[Treatment of primary gastric lymphoma]

Stomach is the most common location of lymphoma in digestive tract, accounting for 50%-60% of gastrointestinal lymphomas. The most common histological types are low malignant mucosa-associated lymphoid tissue (MALT) lymphoma from non-Hodgkin lymphoma (NHL) and diffuse large B-cell and marginal zone B-cell lymphoma (DLBCL) from NHL. Chronic gastritis secondary to Helicobacter pylori(HP) infection has been considered a major predisposing factor for MALT lymphoma. At present, the most widely accepted initial therapy for localized disease is aimed at the eradication of HP using regimens combining antibiotics and proton-pump inhibitors. The irradiation has become the therapy of choice for patients with early stage MALT lymphoma without HP infection or with persistent lymphoma following antibiotic therapy. In all the patients with advanced disease, treatment options include chemotherapy and the use of monoclonal antibodies. Treatment of DLBCL in stomach is based on aggressive poly-chemotherapy that is usually combined with rituximab. The same guidelines followed for nodal aggressive lymphoma can also be applied to gastric lymphoma with aggressive histology as DLBCL. For localized stages (stages I( and II(), these guidelines suggest front-line therapy with 3 to 4 cycles of standard R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone) followed by radiotherapy. Advanced stage patients (stage IIII() usually undergo only 6 to 8 cycles of R-CHOP in order to obtain a complete remission rate. Nowadays surgery is limited to rare cases and radiotherapy combined or not with chemotherapy represents an effective therapeutic option ensuring long-term, organ-salvage benefits mainly in aggressive histological types.

[Clinicopathological features and prognostic analysis of 151 patients with primary extra-nodal non-Hodgkin's lymphoma]

OBJECTIVE

To evaluate the epidermiology, clinicopathological features and prognosis of primary extra-nodal non-Hodgkin's lymphoma (PE-NHL).

METHODS

The clinicopathological data of 151 patients diagnosed as PE-NHL in the First Affiliated Hospital of Jilin University between January 2007 and December 2011 were reviewed and analyzed.

RESULTS

The proportion of PE-NHL patients was 58.8% among all the non-Hodgkin's lymphoma cases, with the average age of 52 years, and the male/female ratio was 1.16:1. The most frequently involved site was the stomach (30.5%) followed by nose and sinuses (19.9%) and Waldeyer's ring (17.2%). The most common subtype was diffuse large B-cell lymphoma (DLBCL) (55.0%), followed by NK/T (18.5%) and extra-nodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) ( 13.2%). The distribution of clinical stages was as follows: stage I 20.5%, II 29.8%, III 29.1%, and IV 20.5%. Most nasal PE-NHL is in early stages, with a proportion of 76.7% in stages I & II. The 3-year overall survival rate was 73.2% and 3-year progression free survival rate was 46.6% in the PE-DLBCL patients. The International Prognosis Index (IPI) could be used to estimate the prognosis of PE-DLBCL well. Multivariate analysis showed that ESR and curative effect of the first treatment were independent prognostic factors for PE-DLBCL patients.

CONCLUSIONS

The incidence of PE-NHL is quite high, and the most common primary extra-nodal site is the gastro-intestinal tract and the most common subtype is diffuse large B-cell lymphoma. Risk groups based on IPI can indicate the prognosis of PE-DLBCL to some extent, but only the ESR and curative effect of the first treatment are confirmed to be independent risk factors.

[A case report of isolated marginal zone B cell lymphoma originating from the parapharyngeal space]

This is a case report of isolated marginal zone B cell lymphoma originating from the parapharyngeal space and reaching up to the side of skull base. There are no obvious clinical symptoms of the marginal zone B cell lymphoma originating in the parapharyngeal space, the imaging examination of which showed slightly blurred edge mass shadow with heterogeneous textures and no specificity. The pathological examination revealed a large number of lymphocyte proliferation, which was not specific yet. Immunohistochemistry may show the tumor was monoclonal and positive to CD20 and CD79a positive. Marginal zone B cell lymphoma originating in the parapharyngeal space is a rare tumor with no specific clinical symptoms or early signs, and is easily misdiagnosed. The diagnosis should be confirmed based on pathological and immunohistochemical examination, and the tumor can be treated by surgery combined with chemotherapy.

MALT lymphomas -Treated with chemotherapy or radiotherapy: Clinical Features, Prognostic factors and Survival

OBJECTIVE

MALT lymphomas are a group of extranodal indolent lymphomas that usually present as stage IE. To clarify clinical features, treatment alternatives and outcomes, we evaluated 38 patients treated with chemotherapy or radiotherapy between 2000 and 2011.

PATIENTS AND METHODS

MALT lymphoma patients identified according to WHO classification and treated at KCCC between 2000 and 2011 were included in this study. Demographic and clinical data are presented as means or medians. Overall survival was estimated using the Kaplan-Meier method. Survival rates were compared using the log-rank test. A p value < 0.05 was considered significant.

RESULTS

The median age of the patients was 49 years and the male to female ratio was 2:1. Gastric MALT accounted for 63% of all patients and the most common presenting symptom was abdomen pain and dyspepsia. The common extra gastric sites were salivary glands, lung and orbit. 90% of the patients presented with early stage disease. Two patients had history of pre-existing autoimmune disease. Even among patients who had failed prior antibiotic therapy for Helicobacter pylori, treatment with chemotherapy achieved good results with 5 year survival of 80%.

CONCLUSION

MALT lymphomas are indolent neoplasm's with excellent long term outcome. There is no significant difference in survival between gastric and extra-gastric MALT lymphoma.

KEYWORDS

MALT lymphoma, Gastric Neoplasm, H. pylori.

Diagnosis and treatment of Helicobacter pylori infection

National Danish guidelines for the diagnosis and treatment of Helicobacter pylori (Hp) infection have been approved by the Danish Society for Gastroenterology. All patients with peptic ulcer disease, gastric cancer, and MALT lymphoma should be tested for Hp. We also recommend testing in first degree relatives to patients with gastric cancer, in NSAID-naive patients, who need long-term NSAID therapy, and in patients presenting with dyspepsia and no alarm symptoms. Non-endoscoped patients can be tested with a urea-breath test or a faecal antigen test. Endoscoped patients can be tested with a rapid urease test. Proton pump inhibitor therapy should be stopped at least 1 week prior to Hp testing. All infected patients should be offered Hp eradication therapy. First-line treatment is 7-day triple therapy with a proton pump inhibitor and clarithromycine in combination with metronidazole or amoxicilline. Quadruple therapy for 2 weeks with bismuthsubsalicylate, tetracycline, metronidazole and a proton pump inhibitor is recommended in case of treatment failure. Hp testing should be offered to all patients after eradication therapy but is mandatory in patients with ulcer disease, noninvasive gastric cancer or MALT lymphoma. Testing after eradication should not be done before 4 weeks after treatment has ended.

Etiologic heterogeneity among non-Hodgkin lymphoma subtypes

Understanding patterns of etiologic commonality and heterogeneity for non-Hodgkin lymphomas may illuminate lymphomagenesis. We present the first systematic comparison of risks by lymphoma subtype for a broad range of putative risk factors in a population-based case-control study, including diffuse large B-cell (DLBCL; N = 416), follicular (N = 318), and marginal zone lymphomas (N = 106), and chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL; N = 133). We required at least 2 of 3 analyses to support differences in risk: (1) polytomous logistic regression, (2) homogeneity tests, or (3) dichotomous logistic regression, analyzing all 7 possible pairwise comparisons among the subtypes, corresponding to various groupings by clinical behavior, genetic features, and differentiation. Late birth order and high body mass index (>/= 35) kg/m(2)) increased risk for DLBCL alone. Autoimmune conditions increased risk for marginal zone lymphoma alone. The tumor necrosis factor G-308A polymorphism (rs1800629) increased risks for both DLBCL and marginal zone lymphoma. Exposure to certain dietary heterocyclic amines from meat consumption increased risk for CLL/SLL alone. We observed no significant risk factors for follicular lymphoma alone. These data clearly support both etiologic commonality and heterogeneity for lymphoma subtypes, suggesting that immune dysfunction is of greater etiologic importance for DLBCL and marginal zone lymphoma than for CLL/SLL and follicular lymphoma.

A unique case of IgD-only splenic marginal-zone lymphoma with mutated immunoglobulin genes: ontogenetic implications

Splenic marginal zone lymphoma (SMZL) is a rare indolent lymphoma subtype which accounts for less than 1% of all non-Hodgkin's lymphomas. We here report a unique case of IgD-only SMZL with mutated immunoglobulin variable region genes and discuss possible ontogenetic derivation.

[A case of H. pylori and API2-MALT1 gene-negative gastric mucosa-associated lymphoid tissue lymphoma with a carcinoma-like signet-ring cell lymphoepithelial lesion]

A 60-year-old woman presented in February 2003 with an ulcer on the lesser curvature of the anglus. The endoscopic biopsy specimens showed epithelial signet-ring cell associated with lymphoid infiltration, suggesting a diagnosis of gastric cancer. Histopathological examination confirmed the diagnosis of low-grade B-cell lymphoma of MALT with epithelial signet-ring cell lymphoepithelial lesion, which was negative for H. pylori and t (11;18) (q21;q21) translocation (API2-MALT1 gene). This case was treated with H. pylori eradication and additional radiation therapy, and the tumor was disappeared.

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

We report the remission of primary gastric lymphoma of the mucosa-associated lymphoid tissue (MALT) type in two immunocompromised pediatric patients. Patient 1, a 14-year-old boy in an immunocompromised state of unknown cause, complained of repeated abdominal pain. Examinations revealed gastric MALT with local invasion and lymph node involvement. Serum anti-Helicobacter pylori (H pylori) antibody was positive. H pylori eradication was abandoned due to its adverse effects. The MALT lesion spontaneously regressed over the next 24 months without any treatment for lymphoma. Patient 2, a 6-year-old boy, underwent cord blood transplantation for the treatment of adrenoleukodystrophy. He was administered immunosuppressants for graft-versus-host disease after transplantation. Nausea and hematochezia appeared and further examinations revealed gastric MALT with H pylori gastritis. Treatment consisting of medication for the H pylori infection alone eradicated the H pylori and completely resolved the patient’s MALT lesion, as well. Patients 1 and 2 were followed up over periods of 10 years and 3 years, respectively, without any signs of relapse. In conclusion, gastric lymphoma of the MALT type can be cured by conservative treatment even in immunocompromised pediatric patients.

Marginal zone lymphoma

Marginal zone lymphomas (MZLs) comprise 3 distinct entities: extranodal MZL of mucosa-associated lymphoid tissue (MALT), splenic MZL, and nodal MZL. Gastric MALT lymphoma is the most common extranodal MZL and often develops as a result of chronic Helicobacter pylori gastritis. Such cases frequently respond to antibiotics directed against H. pylori. Antigen-driven lymphomatous disease can also be seen in the association of Borrelia burgdorferi with MALT lymphoma of the skin, Chlamydia psittaci with MALT lymphoma of the ocular adnexa, Campylobacter jejuni with immunoproliferative disease of the small intestine, and hepatitis C with splenic MZL. This article discusses the pathogenesis and clinical features of MZL and the treatment options available to patients.

Molecular Cytogenetic Analysis of Chromosomal Breakpoints in the IGH, MYC, BCL6, and MALT1 Gene Loci in Primary Cutaneous B-cell Lymphomas

Chromosomal translocations affecting the IGH locus and various oncogene loci are recurrent in many types of systemic B-cell lymphomas. Hardly any data exist, however, on such translocations in primary cutaneous B-cell lymphomas (PCBCL). Here, a series of 29 PCBCL was investigated by interphase fluorescence in situ hybridization with probes for the IGH, MYC, BCL6, and MLT1 loci. None of the six follicle center cell lymphomas and nine marginal zone lymphomas showed evidence for any translocation affecting these loci. In contrast, 11 of 14 large B-cell lymphomas of the leg harbored breakpoints in at least one of the loci. Translocations involving the MYC locus were detected in six cases, five of them derived from a MYC/IGH juxtaposition and one from a translocation involving a non-IG gene partner. Rearrangements of the BCL6 locus were detected in five B-cell lymphomas of the leg, and involved IGH (two cases), IGL (one case), and non-IG genes (two cases). This study shows that large B-cell lymphomas of the leg display a pattern of chromosomal translocations similar to their systemic counterparts whereas primary cutaneous follicle center cell lymphomas and marginal zone lymphomas lack these typical chromosomal translocations.

The TRAF6 ubiquitin ligase and TAK1 kinase mediate IKK activation by BCL10 and MALT1 in T lymphocytes

The CARD domain protein BCL10 and paracaspase MALT1 are essential for the activation of IkappaB kinase (IKK) and NF-kappaB in response to T cell receptor (TCR) stimulation. Here we present evidence that TRAF6 ubiquitin ligase and TAK1 protein kinase mediate IKK activation by BCL10 and MALT1. RNAi-mediated silencing of MALT1, TAK1, TRAF6, and TRAF2 suppressed TCR-dependent IKK activation and interleukin-2 production in T cells. Furthermore, we have reconstituted the pathway from BCL10 to IKK activation in vitro with purified proteins of MALT1, TRAF6, TAK1, and ubiquitination enzymes including Ubc13/Uev1A. We find that a small fraction of BCL10 and MALT1 proteins form high molecular weight oligomers. Strikingly, only these oligomeric forms of BCL10 and MALT1 can activate IKK in vitro. The MALT1 oligomers bind to TRAF6, induce TRAF6 oligomerization, and activate the ligase activity of TRAF6 to polyubiquitinate NEMO. These results reveal an oligomerization --> ubiquitination --> phosphorylation cascade that culminates in NF-kappaB activation in T lymphocytes.

MALT1/paracaspase is a signaling component downstream of CARMA1 and mediates T cell receptor-induced NF-kappaB activation

T cell receptor (TCR) induces a series of signaling cascades and leads to activation of multiple transcription factors, including NF-kappaB. Although the mechanism of TCR-induced NF-kappaB activation is not fully understood, recent studies indicate that Bcl10 and CARMA1, two adaptor/scaffold proteins, play essential roles in mediating TCR-induced NF-kappaB activation. MALT1/paracaspase is a caspase-like protein that contains an N-terminal death domain, two Ig-like domains, and a C-terminal caspase-like domain. It binds to Bcl10 through its Ig-like domains and cooperates with Bcl10 to activate NF-kappaB. Recently, it has been shown that MALT1 is involved in mediating TCR signal transduction, leading to activation of NF-kappaB. In this study, we show that MALT1 is recruited into the lipid rafts of the immunological synapse following activation of the TCR and the CD28 coreceptor (CD3/CD28 costimulation). This recruitment of MALT1 is dependent on CARMA1 because CD3/CD28 costimulation failed to recruit MALT1 into lipid rafts in CARMA1-deficient T cells. In addition, we also found that MALT1 not only binds to Bcl10 directly, but also associates with CARMA1 in a Bcl10-independent manner. Therefore, MALT1, Bcl10, and CARMA1 form a trimolecular complex. Expression of a MALT1 deletion mutant containing only the N-terminal death domain and the two Ig-like domains completely blocked CD3/CD28 costimulation-induced, but not tumor necrosis factor-alpha-induced, NF-kappaB activation. Together, these results indicate that MALT1 is a crucial signaling component in the TCR signaling pathway.

Improved technique for fluorescence in situ hybridisation analysis of isolated nuclei from archival, B5 or formalin fixed, paraffin wax embedded tissue

Fluorescence in situ hybridisation (FISH) is an effective method to detect chromosomal alterations in a variety of tissue types, including archived paraffin wax embedded specimens fixed in B5 or formalin. However, precipitating fixatives such as B5 have been known to produce unsatisfactory results in comparison with formalin when used for FISH. This study describes an effective nuclear isolation and FISH procedure for B5 and formalin fixed tissue, optimising the nuclear isolation step and nuclei pretreatments using tonsil and mantle cell lymphoma specimens. The protocol presented can be used to isolate nuclei and perform FISH on B5 or formalin fixed, paraffin wax embedded samples from a variety of tissue types.

Bimp1, a MAGUK family member linking protein kinase C activation to Bcl10-mediated NF-kappaB induction

Bcl10 and MALT1, products of distinct chromosomal translocations in mucosa-associated lymphoid tissue lymphoma, cooperate in activating NF-kappaB. Mice lacking Bcl10 demonstrate severe immunodeficiency associated with failure of lymphocytes to activate nuclear factor kappaB (NF-kappaB) in response to antigen receptor stimulation and protein kinase C activation. We characterize Bimp1, a new signaling protein that binds Bcl10 and activates NF-kappaB. Bimp1-mediated NF-kappaB activation requires Bcl10 and IkappaB kinases, indicating that Bimp1 acts upstream of these mediators. Bimp1, Bcl10, and MALT1 form a ternary complex, with Bcl10 bridging the Bimp1/MALT1 interaction. A dominant negative Bimp1 mutant inhibits NF-kappaB activation by anti-CD3 ligation, phorbol ester, and protein kinase C expression. These results suggest that Bimp1 links surface receptor stimulation and protein kinase C activation to Bcl10/MALT1, thus leading to NF-kappaB induction.

Inflammatory pseudotumor of the submandibular gland: report of a case presenting with autoimmune disease-like clinical manifestations

We report a rare case of inflammatory pseudotumor arising in the submandibular gland, which presented with autoimmune disease-like clinical manifestations. A 70-year-old Japanese man developed masses in both submandibular regions. Laboratory tests revealed polyclonal hypergammaglobulinemia, high titers of antinuclear antibody, and a positive thyroid test. Histologically, the lesion was composed of multiple nodules separated by thick fibrous bands and contained a few atrophic lymphoid follicles and residual ductal structures. At higher magnification, the nodules contained numerous mature plasma cells mixed with myofibroblasts, lymphocytes, and histiocytes. Occasionally, the myofibroblasts were arranged in poorly formed fascicles and in a storiform pattern. Polymerase chain reaction analysis failed to demonstrated the rearrangement of the immunoglobulin heavy-chain gene. The patient was free of disease after 72 months follow-up. Marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) type arising from salivary glands occasionally showed prominent plasma cell differentiation. The present case indicates that inflammatory pseudotumor should be added to the list of different diagnoses for mucosa-associated lymphoid tissue-type lymphoma of the salivary glands.

Complete remission of generalized relapsed extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue type of the gastrointestinal tract after high-dose chemotherapy and autologous peripheral stem cell transplantation

Due to their homing properties, extranodal marginal zone B-cell lymphoma (MZBL) of mucosa-associated lymphoid tissue (MALT) type remain localized for long periods of time, and therefore have an excellent prognosis. However, if generalization and/or transformation into a diffuse large-cell lymphoma occurs, the prognosis deteriorates and no established treatment concepts are yet available. We report about a 57-year-old female patient with relapsed transformed stage-IV extranodal MZBL of MALT type of the entire gastrointestinal tract who was successfully treated using salvage chemotherapy followed by BEAM conditioning [BCNU 1,3-bis-2-(chloroethyl-1-nitrosourea), etoposide, cytosine arabinoside, and melphalan] and autologous peripheral stem cell transplantation. Follow-up revealed a sustained complete remission for 22 months.

Incidence and subtype specificity of API2-MALT1 fusion translocations in extranodal, nodal, and splenic marginal zone lymphomas

The t(11;18)(q21;q21) is thought to represent an important primary event in the development of marginal zone lymphomas, although an accurate estimation of the frequency and distribution of this genetic alteration among nodal, splenic, and extranodal marginal zone lymphoma types has yet to be determined. Recently, molecular genetic studies have shown that this translocation results in the fusion of the API2 gene on chromosome 11 and a novel gene termed MALT1 on chromosome 18. To investigate the incidence of API2-MALT1 fusion transcripts among marginal zone lymphomas and to determine possible marginal zone lymphoma subtype associations, we used reverse transcriptase-polymerase chain reaction to analyze RNAs extracted from frozen tissue samples of 99 marginal zone lymphomas. Fifty-seven involved diverse extranodal sites including 14 stomach, 11 lung, 7 orbit, 7 parotid, 5 thyroid, 5 lacrimal gland, 3 small intestine, 2 large intestine, 1 kidney, 1 paraspinal region and 1 skin. Twenty-one primary splenic and twenty-one primary nodal marginal zone lymphomas were also studied. API2-MALT1 fusion transcripts were detected in 12 of 57 extranodal marginal zone lymphomas (21%), but in none of the nodal or splenic cases. The cDNA sequences of the fusion transcripts were determined, revealing variation in the coding sequence fusion point for both API2 and MALT1. The findings suggest that t(11;18)(q21;q21) is restricted to extranodal marginal zone lymphomas and that these tumors have distinct genetic etiologies in comparison with their splenic and nodal counterparts.