis.

RESULTS

At the diagnosis time, only intestinal metaplasia in corpus was more frequent in patients with gastric MALT lymphoma than in patients with nonulcer dyspepsia. Within median follow-up of 54.4 months (range 9-196), the percentage of patients with gastric atrophy and intestinal metaplasia increased significantly and became significantly higher than in age-matched nonulcer dyspepsia patients. Multivariate analysis showed significant association between corpus intestinal metaplasia and corpus atrophy, intestinal metaplasia in antrum, and duration of the follow-up.

CONCLUSIONS

Conservative management of gastric MALT lymphoma including H. pylori eradication is associated with progression of gastric atrophy and intestinal metaplasia with frequent involvement of the corpus which is known to be a precancerous condition. These findings show that long-term endoscopic monitoring should be recommended in such patients.

Gastric B-cell mucosa-associated lymphoid tissue (MALT) lymphoma in an animal model of 'Helicobacter heilmannii' infection

While Helicobacter pylori is accepted as the dominant human gastric bacterial pathogen, a small percentage of human infections have been associated with another organism, commonly referred to as 'Helicobacter heilmannii', which is more prevalent in a range of animal species. This latter bacterium has been seen in association with the full spectrum of human gastric diseases including gastritis, peptic ulceration, and gastric carcinomas, including gastric B-cell mucosa-associated lymphoid tissue (MALT) lymphoma. This study describes an analysis of the pathogenic potential of a number of 'H heilmannii' isolates in an animal model of gastric MALT lymphoma. BALB/c mice were infected with ten different 'H heilmannii' isolates originating from both human and animal hosts. The animals were examined at various time points for up to 28 months after infection. The infected animals initially developed a chronic inflammatory response within 6 months. This histological response increased in severity with the length of infection, with the development of overt lymphoma in some animals 18 months after infection. MALT lymphomas were detected in up to 25% of the infected animals. The prevalence of lymphoma was dependent on the length of infection and the origin of the infecting isolates. A range of other histological features accompanied the lymphocytic infiltration, including invaginations of the gastric epithelium and associated hyperplastic tissue, mucus metaplasia, and a small number of diffuse large B-cell lymphomas. The ability to manipulate experientially the presence of the bacterium in the animal model will allow further studies examining the role of antigen drive in the development of Helicobacter-associated MALT lymphoma.

No evidence of a correlation between BCL10 expression and API2-MALT1 gene rearrangement in ocular adnexal MALT lymphoma

In the present study, 62 cases of ocular adnexal lymphoproliferative disorders were reviewed clinicopathologically. Of them, 51 were extranodal marginal zone B-cell lymphoma (MALT lymphoma), five were diffuse large B-cell lymphoma (DLBCL), one was peripheral T-cell lymphoma, one was NK/T cell lymphoma, nasal type, and four were reactive lymphoid hyperplasia. These lymphoma cases showed a favorable clinical course and localized disease, except for the case of NK/T cell lymphoma, although 19 cases (32.8%) had a recurrence of disease. To clarify the correlation between BCL10 protein expression and API2-MALT1 gene rearrangement, the 51 cases of MALT lymphoma and 5 cases of DLBCL were analyzed by immunohistochemical and RT-PCR methods. Nuclear BCL10 expression was identified in 58% of MALT lymphoma cases, but not in any DLBCL cases. There was no evidence of a correlation between aberrant nuclear BCL10 expression and the clinical parameters examined in the present study. API2-MALT1 transcription was not demonstrated in either the MALT lymphoma cases or the DLBCL cases studied using a multiplex one-tube reverse transcriptase-PCR method. These findings indicate that the nuclear expression of BCL10 is unlikely to correlate with the API2-MALT1 fusion gene in ocular adnexal MALT lymphoma.

Chromosomal translocations involved in non-Hodgkin lymphomas

CONTEXT

The discovery that recurrent chromosomal translocations are involved in the pathogenesis of non-Hodgkin lymphomas has greatly improved our understanding of these diseases and revolutionized their diagnosis.

OBJECTIVE

To review the mechanisms by which chromosomal translocations occur and contribute to the pathogenesis of various types of non-Hodgkin lymphomas and to review the utility of molecular genetic methods for the assessment of these translocations.

DATA SOURCES AND STUDY SELECTION

Primary research studies and reviews published in the English language that focus on chromosomal translocation and non-Hodgkin lymphomas.

DATA EXTRACTION AND SYNTHESIS

Chromosomal translocations, which usually result in oncogene activation, occur in many types of B- and T-cell lymphoma, and their detection is helpful for establishing an accurate diagnosis and monitoring disease following therapy. However, the precise mechanisms that explain how translocations occur remain unknown, although for some types of translocations a clear relationship has been established with immunoglobulin gene rearrangement mechanisms. In recent years, a number of genes deregulated by chromosomal translocations have been identified, and the detailed molecular mechanisms by which chromosomal translocations contribute to the pathogenesis of non-Hodgkin lymphoma are beginning to be elucidated.

CONCLUSIONS

Molecular genetic analysis has played a major role in improving our understanding of B- and T-cell non-Hodgkin lymphomas and has allowed more precise definition of lymphoma types. Molecular genetic tests to detect these translocations are important ancillary tools for the diagnosis and classification of malignant lymphomas.

Helicobacter pylori and carcinogenesis of gastric B-cell lymphomas

Primary non-Hodgkin's lymphomas of the stomach are associated with Helicobacter pylori infection. We analyzed gastric lymphoma onset data with respect to prior H. pylori infections based on the multistage theory of carcinogenesis. This theory provides a link between epidemiological data and biological processes. The study involved 133 patients, aged 29-75 years, diagnosed with marginal zone B-cell lymphoma (MZBL) and diffuse large cell B-cell lymphoma (DLBL). A 2-parametric Weibull model was applied to MZBL and DLBL onset data. Median age of diagnosis of MZBL (DLBL) was 59 years (55 years) in males and 65.5 years (64 years) in females. Infection with H. pylori was found in 81.3% (59.5%) of the patients diagnosed with MZBL (DLBL). Lymphoma latency data were fitted to Weibull distributions with a shape parameter of 5.7 for MZBL cases and 4.2 for DLBL. The shape parameter that indicates the number of steps in carcinogenesis was approximately independent of the status of infection with H. pylori in DLBL in contrast to MZBL. It was shown that gastric lymphoma onset data can be described by Weibull distribution functions. The findings support the hypothesis that MZBL and DLBL have different lines of development. There is indication of stronger antigen dependency in the carcinogenesis of MZBL in comparison to DLBL.

Clinicopathological features of gastric B-cell lymphoma: a series of 317 cases

The stomach is a common site of extranodal malignant lymphoma. Here we examined the clinicopathological features of 317 gastric B-cell lymphomas and characterized the differences among low-grade mucosa-associated lymphoid tissue (MALT) lymphomas (LG), high-grade MALT lymphomas (HG), follicular lymphomas (FL) and diffuse large B-cell lymphomas (DL). Cases included 126 DL, 71 HG, 98 LG, 10 FL, three Burkitt's lymphoma and nine of undefined type. The age range of patients was as follows: LG, 14-96 years (mean, 61.1); HG, 20-87 years (mean, 63.9); DL, 16-88 years (mean, 62.8); and FL, 54-76 years (mean, 65.5). There were no differences in age with respect to tumor type. There were more women patients with LG (female:male, 55:43), while males predominated among DL patients (54:72). The sexes were represented almost equally in HG cases (34:37). Histological findings, especially in DL tumors, correlated significantly to the gross appearance of mass formation. Dutcher bodies were encountered mainly in HG or LG cases. Our results showed no differences in age, sex or site of disease between LG, HG and DL tumors. However, the grade of malignancy correlated strongly to gross appearance. Dutcher bodies were important for the diagnosis of gastric MALT lymphoma.

Monoclonal gammopathy after low-grade MALT lymphoma: evidence for a second neoplasm

We report the case of a patient with lymphoma of the salivary gland, at first diagnosed as lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) but later found to infiltrate the bone marrow. At diagnosis, the patient had a polyclonal increase of gamma-globulins. Five years after initial diagnosis, the patient presented with monoclonal gammopathy and infiltration of the bone marrow with neoplastic cells. Initially, the patient had received chemotherapy with different protocols (including etoposide, cyclophosphamide, fludarabin, methotrexate, and vincristine), none of which induced a lasting response. Therapy with rituximab (chimeric anti-CD20 monoclonal antibody) finally led to partial remission. Eighteen months after rituximab, progressive lymphoma in the abdomen and a monoclonal gammopathy developed. The bone marrow showed infiltration by lymphoplasmacytoid cells (monoclonal expression of the light-chain type lambda, positive for CD20, heterogeneous expression of CD45). The patient achieved another short clinical response with 4 cycles of the CHOP-protocol, but soon the lymphoma progressed again. Five years and 8 months after the initial diagnosis, the patient died from septicemia and progressive lymphoma. By polymerase chain reaction (PCR) for the IgH gene it was shown that lymphoma cells were initially oligoclonal in the salivary gland and, later, biclonal in the bone marrow. Sequencing of two bands of apparently same length showed that these manifestations of lymphoma were not identical. Taken together, our data show that the initial low-grade oligoclonal MALT lymphoma was no longer present and a more aggressive biclonal lymphoma with plasmacytoid differentiation had developed. The new lymphoma was clonally distinct and produced high amounts of monoclonal IgG lambda by immunoelectrophoresis. The relationship of the second lymphoma to the initial MALT lymphoma is discussed.

Marginal zone cell lymphoma--an update on recent advances

The marginal zone represents one of the distinct compartments of the B-cell area in lymphoid tissues. It is especially well developed in the spleen and in Peyer's patches of the gut, but not in lymph nodes, with the exception of the ones in the mesenterium. However, the pronounced proliferation of so-called 'monocytoid B-cells' that may be seen in some inflammatory conditions of the lymph node may be regarded as a nodal reactive marginal zone cell expansion. The cellular compositions of the marginal zone and the monocytoid B-cell proliferation are similar and both show a heterogeneous population of B-cells, of which the functions are being slowly unravelled. Neoplasms originating in the marginal zone have been recognized in the past and are listed in the REAL classification as marginal zone B-cell lymphomas including extranodal MALT-type lymphomas, splenic marginal zone lymphomas and nodal (monocytoid) marginal zone lymphomas. Marginal zone cell lymphomas display a broad morphological spectrum, which is reflected by the heterogeneity of the cellular composition and the variation in the growth pattern of the lymphoma, but is independent of the anatomical site. All three marginal zone cell lymphomas share immunophenotypic, genetic and chromosomal similarities which will be discussed. The morphologic features are dealt with only briefly as they have been extensively discussed elsewhere.

Primary gastrointestinal B-cell lymphoma. A clincopathological and immunohistochemical study of 61 cases with an evaluation of prognostic parameters

We hereby present a retrospective clinicopathological and immunohistochemical study of surgically resected primary gastrointestinal (GI) lymphoma with an analysis of parameters of potential prognostic relevance. From a larger series of 144 cases of primary GI lymphomas, we chose 61 cases with sufficient clinical follow-up (mean 60, range 1-219 months), classified either as extranodal marginal zone B-cell lymphoma of MALT type (MALT lymphoma) or diffuse large B-cell lymphoma (DLBCL), after having excluded other subtypes. In addition to conventional clinical and morphological parameters, the expression levels of Ki-67 (MIB-1), bcl-2 and p53 were evaluated for prognostic significance. Twenty-one (34.4%) cases were classified as pure low grade marginal zone B-cell lymphoma of MALT type, 12 (19.7%) cases as low grade MALT lymphoma with a high grade component (mixed type), and 28 (45.9%) cases as primary extranodal DLBCL. Most of the lymphomas (53/61; 86.9%) were localized in the stomach, 3 (4.9%) in the small bowel, 3 (4.9%) multifocal in both stomach and small intestine and 2 (3.3%) in the large bowel. MIB-1 expression in more than 30% of tumor cells was detected in 42 (68.6%), bcl-2 expression in 20 (32.8%) and p53 accumulation in more than 10% of neoplastic cells in 16 (26.2%) lymphomas. Both high Ki-67 expression and p53 accumulation were more prevalent in the DLBCL. 30 (49%) patients showed lymph node involvement at surgery, 14 (23%) patients suffered tumor recurrence, and 24 (38.5%) died during the follow-up period. Tumor recurrence occurred primarily in patients who had presented lymph node involvement (9/14, 64.3%). The 5-year survival rate was 66.1% for all patients. Important prognostic factors for overall survival were tumor stage (p < .004) and p53 accumulation (p < .05) in univariate analysis, and tumor stage in multivariate analysis (p < .001). Although p53 accumulation did not reach statistical significance in our small study group, it may be both important in the transformation of low grade MALT lymphoma and an indicator for aggressive behavior in high grade tumors.

Gastric marginal zone B-cell lymphomas of MALT type develop along 2 distinct pathogenetic pathways

Low-grade marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) type can transform into high-grade diffuse large B-cell lymphoma (DLBCL). Up to 60% of the MALT lymphomas contain the recently described t(11;18). However, this translocation has not been detected in any DLBCL so far. To elucidate the pathogenesis of these tumors, microsatellite screening of 24 gastric MALT lymphomas was performed and the results were compared with aberrations detected in a previous study on gastric DLBCL. The most frequent aberration, found in 21% of the MALT lymphomas that were exclusively t(11;18)-negative cases, was amplification of the 3q26.2-27 region (harboring the locus of the BCL6 gene). Allelic imbalances in regions 3q26.2-27, 6q23.3-25, 7q31, 11q23-24, and 18q21 were shared by both MALT lymphoma and DLBCL. Loss of heterozygosity in regions 5q21 (APC gene locus), 9p21 (INK4A/ARF), 13q14 (RB), and 17p13 (p53) and allelic imbalances in 2p16, 6p23, and 12p12-13 occurred exclusively in DLBCL. Only one of 10 t(11;18)-positive MALT lymphomas showed an additional clonal abnormality. These tumors thus display features of a clonal proliferation characterized by the presence of the t(11;18). However, they only rarely display secondary aberrations and do not seem to transform into DLBCL. In contrast, t(11;18)-negative MALT lymphomas show numerous allelic imbalances--some of them identical with aberrations seen in DLBCL--suggesting that this group is the source of tumors eventually transforming into high-grade DLBCL.

Prospective study of Helicobacter pylori eradication therapy in stage I(E) high-grade mucosa-associated lymphoid tissue lymphoma of the stomach

PURPOSE

High-grade mucosa-associated lymphoid tissue (MALT) lymphomas of the stomach are generally believed to be Helicobacter pylori-independent, autonomously growing tumors. However, anecdotal cases of regression of high-grade lymphomas after the cure of H pylori infection had been described. The present prospective study was conducted to evaluate the effect of anti-H pylori therapy in stage I(E) high-grade gastric MALT lymphomas.

PATIENTS AND METHODS

Sixteen patients with H pylori infection and stage I(E) gastric high-grade MALT lymphoma consented to a brief antibiotic therapy as first-line treatment from June 1995 through April 2000. Then, patients underwent intensive endoscopic follow-up examinations (+/- endoscopic ultrasonography) with biopsy to evaluate tumor response. Patients with significant improvement of gross lesions that accompanied regression of large cells were followed up without additional treatment. Patients without significant improvement were immediately referred to systemic chemotherapy.

RESULTS

Eradication of H pylori was achieved in 15 patients and was accompanied by rapid gross tumor regression and disappearance of large cells in 10. All 10 of these patients with early response had subsequent complete histologic remission of lymphoma. The complete remission rate was 62.5% (95% confidence interval, 35.8% to 89.1%). The response rate was not affected by the tumor grading (proportion of large blast cells within the tumor) but was adversely affected by the depth of tumor invasion. At a median follow-up of 43.5 months (range, 21.1 to 67.4 months), all 10 of these patients remained lymphoma-free. The median duration of complete response was 31.2 months (range, 14.4 to 49.1 months).

CONCLUSION

These results suggest that high-grade transformation is not necessarily associated with the loss of H pylori dependence in early-stage MALT lymphomas of the stomach.

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.

Primary high-grade mucosa-associated lymphoid tissue-type lymphoma of the cervix presenting as a common endocervical polyp

Lymphomas of the uterine cervix are uncommon neoplasms and typically appear as diffuse cervical enlargement. We describe a rare case of primary high-grade lymphoma of mucosa-associated lymphoid tissue of the uterine cervix in a 46-year-old white woman. The tumor, incidentally disclosed at gynecological examination, appeared as a single common polyp. Immunohistochemical investigation found the lesion to consist of a monomorphic CD20-positive infiltrate of large blasts and rare intermingling centrocyte-like lymphoid cells. A dense area of monotypic (lambda light-chain restriction) plasma cells was found beneath the endocervical mucosa; only a few scattered lymphoepithelial lesions were present. The neoplastic cells did not stain for CD5, CD10, CD23, CD43, or cyclin D1. A bone marrow biopsy displayed a paratrabecular, centrocyte-like B-cell infiltration, but no lymphadenopathy was detected by instrumental examination (computed tomographic scan, magnetic resonance imaging). The tumor was successfully treated by multiagent chemotherapy followed by total hysterectomy. To our knowledge, this case represents the second reported example of mucosa-associated lymphoid tissue-type lymphoma occurring in the uterine cervix. We highlight the very unusual gross appearance of this case and emphasize the difficulty of interpreting lymphoid infiltrates in the lower genital tract by microscopy.

Pathology of lymphoma progression

Reflecting the stepwise process of oncogenesis, lymphomas may cumulatively develop a more aggressive phenotype during the course of disease, a process referred to as lymphoma progression. Although morphological, clinical and biological aspects of lymphoma progression do not always overlap, changes in lymphoma morphology frequently indicate alterations in the clinical and biological behaviour of the disease. Indolent and aggressive lymphomas in disease progression can either be clonally related or represent clonally unrelated neoplasms. We propose to use the term 'lymphoma progression' in a biological sense denoting only clonal development of and within a lymphoma entity. The term 'composite lymphoma' should be used as a merely descriptive morphological designation for different lymphoma entities in one individual irrespective of clonal relationship. Many types of aggressive B-cell non-Hodgkin's lymphomas and Hodgkin's lymphomas are reported to secondarily develop in lymphoma progression. Genetic changes associated with lymphoma progression frequently abrogate the differentiating effects of alterations occurring in indolent lymphomas, leading to increased cell proliferation. Within different lymphoma entities, high-risk disease variants mimicking lymphoma progression exist.

Gastrointestinal lymphoma: prevention and treatment of early lesions

Gastrointestinal lymphomas comprise a group of distinct clinicopathological entities. Differences in lifestyle and environmental factors between countries could account for the variety in the distribution of the main subtypes: low-grade B-cell lymphomas of the mucosa-associated lymphoid tissue type, alpha-chain disease and enteropathy (coeliac disease)-associated T-cell lymphoma (EATL). The possibility of preventing these lymphomas implies a knowledge of their natural history together with an identification of potential predisposing factors. The development of the lymphoid hyperplasia and subsequently low-grade lymphoma with the possibility of high-grade transformation is a multifactorial process involving both antigenic and host-related factors. The pathogenic role of Helicobacter pylori and gluten has been demonstrated in gastric lymphoma and enteropathy-associated T-cell lymphoma respectively, while environmental factors, especially non-specific bacterial ones, may play a major role in the pathogenesis of alpha-chain disease. The most difficult task in preventing these lymphomas is the recognition of early lesions likely to regress after the removal of the exogenous stimulus.

Prognostic significance of the histopathologic recognition of low- and high-grade components in stage I-II B-cell gastric lymphomas

The prognostic value of histopathologic features was assessed in 83 patients with stage I-II gastric B-cell lymphomas (PGL). The following histotypes were considered: low-grade mucosa-associated lymphoid tissue (MALT)-type lymphoma (LGML; n = 35), diffuse large B-cell lymphoma with areas of MALT-type lymphoma (DLCLML; n = 20) and diffuse large B-cell lymphoma without areas of MALT-type lymphoma (DLCL; n = 28). Low-grade (LG) and high-grade (HG) components, lymphoepithelial lesions (LEL), size of cells giving rise to LEL, and amount and growth pattern of large cells (LC) were analyzed. Five-year cause-specific survival (CSS) for patients with LGML, DLCLML, and DLCL were 94%, 84%, and 64%, respectively (p = 0.05). LG component or LEL were associated with a significantly longer 5-year CSS, whereas the presence of an HG component, defined as clustered LC greater than 10% of neoplastic population, was significantly related to a shorter survival. Lymphomas with LC disposed in clusters were associated with a worse survival in comparison with cases with scattered LC. The presence of scattered LC 5%-10% appeared irrelevant in LGML. When analysis was limited to DLCLML/ DLCL patients, the presence of LG component or LEL was associated with a significantly longer 5-year CSS, whereas the existence of LEL formed by LC (HG LEL) did not modify survival. Multivariate analysis, adjusted by the main prognostic factors, confirmed the independent and significant association between histopathologic categorization and survival. Age, stage, lactate dehydrogenase (LDH) ratio, thrombocytopenia, and use of chemotherapy had independent prognostic value. In conclusion, histopathologic categorization is an independent prognosticator in PGL. The formation of compact clusters by LC, rather than their amount, is a true prognostic variable. The presence of scattered LC 5%-10% appears irrelevant in LGML. LG component and LEL are favorable predictors in HG lymphomas, helping to identify two subsets of DLCL with different prognosis.

A critical review of the effect of Helicobacter pylori eradication on gastric MALT lymphoma

Low-grade B-cell lymphomas of mucosa-associated lymphoid tissue (MALT) are thought to arise within organized lymphoid tissue in the gastric mucosa that is most frequently acquired in response to Helicobacter pylori infection. This close association between the organism and the lymphoma is further reflected by the demonstration that the proliferation of the lymphoma cells can be driven by the presence of H. pylori organisms through a complex path of cellular interactions involving specific T cells. From these observations it was suggested that removal of one of the proliferative drives to the neoplastic cells in the form of eradication of the organism might induce a remission in the tumor. Several large multicenter studies are now underway to consider this question, and interim reports suggest that long-term remissions can be induced in low-grade MALT lymphomas in 70% to 80% of cases. The lymphomas that are most likely to respond to H. pylori eradication are those that are located superficially within the gastric mucosa. It has been suggested that certain genetic abnormalities, such as t(11;18) and the Bcl-10 mutation, may be associated with lack of response to this therapy. Recurrences of low-grade lymphoma are encountered in patients treated by H. pylori eradication, but these appear to be infrequent and may be self-limiting and spontaneously regress without further therapy.

Heterogeneity of the API2-MALT1 gene rearrangement in MALT-type lymphoma

The translocation t(11;18)(q21;q21), which is the most frequent chromosomal aberration in extranodal marginal zone B cell lymphomas of MALT-type, was characterised in a series of 34 biopsies, including 18 gastric non-Hodgkin's lymphomas (NHL) of MALT-type, six MALT-type NHL of extragastral origin and 10 extranodal large B cell lymphomas (LBL). Based on fluorescence in situ hybridisation, STS-PCR analysis and screening of genomic PAC libraries, a physical map of contiguous DNA probes on chromosome 11 was constructed containing the anti-apoptotic genes API2 and API1 adjacent to the translocation breakpoint. RACE-PCR experiments revealed MALT1 the chromosome 18-derived fusion partner of API2, which has also been reported recently by other groups. RT-PCR analysis and DNA sequencing demonstrated the expression of an API2-MALT1 fusion transcript in 18/24 gastral and extragastral MALT-type lymphomas. In none of 10 LBLs was a translocation specific RT-PCR product detected. Five variants of the fusion transcript were identified and in all instances the open reading frame of the fused portion of the MALT1 gene was maintained. The molecular analysis of these variants allowed the design of optimised assays for the diagnosis of the API2-MALT1 gene rearrangement.

The product of the t(11;18), an API2-MLT fusion, marks nearly half of gastric MALT type lymphomas without large cell proliferation

Recently we demonstrated that the t(11;18)(q21;q21) associated with extranodal marginal zone B cell lymphomas of MALT type results in the expression of a chimeric transcript fusing 5' API2 on chromosome 11 to 3' MLT on chromosome 18. Here we report the development of an RT-PCR approach for the detection of the API2-MLT fusion transcript and its application for the analysis of 58 cases of gastric lymphoma. Initially nested PCR amplification was combined with Southern analysis using internal API2 and MLT probes. A genuine API2-MLT fusion transcript of variable length was demonstrated in 11 out of 58 cases. Sequence analysis revealed that in all cases the breakpoint on chromosome 11 occurred between exons 7 and 8 of the API2 gene. In contrast, the breakpoints on chromosome 18 appeared to be heterogeneous as fusions to bp 814, 1123, and 1150, respectively, of MLT were observed. These observations allowed us to work out a highly sensitive diagnostic test for the API2-MLT fusion on an ABI Prism 7700 sequence detector that confirmed the results of our initial approach. The API2-MLT fusion was found in 48% of gastric marginal zone cell lymphomas of MALT type that did not contain a large cell component and it was lacking in all other lymphomas of the stomach.

Clinicopathological features of gastric mucosa associated lymphoid tissue (MALT) lymphomas: high grade transformation and comparison with diffuse large B cell lymphomas without MALT lymphoma features

AIMS

To investigate the clinicopathological differences among gastric low grade MALT lymphomas (low MALT), large B cell lymphomas with low grade components (secondary high grade MALT lymphomas, high MALT), and diffuse large B cell lymphomas without low grade features (primary high grade MALT lymphomas, DLL).

METHODS

Clinicopathological and morphological characters of 126 gastric lymphoma cases were studied: 82 cases of low MALT lymphoma including 40 that were surgically resected, 17 cases of high MALT lymphoma including 13 surgically resected, and 27 cases of DLL including 12 surgically resected.

RESULTS

Age ranges were as follows: low MALT lymphoma, 34 to 85 years (mean 59.9); high MALT lymphoma, 53 to 88 years (mean 68.5); DLL, 29 to 83 years (mean 62.3). The average age for low and high MALT lymphomas was significantly different (p < 0.05), but there were no differences in other comparisons. There was a female predominance of low MALT lymphoma patients (female to male ratio, 47/35), while for high MALT patients the ratio was almost even (8/9), and for DLL patients there was a male predominance (11/16). Examination of surgically resected material showed that MALT lymphomas had a wider distribution in the gastric wall than DLL.

CONCLUSIONS

The findings suggest that at least some of the high grade gastric lymphomas, especially in patients younger than the fifth decade, do not originate from high grade transformation of low MALT lymphomas. It seems to take about one decade at least for high grade transformation of low MALT lymphomas.

Exclusive detection of the t(11;18)(q21;q21) in extranodal marginal zone B cell lymphomas (MZBL) of MALT type in contrast to other MZBL and extranodal large B cell lymphomas

Extranodal mucosa-associated lymphoid tissue (MALT)-type lymphomas and nodal and splenic marginal zone B cell lymphomas (MZBL) share morphological and immunophenotypic features with marginal zone B cells of reactive lymphoid tissues. Although displaying a similar immunophenotype, recent investigations suggest fundamental genetic differences among these subgroups. To determine the prevalence of the t(11;18) in a larger series of MALT-type lymphomas and to investigate a possible occurrence in other lymphomas, we screened 106 non-Hodgkin's lymphomas (NHL) by interphase cytogenetics using yeast artificial chromosome (YAC) probes flanking the breakpoint at 11q21. A signal constellation indicating a disruption in 11q21 and thus pointing to the presence of the t(11;18) was observed in 9 of 33 (27%) low-grade lymphomas of MALT type. The complete absence of t(11;18)-positive cells in 32 primary and secondary extranodal high-grade lymphomas suggests that low-grade lymphomas of MALT type characterized by the t(11;18) are unlikely to transform into high-grade tumors. The absence of tumor cells carrying the t(11;18) in nodal MZBL challenges the assumption that most, if not all, of these tumors represent the nodal manifestation of a so far undetected low-grade lymphoma of MALT type. The t(11;18) was not detected in a single case of 29 splenic MZBL investigated. This observation strengthens the view that splenic MZBL are biologically different from extranodal MZBL of MALT type.

Interstitial deletion of 8(q13q22) in diffuse large B-cell gastric lymphoma

An interstitial deletion in the long arm of chromosome 8 as the sole structural anomaly was detected in a primary gastric diffuse large B-cell lymphoma, high-grade mucosa-associated lymphoid tissue (MALT) type, from a 74-year-old man. Low-grade MALT lymphoma was not seen in the sections submitted for examination. Helicobactor pylori organisms were found in a biopsy performed prior to resection of the tumor. The karyotype was described as 45, X,-Y,del(8)(q13q22). No rearrangement between chromosome 8 and others was detected with fluorescence in situ hybridization using a whole chromosome 8 painting probe. Fluorescence in situ hybridization with the C-MYC gene showed its normal location at 8q24 on both chromosomes 8 without rearrangement. Amplification of C-MYC was not detected in interphase cells. Deletion of 8q may represent a unique genomic alteration in this particular subtype of primary gastric lymphoma.

High-grade transformation of low-grade non-Hodgkin's lymphomas: mechanisms of tumor progression

In the natural history of low-grade non-Hodgkin's lymphomas (NHL) a prolonged indolent phase of the disease may be followed by clinical progression toward intermediate and high-grade disease. The abrupt appearance of diffuse large cell lymphoma (DLL) in patients with low-grade NHL is usually associated with an accelerated clinical course and shorter time of survival. The histologic transformation has been described for chronic lymphocytic leukemia or small lymphocytic lymphoma (CLL/SLL), follicular lymphoma (FL), mantle cell lymphoma (MCL) and lymphoma of mucosa-associated lymphoid tissue (MALT). Although the histological transformation of low-grade lymphomas are relatively frequent, the clonal relationship between the two neoplasms and pathogenetic mechanisms underlying the progression of the disease are widely debated. In this review, we will focus on the possible relationship between the low-grade and the transformed high-grade NHLs and genetic lesions that may be associated with the histologic transformation and clinical progression of the disease.

PCR-based clonality analysis: a reliable method for the diagnosis and follow-up monitoring of conservatively treated gastric B-cell MALT lymphomas?

AIMS

We evaluated polymerase chain reaction (PCR) amplification of specific immunoglobulin heavy chain (IgH) gene rearrangements as a means of demonstrating monoclonality during follow-up of conservatively treated gastric MALT lymphoma, and compared the reproducibility of PCR on sequential frozen and paraffin-embedded endoscopic biopsies. We established an association between clonality detected by PCR and the histological observations.

METHODS AND RESULTS

Sixty-nine pairs of sequential frozen and paraffin-embedded endoscopic biopsies from 21 conservatively treated patients were graded according to the Wotherspoon-Isaacson histological scoring system, which provides a measure of diagnostic confidence on a scale 0-5. PCR amplification of the IgH gene was performed using FR3/JH and FR2/JH primers. 68/69 paired samples (98.5%) showed identical mono- or polyclonal PCR amplification patterns. Forty-seven out of 48 pairs of samples sharing similar histological features produced identical amplification patterns in both fresh and paraffin-embedded tissues. In comparison with the histological grading, monoclonality was detected in 64.2% and 41.6% of samples scored 5 and 4, respectively. Conversely, among 64 samples scored 0-3, a monoclonal pattern was observed only in two samples, one of which was from a patient who relapsed 9 months later.

CONCLUSIONS

PCR-based clonality analysis by demonstration of specific IgH gene rearrangement can be easily and reliably performed on both frozen and paraffin-embedded endoscopic biopsies. In conjunction with histological observation, this method can be used as a complementary tool to monitor MALT lymphoma regression during conservative treatment.

Other cancers in patients with gastric MALT lymphoma

Patients with Hodgkin's disease and nodal non-Hodgkin's lymphomas seem to have an excess risk for other cancers. A high incidence of other cancers has also been found in some series of patients with gastric MALT lymphomas. In a series of 136 patients with gastric MALT lymphomas the occurrence and features of other cancers have been described. In order to evaluate their occurrence statistically (excluding skin cancers) standard incidence ratios (SRI) have been calculated, using the incidence rates of a Cancer Registry in Spain as a reference. A Cox's multivariate proportional hazard model was fitted in order to evaluate the influence of age, sex, histological grade and treatment with chemotherapy or chemotherapy plus radiotherapy in the development of other non-skin cancers occurring after the diagnosis of MALT lymphoma. Other cancers were detected in 16 of the 136 patients (11.7%); the other cancer was detected prior to MALT gastric lymphoma in 6 patients (4.41%), concomitantly in 4 (2.9%) and after diagnosis of the lymphoma in 6 (4.41%). Other cancers occurred in 14.4% of the male and in 8.3% of the female patients; in 12% of the patients with low grade and in 11% of the patients with high grade lymphomas. Of the 6 cancers that occurred after diagnosis of the gastric lymphoma, 3 did in the 80 patients (3.7%) that had been treated with chemotherapy, 1 in the 3 cases (33%) treated with chemotherapy and radiotherapy and 2 in the 53 patients (3.7%) who had not received chemotherapy or radiotherapy. The most frequent other cancers were lymphoid neoplasms and gastric carcinoma. There was not an excess of other cancers in the whole cohort or in the sex or histological grade strata. There was an excess close to significance (SIR =2.59; 95% CI:0.98-6.88) in the patients under 50 years of age. In the Cox's analysis, age, sex, histological grade and treatment did not influence the occurrence of other cancers after the diagnosis of lymphoma. In conclusion, in patients with gastric MALT lymphoma other cancers also occur. An excess incidence was not demonstrated, although it may exist in patients under 50 years. Of special importance is the occurrence of gastric cancer that appears concomitantly or after gastric lymphoma.

Lymphomas in patients with Sjögren's syndrome: review of the literature and physiopathologic hypothesis

The occurrence of non Hodgkin's lymphoma (NHL) is the most serious complication of Sjögren's syndrome (SS). Taking the opportunity to study 16 patients with lymphoma and an underlying SS, we performed a review of literature concerning SS and lymphoma and made an hypothesis on the physiopathology of lymphoproliferation in patients with SS. Lymphomas occurring in patients with SS are in most cases low grade marginal zone lymphomas (MZL). They arise frequently in mucosal extranodal sites, not only in the salivary glands but also the stomach and the lung. These lymphomas are not associated with viruses including hepatitis C virus (HCV), Epstein-Barr virus, human herpes virus 8 or human T lymphotropic virus-I, known to be present in other types of lymphomas. Some of the translocations or mutations of oncogenes or anti-oncogenes described in other lymphomas are also detected in SS-associated lymphomas. Lymphomas complicating SS share a number of characteristics with lymphomas complicating HCV infection. We make the assumption that, in both diseases, the first event of lymphomagenesis is the chronic stimulation, on the site of the disease, of polyclonal B-cells secreting rheumatoid factor (RF). Then, these RF B-cells may become monoclonal and disseminate in other organs. The monoclonal secreted RF complexed with polyclonal IgG may cryoprecipitate. The following step would be a chromosomal abnormality (e.g. trisomy 3) which would confer to these cells a low grade B-cell lymphoma compartment. A last event (e.g. mutation of p53) could transform this low grade B-cell lymphoma into a high grade large B-cell lymphoma. If this hypothesis was correct, most of B-cell lymphomas associated with SS should have a surface immunoglobulin with RF activity and should grow through an auto-antigen driven process.

Distinct clonal origin of low-grade MALT-type and high-grade lesions of a multifocal gastric lymphoma

AIMS

Low-grade mucosa-associated lymphoid tissue (MALT) lymphoma and high-grade B-cell non-Hodgkin's lymphoma (NHL) of the stomach may occur simultaneously. To determine the clonal relationship between these tumours, we compared the immunoglobulin heavy chain gene (IgH) rearrangements of low and high-grade components of a multifocal gastric NHL.

METHODS AND RESULTS

The complementary determining region 3 (CDR3) of the IgH gene rearrangements were polymerase chain reaction (PCR) amplified, cloned and sequenced. The analysis of the CDR3 sequences rearranged by tumour cells of low-grade MALT and the high-grade NHL revealed different nucleic acid sequences.

CONCLUSION

These findings suggest that low-grade MALT and high-grade B-cell components of multifocal gastric NHL may represent unrelated clones.

Gastric low-grade mucosa-associated lymphoid tissue lymphomas: their histogenesis and high-grade transformation

Gastric low-grade mucosa-associated lymphoid tissue (MALT) lymphoma is a unique disease. A vast majority of lymphoma cells are centrocyte-like cells or resemble monocytoid B cells, and occasionally show plasmacytic differentiation. Immunophenotypical and immunogenotypical examinations have indicated that they are in the differentiation stage of memory B cells, whose normal counterparts are marginal zone lymphocytes or monocytoid B cells in the lymphoid tissues. It arises from chronic gastritis closely associated with Helicobacter pylori (H. pylori) infection. Mucosa-associated lymphoid tissue lymphomas of other organs are also based on acquired MALT associated with chronic inflammation or autoimmune diseases. Interestingly, the majority of gastric low-grade MALT lymphomas regress by the eradication of H. pylori. The lymphoma cells, however, are not derived from B cells reacting with H. pylori itself but from autoreactive B cells. Although the mechanism of their oncogenesis has not been clarified, previous data suggest that autoreactive B cells proliferate in response to H. pylori-specific T cells, presumably with some cytokines. The genetic instability of such B cells then induces chromosomal abnormalities including trisomy 3 and/or other genetic changes. These B cells have the ability of autonomic proliferation and, even so, they might be sensitive to T cell stimuli. Low-grade gastric lymphomas occasionally progress to high-grade malignancy. The high-grade component of MALT lymphomas are composed of large-sized lymphoma cells that are morphologically indistinguishable from nodal large B cell lymphomas. This high-grade transformation is associated with p53 abnormalities or Bcl-6 overexpression. Gastric MALT lymphoma may provide a useful model in understanding multistep lymphomagenesis.

Classification of primary gastric lymphomas according to histologic features

Histologic features of low-grade gastric lymphomas of mucosa-associated lymphoid tissue (MALT) have been extensively described, and transformation to a large cell (high-grade) lymphoma can occur. We characterize high-grade gastric lymphoma histologically in an attempt to distinguish between MALT-type and non-MALT-type lesions. We studied a series of 60 gastric lymphomas and characterized them clinically, histopathologically, and immunophenotypically. Low-grade gastric lymphomas were classified according to established criteria. High-grade lymphomas were classified in three groups based on the presence or absence of a low-grade component and lymphoepithelial lesions (LELs): 1) high-grade MALT lymphomas appearing in low-grade MALT lymphomas (LG/HG MALT lymphoma); 2) large cell lymphoma with LELs composed of large cells (high-grade LELs) but without a low-grade component (HG MALT lymphoma); and 3) diffuse large cell lymphoma without a low-grade MALT lymphoma component or LELs (DLCL). Twenty-two lymphomas were classified as low-grade MALT lymphomas, 16 as LG/HG MALT lymphomas, 10 as HG MALT lymphomas, and 12 as DLCL. B-cell immunophenotype was confirmed in all 55 cases in which immunophenotyping was performed. Low-grade LELs were seen in all low-grade MALT lymphomas, and CD20(L26) expression confirmed B-cell phenotype in the LELs in 20 of 20 cases. Clinical follow-up was available for 56 patients (range, 1-264 months; mean, 57 months). Actuarial analysis of disease-specific survival and relapse-free survival showed that clinical stage was highly statistically significant (P < 0.0001), whereas histologic type and grade approached statistical significance. Multivariate analysis showed that clinical stage was the only significant factor in relapse-free and disease-specific survival.

Non-random loss of chromosome 3 during transition of Helicobacter pylori-associated gastric MALT to B-cell MALT lymphoma revealed by fluorescence in situ hybridization

Acquired gastric mucosa-associated lymphoid tissue (MALT) accumulates as a result of long-standing Helicobacter pylori (H. pylori) infection and from this acquired MALT, low-grade B-cell MALT lymphoma may develop. Carcinogenesis is a multistep, multifactorial process involving the progressive accumulation of genetic changes. To determine whether numerical chromosomal alterations are involved in the transition of H. pylori-associated human gastric MALT to low-grade B-cell MALT lymphoma, frozen biopsy specimens prospectively obtained from H. pylori positive gastric MALT and gastric MALT lymphoma patients, as well as normal control patients (normal gastroscopy/gastric mucosal histology/H. pylori negative), were analyzed by fluorescence in situ hybridization (FISH). Fluorescent, directly labeled alpha-satellite DNA probes, specific for the centromeres of chromosomes 1, 3, 4, 11, 17 and Y were used in this study. The non-random loss of chromosome 3 was detected in two MALT patients and in all five MALT lymphoma patients. Trisomy 17 was detected in one MALT patient and one MALT lymphoma patient. Trisomy 1 was detected in a single MALT lymphoma patient as was trisomy 3. None of the MALT patients had trisomy 3 or trisomy 1. Monosomy 17 was noted in one MALT lymphoma patient. Clonal aneusomy was not observed in any patient for chromosomes Y, 4 or 11. These results suggest that the consistent loss of chromosome 3 may be an important genetic alteration in the transformation of H. pylori-associated gastric MALT into low-grade B-cell gastric MALT lymphoma.

Clinical features, treatment and outcome in a series of 93 patients with low-grade gastric MALT lymphoma

The purpose of this paper is to report the clinical characteristics and treatment outcome following different therapeutic approaches in a large series of patients with primary low-grade MALT lymphoma of the stomach. A total of ninety-three patients (median age 63 years) were reviewed. The patients were treated by different modalities (local treatment alone, combined treatment, chemotherapy, antibiotics alone); seven patients refused any treatment. The antibiotic-treated group of patients was prospectively followed with regular endoscopic biopsies, and their responses were histologically evaluated. The 5-years projected overall survival is 82% (95% C.I.; 67%-91%) in the series as a whole. Second tumors were observed in 21.5% of the patients in this series (95% CI 14%v to 31%). There was no apparent difference in overall survival and event-free survival between patients who received different treatments. In the antibiotic-treated group histologic regression of MALT lymphoma was documented in 67% of patients (95% CI 51% to 80%). In conclusion the indolent nature of the disease justifies a conservative approach. The use of antibiotics as first-line therapy may avert or at least postpone the indication for surgical resection in the majority of patients.

Lymphomas in Patients With Sjögren's Syndrome Are Marginal Zone B-Cell Neoplasms, Arise in Diverse Extranodal and Nodal Sites, and Are Not Associated With Viruses

The occurrence of non-Hodgkin's lymphoma (NHL) is the most serious complication of Sjögren's syndrome (SS). We performed a study of 16 NHLs occurring in patients with an underlying SS. These lymphomas arose not only in salivary glands (7 cases) but also in other mucosal extranodal sites (the stomach [4 cases], the lung [3 cases], the skin [3 cases], the buccal mucosa [1 case], the thymus [1 case]) and in nodal sites (8 cases). Low-grade marginal zone lymphomas (MZL) were diagnosed in 12 of the 16 patients, 9 of mucosa-associated lymphoid tissues (MALT) type in mucosal sites and 3 exclusively nodal. The 4 other patients presented with a high-grade B-cell lymphoma that was probably a histological transformation of an underlying low-grade MZL at least in 3 of the cases involving skin, stomach, and parotid, respectively. A t(14; 18) translocation was detected in 1 of 8 lymphomas tested. We detected serum anti-p53 antibodies in 2 of the 14 studied patients. p53 protein was detected in 1 of 11 lymphomas tested. LMP protein and Eber RNAs of Epstein-Barr virus (EBV) were not detected in the 16 NHL biopsies. Using polymerase chain reaction, EBV was never detected except in 1 of 4 parotid lymphomas. No human T-lymphotropic virus 1 or human herpes virus 8 DNAs were detected in NHL biopsies. None of the patients had hepatitis C virus infection found using serological methods. Chemotherapy was usually efficient. In conclusion, lymphomas occurring in patients with an underlying SS are in most cases MZL. These lymphomas are not associated with viruses known to be present in other types of lymphomas. Some of the translocations or mutations of oncogenes or antioncogenes described in other lymphomas are detected in SS-associated lymphomas.

Lymphomas in Patients With Sjögren's Syndrome Are Marginal Zone B-Cell Neoplasms, Arise in Diverse Extranodal and Nodal Sites, and Are Not Associated With Viruses

The occurrence of non-Hodgkin's lymphoma (NHL) is the most serious complication of Sjögren's syndrome (SS). We performed a study of 16 NHLs occurring in patients with an underlying SS. These lymphomas arose not only in salivary glands (7 cases) but also in other mucosal extranodal sites (the stomach [4 cases], the lung [3 cases], the skin [3 cases], the buccal mucosa [1 case], the thymus [1 case]) and in nodal sites (8 cases). Low-grade marginal zone lymphomas (MZL) were diagnosed in 12 of the 16 patients, 9 of mucosa-associated lymphoid tissues (MALT) type in mucosal sites and 3 exclusively nodal. The 4 other patients presented with a high-grade B-cell lymphoma that was probably a histological transformation of an underlying low-grade MZL at least in 3 of the cases involving skin, stomach, and parotid, respectively. A t(14; 18) translocation was detected in 1 of 8 lymphomas tested. We detected serum anti-p53 antibodies in 2 of the 14 studied patients. p53 protein was detected in 1 of 11 lymphomas tested. LMP protein and Eber RNAs of Epstein-Barr virus (EBV) were not detected in the 16 NHL biopsies. Using polymerase chain reaction, EBV was never detected except in 1 of 4 parotid lymphomas. No human T-lymphotropic virus 1 or human herpes virus 8 DNAs were detected in NHL biopsies. None of the patients had hepatitis C virus infection found using serological methods. Chemotherapy was usually efficient. In conclusion, lymphomas occurring in patients with an underlying SS are in most cases MZL. These lymphomas are not associated with viruses known to be present in other types of lymphomas. Some of the translocations or mutations of oncogenes or antioncogenes described in other lymphomas are detected in SS-associated lymphomas.

Eradication of Helicobacter pylori and regression of B-cell lymphoma

There is an increasing body of evidence implicating a causal association between Helicobacter pylori and the development of mucosa-associated lymphoid tissue (MALT) associated B-cell gastric lymphoma. Investigators have noted that almost all patients with H pylori-associated chronic gastritis develop lymphoid follicles. Some of these patients demonstrate infiltration of B cells and lymphoepithelial lesions typical of MALT lymphoma. When gastric tissue from patients with gastric B-cell lymphoma is analyzed for H pylori infection, the overwhelming majority of patients demonstrate this condition. Epidemiologic nested case-control studies have shown that patients with gastric non-Hodgkin's lymphoma are substantially more likely that matched controls to have H pylori infection. This situation may be analogous to the linkage between chronic Epstein-Barr virus and lymphoma. The mechanisms inducing the development of lymphoma are not clear, but it has been suggested that chronic infection with H pylori results in the stimulation of H pylori-responsive T cells which in turn activate B cells with the subsequent development of a mutation to a monoclonal B-cell population. Recent evidence indicates that cure of H pylori infection produces regression of MALT lymphoma within 3 to 12 months in approximately 75% of antibiotic-treated patients. Individual responsiveness remains unpredictable, however, and careful and prolonged endoscopic and histologic follow-up is needed. Large, well-controlled studies are necessary, however, to determine the duration of 'cure' and the appropriate setting for treatment.

Immunological and molecular classification of mucosa-associated lymphoid tissue lymphoma

Malignant B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) type is now considered to be a tumor of marginal zone cells of native or, more frequently, acquired MALT. The relationship of MALT lymphoma to the normal counterpart population is acknowledged by the revised European-American classification of lymphoid neoplasms (R.E.A.L.). It fits into the extranodal subtype of marginal zone lymphoma listed as a distinct entity in this recent classification scheme. A typical feature of this lymphoma type is a close lymphocyte-epithelium interaction as reflected by lymphoepithelial lesions. The immunophenotype is characterized by the expression of Sig and B-cell-associated antigens and by the lack of CD5 and CD10. Frequent occurrence of trisomy 3 has been reported. There is now overwhelming evidence that low-grade MALT lymphomas are subject to immunologic drive. In the stomach, the presence of Helicobacter pylori and locally activated T cells appears to be critical for the growth of neoplastic cells. This finding is of clinical significance since the eradication of H. pylori has been shown to reverse low-grade MALT lymphoma.