Development Of Mucosa-associated Lymphoid Tissue Lymphoma Research Articles

Thymic mucosa-associated lymphoid tissue lymphoma in a patient with Sjögren’s syndrome with cutaneous vasculitis

Introduction. The association between Sj?gren?s syndrome (SS) and the development of lymphoma is well known. The prevalence of lymphoma in patients with SS is 5%. Mucosa-associated lymphoid tissue (MALT) lymphoma is the most common lymphoma type in patients with SS. It is common for MALT lymphoma to develop in the stomach, while it is extremely rare in the thymus. Case report. We present a 61-year-old Caucasian male patient with primary SS, cutaneous vasculitis, and thymic MALT lymphoma. The patient had a two-year history of diffuse cutaneous palpable purpura on legs, intermittently enlarged left parotid gland, and dry mouth. The results of Schirmer?s test were positive, labial salivary glands biopsy revealed a focus score ? 1, serology testing showed positive anti-Ro/SS-A and anti-La/SS-B antibodies, while skin biopsy findings revealed leukocytoclastic vasculitis. Diagnosis of primary SS with extraglandular cutaneous manifestations was confirmed. Cryoglobulinemia (Cg) and monoclonal gammopathy (MG) were detected, which increased the suspicion of hematological malignancy, and additional diagnostic procedures were performed. Computed tomography of the chest revealed an enlarged, multicystically altered anterior mediastinal mass. A thymectomy was performed through video-assisted thoracic surgery. Histological findings of the tissue confirmed the presence of tumor tissue consistent with MALT lymphoma in the thymus. Induction therapy with pulse doses of glucocorticoids was applied for three days, which was continued with medium doses of the drug. The doses were gradually reduced, and hydroxychloroquine was introduced. This has shown to be an effective therapy against features of SS. Postoperative local radiotherapy was performed. Conclusion. In SS patients with CV and in the presence of Cg and MG, attention should also be paid to the eventual development of MALT lymphoma, including the rare localization in the thymus.

Laparoscopic distal gastrectomy for synchronous adenocarcinoma, diffuse large B cell lymphoma and gastrointestinal stromal tumor in the stomach: a case report

BackgroundSynchronous lymphoma and adenocarcinoma are occasionally detected in the stomach. Gastrointestinal stromal tumor (GIST) and adenocarcinoma are sometimes seen simultaneously in the stomach. However, we rarely observe synchronous adenocarcinoma, lymphoma, and GIST in the stomach, and there are few reports on cases with these three lesions.Case presentationThis is a case report of a 71-year-old man who had a laparoscopic distal gastrectomy and lymphadenectomy for three gastric tumors. Preoperative diagnoses were early adenocarcinoma and mucosa-associated lymphoid tissue (MALT) lymphoma in the stomach, but final diagnosis was synchronous adenocarcinoma, diffuse large B cell lymphoma (DLBCL), and GIST. Helicobacter pylori (H. pylori) is highly involved in the development of DLBCL and MALT lymphoma in the stomach. Gastric adenocarcinoma is partially involved in chronic gastritis with atrophy and intestinal metaplasia caused by H. pylori infection. Indeed, a rapid urease test was found positive in this case. Therefore, we prescribed medicine to eliminate H. pylori after gastrectomy.ConclusionThis is the first case report where a patient underwent minimally invasive laparoscopic gastrectomy for synchronous adenocarcinoma, DLBCL and GIST in the stomach, although one patient who underwent open gastrectomy for synchronous adenocarcinoma, MALT lymphoma and GIST was previously reported.

Low Mutational Burden of Extranodal Marginal Zone Lymphoma of Mucosa-Associated Lymphoid Tissue in Patients with Primary Sjogren's Syndrome.

Simple SummaryPatients with primary Sjogren’s syndrome (pSS) are at risk of developing extranodal marginal zone lymphoma (ENMZL) of the mucosa-associated lymphoid tissue (MALT) in the parotid glands. The genetic mechanism underlying development of MALT lymphoma in the context of pSS is unknown. The aim of our study was to define the genomic landscape of pSS-associated MALT lymphoma. For 17 localized pSS-associated MALT lymphomas, we analyzed the presence of nonsynonymous mutations, copy number alterations (CNAs) and MALT1 translocations. pSS-associated MALT lymphomas were characterized by a low mutational load (median number of nonsynonymous somatic variants per case was 7, range 2–78) and a limited number of CNAs. Unlike the recurrent genomic aberrations observed in MALT lymphoma, which were not associated with pSS, pSS-associated MALT lacked a clear lymphoma-related profile. The data suggest that localized pSS-associated MALT lymphomas are a distinct type of ENMZL, which are genomically stable and most likely depend on a stimulatory micro-environment.Patients with primary Sjogren’s syndrome (pSS) are at risk of developing extranodal marginal zone lymphoma (ENMZL) of the mucosa-associated lymphoid tissue (MALT) in the parotid glands. Unlike recurrent genomic aberrations observed in MALT lymphoma, which were not associated with pSS (non-pSS), it is unknown which somatic aberrations underlie the development of pSS-associated MALT lymphomas. Whole-exome sequencing was performed on 17 pSS-associated MALT lymphomas. In total, 222 nonsynonymous somatic variants affecting 182 genes were identified across the 17 cases. The median number of variants was seven (range 2–78), including three cases with a relatively high mutational load (≥24/case). Out of 16 recurrently mutated genes, ID3, TBL1XR1, PAX5, IGLL5 and APC are known to be associated with lymphomagenesis. A total of 18 copy number alterations were detected in eight cases. MALT1 translocations were not detected. With respect to outcome, only two cases relapsed outside of the salivary glands. Both had a high mutational load, suggesting a more advanced stage of lymphoma. The low mutational load and lack of a clear lymphoma-related mutation profile suggests that localized pSS-associated MALT lymphomas are genomically more stable than non-pSS MALT lymphomas and most likely depend on a stimulatory micro-environment.

CCR6 activation links innate immune responses to mucosa-associated lymphoid tissue lymphoma development.

The genesis of extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) is driven by oncogenic co-operation among immunological stimulations and acquired genetic changes. We previously identified recurrent CCR6 mutations in MALT lymphoma, with majority predicted to result in truncated proteins lacking the phosphorylation motif important for receptor desensitization. Functional consequences of these mutational changes, the molecular mechanisms of CCR6 activation and how this receptor signaling contributes to MALT lymphoma development remain to be investigated. In the present study, we demonstrated that these mutations impaired CCR6 receptor internalization and were activating changes, being more potent in apoptosis resistance, malignant transformation, migration and intracellular signaling, particularly in the presence of the ligands CCL20, HBD2 (human b defensin 2) and HD5 (human a defensin 5). CCR6 was highly expressed in malignant B cells irrespective of the lymphoma sites. HBD2 and CCL20 were constitutively expressed by the duct epithelial cells of salivary glands, and also those involved in lymphoepithelial lesions (LEL) in salivary gland MALT lymphoma. While in the gastric setting, HBD2, and HD5, to a less extent CCL20, were highly expressed in epithelial cells of pyloric and intestinal metaplasia respectively including those involved in LEL, which are adaptive responses to chronic Helicobacter pylori infection. These findings suggest that CCR6 signaling is most likely active in MALT lymphoma, independent of its mutation status. The observations explain why the emergence of malignant B cells and their clonal expansion in MALT lymphoma are typically around LEL, linking the innate immune responses to lymphoma genesis.

Synchronous development of intrahepatic cholangiocarcinoma and MALT lymphoma of the liver with chronic B-viral hepatitis

Background: Hepatic mucosa-associated lymphoid tissue (MALT) lymphoma is a very rare disease, accounting for less than 0.1% of liver malignancies, and thus the diagnosis may be challenging. Although there have been many reported cases of synchronous development of intrahepatic cholangiocarcinoma (ICC) and hepatocellular carcinoma usually developed in patients with hepatitis-related liver cirrhosis, a case of synchronous development of ICC and MALT lymphoma of the liver has not been reported in the literature yet.

Helicobacter pylori cagA status and gastric mucosa-associated lymphoid tissue lymphoma: a systematic review and meta-analysis

BackgroundRecent studies have investigated the role of Helicobacter pylori infection in the development of gastric mucosa-associated lymphoid tissue (MALT) lymphoma. It is estimated that approximately 0.1% of people infected with H. pylori develop gastric MALT lymphoma. However, the role of the CagA antigen, the highest causative agent of H. pylori, in increasing the risk of gastric MALT lymphoma remains unclear and controversial. A systematic review and meta-analysis were conducted to evaluate the effect of cagA status on the development of gastric MALT lymphoma.MethodsAll articles evaluating the status of the cagA gene in the development of gastric MALT lymphoma were collected using systematic searches in online databases, including PubMed, Scopus, Embase, and Google Scholar, regardless of publication date. The association between cagA and gastric MALT lymphoma was assessed using the odds ratio (OR) summary. In addition, a random-effects model was used in cases with significant heterogeneity.ResultsA total of 10 studies met our inclusion criteria, among which 1860 patients participated. No association between cagA status and the development of MALT lymphoma (extranodal marginal zone B-cell lymphoma) was found in this study (OR 1.30; 0.906–1.866 with 95% CIs; I2: 45.83; Q-value: 12.92). Surprisingly, a meaningful association was observed between cagA status and diffuse large B-cell lymphoma (OR 6.43; 2.45–16.84 with 95% CIs). We also observed an inverse association between vacA and gastric MALT lymphoma risk (OR 0.92; 0.57–1.50 with 95% CIs).ConclusionsIt seems that the infection with cagA-positive H. pylori strains does not have a meaningful effect on the gastric MALT lymphoma formation, while translocated CagA antigen into the B cells plays a crucial role in the development of diffuse large B-cell lymphoma.

Recent Advances in the Genetic of MALT Lymphomas.

Simple SummaryMucosa-associated lymphoid tissue (MALT) lymphoma is the most common subtype of marginal zone lymphomas. These B-cell neoplasms may arise from many organs and usually have an indolent behavior. Recurrent chromosomal translocations and cytogenetic alterations are well characterized, some of them being associated to specific sites. Through next-generation sequencing technologies, the mutational landscape of MALT lymphomas has been explored and available data to date show that there are considerable variations in the incidence and spectrum of mutations among MALT lymphoma of different sites. Interestingly, most of these mutations affect several common pathways and some of them are potentially targetable. Gene expression profile and epigenetic studies have also added new information, potentially useful for diagnosis and treatment. This article provides a comprehensive review of the genetic landscape in MALT lymphomas.Mucosa-associated lymphoid tissue (MALT) lymphomas are a diverse group of lymphoid neoplasms with B-cell origin, occurring in adult patients and usually having an indolent clinical behavior. These lymphomas may arise in different anatomic locations, sharing many clinicopathological characteristics, but also having substantial variances in the aetiology and genetic alterations. Chromosomal translocations are recurrent in MALT lymphomas with different prevalence among different sites, being the 4 most common: t(11;18)(q21;q21), t(1;14)(p22;q32), t(14;18)(q32;q21), and t(3;14)(p14.1;q32). Several chromosomal numerical abnormalities have also been described, but probably represent secondary genetic events. The mutational landscape of MALT lymphomas is wide, and the most frequent mutations are: TNFAIP3, CREBBP, KMT2C, TET2, SPEN, KMT2D, LRP1B, PRDM1, EP300, TNFRSF14, NOTCH1/NOTCH2, and B2M, but many other genes may be involved. Similar to chromosomal translocations, certain mutations are enriched in specific lymphoma types. In the same line, variation in immunoglobulin gene usage is recognized among MALT lymphoma of different anatomic locations. In the last decade, several studies have analyzed the role of microRNA, transcriptomics and epigenetic alterations, further improving our knowledge about the pathogenic mechanisms in MALT lymphoma development. All these advances open the possibility of targeted directed treatment and push forward the concept of precision medicine in MALT lymphomas.

Low Mutational Burden of Extra Nodal Marginal Zone Lymphoma of Mucosa-Associated Lymphoid Tissue in Patients with Primary Sjogren's Syndrome

Background: Primary Sjogren's syndrome (pSS) is an autoimmune disease characterized by chronic inflammation of the exocrine glands. Patients with pSS are at increased risk of developing extra nodal marginal zone lymphoma of the mucosa-associated lymphoid tissue (MALT) type, predominantly in the salivary glands. The presence of cryoglobulinemia, low C4 levels and salivary gland enlargement, are important risk factors for lymphoma development in pSS. Although lymphoma associated mutations have been described in circulating B-cells of patients with pSS associated cryoglobulinemia, it is unknown which somatic aberrations underlie the development of pSS-associated MALT lymphomas. The aim of the current study was to define the genomic landscape of pSS salivary gland MALT lymphomas. Identification of specific recurrent mutations or copy number aberrations and defining the affected pathways would help to understand the mechanisms by which intra-epithelial B-cells undergo malignant transformation.Methods: Whole exome sequencing was performed on 14 fresh frozen and 3 paraffin embedded MALT tissue samples of pSS patients at the University Medical Center Groningen (UMCG). Matched peripheral white blood cell samples were available for 12 patients and were used as germline controls. Fluorescence in situ hybridization was performed for the detection of MALT1 translocations.Results: Presence of a clonal B-cell population, indicative of a MALT lymphoma was confirmed by IgH PCR (BIOMED-2) for all patients. Whole exome sequencing resulted in a median target coverage of 130x, ranging from 84-163. More than 90% of the target regions had a coverage of >50x. In total we identified 232 somatic mutations in 184 genes. Three cases had a relatively high mutational load (>25 / case), while the median number of mutations in the remaining 14 cases was 7. Across the 17 cases there were 18 recurrently mutated genes. PRKD1, associated with malignant epithelial tumor of the salivary glands, was the most frequently mutated gene (six cases). Besides PRKD1, five additional recurrently mutated genes are also involved in epithelial surface and/or extracellular matrix (MAMDC4, COL14A1, CAMSAP3, TMEM2 and MUC4). Five genes, all with mutations in two cases, were shown to be associated with lymphomagenesis (ID3, TBL1XR1, PAX5, IGLL5, APC). A total of 18 copy number alterations (CNAs) were detected in 8 of the 14 evaluable cases, with gains of part of chromosomes 2 and 19, and loss of chromosome 6 each being detected in two cases. With respect to outcome, only 2 cases with high mutational load relapsed outside of the salivary glands, suggesting a more advanced stage of lymphoma.Conclusion: The low mutational load and lack of a clear lymphoma related gene signature suggests that localized pSS MALT lymphomas are genetically stable and most likely depend on the inflammatory state of the micro-environment. Only those cases characterized by higher mutational load showed a relapse-remitting disease, as is typical for indolent lymphoma. These observations could be translated to the clinical setting and potentially have value as biomarker for identification of patients with a more aggressive disease. Confirmation in larger cohorts are required to confirm this potential association. This study also paves way for treatment strategies targeting the micro-environment. DisclosuresNo relevant conflicts of interest to declare.

The TLR4–TRIF–type 1 IFN–IFN-γ pathway is crucial for gastric MALT lymphoma formation after Helicobacter suis infection

SummaryHelicobacter suis, a zoonotic infection-related bacterium, can induce gastric mucosa-associated lymphoid tissue (MALT) lymphoma in humans and animals. Recently, we reported that the formation of gastric MALT lymphoma after H. suis infection is induced by interferon (IFN)-γ activation. Here, we revealed that activation of the Toll-like receptor (TLR) 4–Toll/IL-1 receptor domain-containing adapter-inducing interferon-β (TRIF) pathway after H. suis infection is associated with the production of type 1 IFNs (IFN-α, IFN-β) by gastric epithelial cells. Additionally, these type 1 IFNs interact with type 1 IFN receptors on gastric B cells, facilitating the secretion of IFN-γ and the activation of which is enhanced by positive feedback regulation in B cells. These results suggest that the TLR4–TRIF-type 1 IFN–IFN-γ pathway is crucial in the development of gastric MALT lymphoma after H. suis infection and may, therefore, represent a therapeutic target for the prevention of this condition.

Immunomodulatory treatment for mucosa‐associated lymphoid tissue lymphoma (MALT lymphoma)

The pathogenesis of mucosa-associated lymphoid tissue (MALT) lymphoma has been characterized as a dynamic process driven by lymphoma cell dependency on T-cell signaling, chronic antigenic stimulation of marginal zone B-cells and activation of the nuclear factor-kappa B signaling pathway. This concept is underlined by the strong causal connection of chronic Helicobacter pylori associated gastritis and MALT lymphoma development based on perpetual auto-antigenic stimulation of Helicobacter pylori-specific T-cells, but also its association with further potential infectious triggers and autoimmune disorders for extragastric lymphoma sites. Thus, given the dependency of MALT lymphoma cells on the tumor microenvironment, this specific entity appears highly suitable for immunomodulatory treatment strategies. Several approaches have been assessed in the last years including promising data on immunomodulatory agents "IMiDs" thalidomide and lenalidomide, macrolide antibiotics and antibodies. The aim of the present review is to discuss rationales for immunomodulatory therapies in MALT lymphoma and to present the statu quo on immunomodulatory and therefore chemotherapy-free treatment strategies for these patients.

Myeloid-Derived Suppressor Cells and γδT17 Cells Contribute to the Development of Gastric MALT Lymphoma in H. felis-Infected Mice.

Helicobacter-induced chronic inflammation and immune disorders are closely associated with the development of gastric mucosa-associated lymphoid tissue (MALT) lymphoma. Myeloid-derived suppressor cells (MDSCs) exhibit strong immunosuppressive properties and promote the growth of various solid tumors. However, the role of MDSCs in the development of MALT lymphoma has not been elucidated so far. We detected significant infiltration and enrichment of MDSCs in patients with MALT lymphoma, as well in Helicobacter felis-infected mouse model of gastric MALT lymphoma. In addition, the expression of arginase-1 and inducible nitric oxide synthase was significantly elevated both in gastric MALT lymphoma tissues and H. felis-infected stomach. Persistent H. felis infection closely reproduced the development of gastric MALT lymphoma and was accompanied by increased numbers of γδT17 cells. Accumulation of γδT17 cells was also validated in the human gastric MALT lymphoma tissues. Furthermore, the elevated cytokines interleukin-23 and interleukin-1β, as well as chemokines CCL20/CCR6, may be involved in the accumulation of γδT17 cells and the subsequent immunosuppression. These findings highlight the role of MDSCs and γδT17 cells in immune dysregulation during gastric MALT lymphoma development and their potential as therapeutic targets.

Atypical Lymphoid Proliferations and Clonality in Helicobacter-associated Inflammatory Infiltrates in Children.

Helicobacter infection is considered the major predisposing factor for gastric mucosa-associated lymphoid tissue (MALT) lymphoma with initial infection likely occurring in childhood. Primary gastric MALT lymphoma most commonly occurs in patients older than 50 years which is attributed to the lengthy chronic infection time required before the development of MALT lymphoma. Our study analyzes the histologic features and presence of immunoglobulin heavy chain (IGH) clonality in Helicobacter-associated chronic gastritis (62 cases) and Helicobacter-negative chronic gastritis (17 cases) biopsies within the pediatric population, diagnosed between 1996 and 2018. Helicobacter-associated gastritis was more likely to show active inflammation (P=0.01), with no significant difference in number of germinal centers or the strength, linear property, or depth of the inflammatory infiltrate. In total, 47% (29/62) of the Helicobacter-associated cases had at least 1 lymphoepithelial lesion, equivocal or definitive (a modified Wotherspoon score of 3 to 5), compared with 24% (4/17) of the Helicobacter-negative cases (P=0.5). All cases with lymphoepithelial lesions were assessed for IGH clonality, showing the presence of monoclonality in 27% (8/30) of evaluable cases. None of our patients were diagnosed with gastric lymphoma within available follow-up data. Although 4% of our cases could be considered MALT lymphoma in an adult patient based on prominent lymphoepithelial lesions and IGH monoclonality, caution is advised when diagnosing lymphoma in the pediatric population given the good prognosis of Helicobacter-associated gastritis in this age group. It is unclear if these monoclonal lymphoid proliferations require close follow-up.

2669 Mucosa-Associated Lymphoid Tissue Lymphoma: Crossing the Borders!

INTRODUCTION: Mucosa-associated lymphoid tissue (MALT) lymphoma or MALTomas are responsible for half of the primary gastric lymphomas and up to 8% of B-cell lymphomas. It mostly affects patients in their 5th or 6th decade of life. MALT lymphoma is well known to remain localized in the stomach and to follow a benign course. Despite that gastric MALToma is well defined in the literature, it is rather uncommon to present as a peri-pancreatic mass. Herein, we present the case of a patient with an incidental peri-pancreatic mass diagnosed as an aggressive form of MALT lymphoma. CASE DESCRIPTION/METHODS: A 76-year-old male with hypertension presented to the gastroenterology clinic for the evaluation of peri-pancreatic mass incidentally found during computed tomography (CT) scan performed for renal colic. Physical examination was remarkable for an epigastric fullness with no tenderness. Laboratory tests were remarkable for iron deficiency anemia. CT showed a 7 cm ill-defined soft tissue mass within the pancreaticoduodenal groove abutting the pancreatic head and encasing the gastroduodenal artery suspicious for a pancreatic neoplasm (Figure 1). Endoscopic ultrasound (EUS) showed a hypoechoic heterogeneous mass arising from the gastric wall in close proximity to the pancreas (Figure 2). EUS-guided biopsies were consistent with extra-nodal marginal zone lymphoma of MALT (Figure 3). Gastric biopsies confirmed the presence of MALToma and revealed positive Helicobacter Pylori (HP) infection. Staging workup confirmed extensive bone marrow as well as para-aortic, mediastinal and paratracheal lymph node involvement. The patient received curative HP treatment and was started on bendamustine and rituximab. DISCUSSION: The stomach is the most commonly affected organ by MALT lymphoma. Helicobacter Pylori is a major precursor for the development of gastric MALT lymphoma as up to 90% of affected patients show H.Pylori on stomach biopsies. Chronic HP infection leads to lymphoid tissue proliferation within the stomach and progression towards lymphoma. In this setting, the course is usually indolent with the disease usually confined to the stomach but aggressive tumor behavior has been reported. HP antibiotic eradication remains the first line therapy for early-stage HP positive gastric MALT lymphoma. In other instances, a patient-tailored approach is recommended based on the stage, involved site, HP status and clinical characteristics. Therapeutic options include radiation therapy, chemotherapy and surgery accordingly.

Expression of miRNA-21 in mucosa-associated lymphoid tissue lymphomas and its relationship with CHOP regimen

Objective To investigate the expression of miRNA (miR-21) in mucosa-associated lymphoid tissue(MALT) lymphomas and its relationship with the effects in CHOP regimen. Methods Lymph gland tissues and preoperative peripheral blood of 52 patients pathologically diagnosed with MALT lymphoma in Department of Hematology of Affiliated Hospital of Hebei University of Engineering from January 2015 to December 2017 were collected; meanwhile, 10 tissues from patients with lymphadenitis and 20 peripheral serum from healthy examination patients were also collected. Quantitative real-time polymerase chain reaction (qPCR) was used to compare the lymph gland tissues in MALT lymphoma patients and lymphadenitis patients, and the expression of miR-21 in peripheral serum of MALT lymphoma and healthy people. The selected 20 cases of MALT lymphoma were given CHOP regimen treatment for 6 cycles, and then the efficiency and inefficiency were compared; at the same time, the expression of miR-21 in peripheral serum of the patients in the effective group was detected. Results The relative expression of miR-21 of lymph node tissues in lymphadenitis patients and MALT lymphoma patients was 1.03±0.12 and 4.53±0.73 respectively, and the relative expression of miR-21 in preoperative peripheral serum of healthy people and MALT lymphoma patients was 0.83±0.04 and 3.87±0.21 respectively, and the differences were statistically significant (P= 0.047, P= 0.044). After 6 cycles of CHOP regimen, the total effect rate of MALT lymphoma was 70% (14/20), and the relative expression of miR-21 in preoperative and postoperative peripheral serum for the patients who obtained the effective results after CHOP regimen was 3.95±0.08 and 1.62±0.41, and the differences were statistically significant (P= 0.035). Conclusions The expression of miR-21 has a certain correlation with the occurrence and development of MALT lymphoma. Furthermore, the serum miR-21 expression may be related to the effect of CHOP regimen chemotherapy in MALT lymphoma. Key words: Mucosa associated-lymphoid tissue lymphoma; miRNA-21; CHOP regimen; Treatment outcome

Germinal centres in diagnostic labial gland biopsies of patients with primary Sjögren’s syndrome are not predictive for parotid MALT lymphoma development

ObjectivePatients with primary Sjögren’s syndrome (pSS) have an increased risk of developing non-Hodgkin’s lymphoma (NHL), particularly parotid gland mucosa-associated lymphoid tissue (MALT) lymphomas. Presence of germinal centres (GCs) in labial...

FcRL4+ B-cells in salivary glands of primary Sjögren's syndrome patients

Fc receptor-like protein 4 (FcRL4) is normally expressed on a small subset of mucosa-associated B-cells, as well as on mucosa-associated lymphoid tissue (MALT) lymphoma B-cells. Primary Sjögren's syndrome (pSS) patients have an increased risk of developing MALT lymphomas, preferentially in the parotid glands. For this reason we studied here by immunohistochemistry and mRNA analysis whether FcRL4 expressing B-cells are present in salivary gland tissue (labial and parotid) of pSS patients (n = 54) and non-pSS sicca patients (n = 16) and whether parotid gland MALT lymphomas in pSS patients (n = 49) also express this receptor. We also studied the effect of treatment (rituximab and abatacept) on the presence of FcRL4+ B-cells, and whether numbers in labial gland biopsies at time of diagnosis of pSS can predict whether patients are at risk for MALT lymphoma development.We demonstrate that FcRL4+ cells are present in salivary gland tissue of pSS patients where they are closely associated with ductal epithelial cells forming lymphoepithelial lesions. The glandular FcRL4+ cells are highly proliferative, genuine PAX5+ B-cells. These FcRL4+ B-cells are far more frequent in parotid gland than in labial gland tissue (p = 0.003). We further show that expression of FcRL4 is present in pSS-related parotid MALT lymphomas. The FcRL4 mRNA expression level in parotid MALT lymphoma is increased compared to parotid gland tissue of pSS patients without lymphoma (p = 0.017). However, numbers of FcRL4+ B-cells in labial gland biopsies taken at the time of pSS diagnosis, are not predictive for later development of MALT lymphoma. Reduction of parotid gland FcRL4+ B-cells by rituximab, but not abatacept is accompanied by restoration of the glandular epithelium, illustrating the crosstalk between these B-cells with the ductal cells.In conclusion, intraepithelial FcRL4+ B-cells are present in the salivary glands of pSS patients. These cells are likely involved in the epithelial changes seen in pSS. Their enrichment in parotid glands may explain why MALT lymphomas in pSS patients preferentially develop at this specific location.

An analysis of IgG4‐related ocular disease among idiopathic orbital inflammations and mucosa‐ associated lymphoid tissue lymphoma

PurposeTo determine the proportion of idiopathic orbital inflammation (IOI) and mucosa‐associated lymphoid tissue (MALT) lymphoma accounted for by immunoglobulin (Ig) G4‐related orbital disease (ROD) using domprehensive criteria and To report the clinicopathological characteristics of patients with ocular MALT lymphoma with IgG4‐positive ells.MethodsA retrospective histopathological review and clinical case series. 49 patients from January 2005 through August 2015 were included. 20 cases of biopsy‐confirmed IOI, 29 cases of biopsy‐confirmed MALT lymphoma. Immunohistochemistry with IgG and IgG4 immunostaing. MALT lymphoma with IgG4 positive plasma cells were included when the IgG4/IgG ratio was 40% and IgG4 count was over 10/HPF. Histopathologic features, demographic and clinical data, radiologic findings, treatment and follow‐up information for each patient were analysed.ResultsPossible IgG4‐ROD accounted for 50.0% of cases originally diagnosed as IOI and 41.38% of cases originally diagnosed as MALT lymphoma. IgG4 positive MALT lymphoma group has contralateral IgG4 positive chronic inflammation lesion (p = 0.007). Relapse rate is higher than IgG4‐ unrelated group (p = 0.05) but not significantly.ConclusionsOf the MALT lymphoma cases, 12 cases were diagnosed as having possible IgG4‐ROD. Our result have demonstrated that ocular IgG4‐ROD can predispose to the development of ocular adnexal MALT lymphoma. However, further longitudinal observations during the course of disease are needed to confirm whether B‐cell lymphoma originate from IgG4‐ROD.

A Gain-Of-Function Mutation in the Plcg2 Gene Protects Mice from Helicobacter felis-Induced Gastric MALT Lymphoma.

Gastric mucosa-associated lymphoid tissue (MALT) lymphomas develop from a chronic Helicobacter infection. Phospholipase C gamma 2 (PLCG2) is important for B-cell survival and proliferation. We used BALB/c mice with a gain-of-function mutation in the Plcg2 gene (Ali5) to analyze its role in the development of gastric MALT lymphoma. Heterozygous BALB/c Plcg2Ali5/+ and wildtype (WT) mice were infected with Helicobacter felis (H. felis) and observed up to 16 months for development of gastric MALT lymphomas. In contrast to our initial hypothesis, Plcg2Ali5/+ mice developed MALT lymphomas less frequently than their WT littermates after long-term infection of 16 months. Infected Plcg2Ali5/+ mice showed downregulation of proinflammatory cytokines and decreased H. felis-specific IgG1 and IgG2a antibody responses. These results suggested a blunted immune response of Plcg2Ali5/+ mice towards H. felis infection. Intriguingly, Plcg2Ali5/+ mice harboured higher numbers of CD73 expressing regulatory T cells (Tregs), possibly responsible for impaired immune response towards Helicobacter infection. We suggest that Plcg2Ali5/+ mice may be protected from developing gastric MALT lymphomas as a result of elevated Treg numbers, reduced response to H. felis and decrease of proinflammatory cytokines.

Synchronous Occurrence of Papillary Thyroid Carcinoma and Mucosa-Associated Lymphoid Tissue Lymphoma: a Single Case Report

Papillary thyroid carcinoma (PTC) is a common lesion, accounting for 70–80% of all thyroid cancers, whereas mucosa-associated lymphoid tissue (MALT) lymphoma of thyroid gland is rare. A simultaneous occurrence of both malignancies is extremely rare. 57 years old Korean woman diagnosed with Hashimoto' s thyroiditis at left lobe of thyroid gland where atypical cells of undetermined significance at right lobe. Later, left lobe was confirmed with malignant lymphoma during series of fine-needle aspiration biopsy. Right lobe was interpreted as malignant lesions, such as papillary thyroid carcinoma based on ultrasonography images and previous biopsy results. Total thyroidectomy was performed. Pathology reported papillary thyroid carcinoma at right lobe and MALT lymphoma at left lobe. There were no post-operative complications and no recurrence yet reported. Since an association between Hashimoto' s thyroiditis and development of MALT lymphoma has been reported previously, a history of Hashimoto thyroiditis should be suspected MALT lymphoma.

Management of Suspicious Mucosa-Associated Lymphoid Tissue Lymphoma in Gastric Biopsy Specimens Obtained during Screening Endoscopy

It is often difficult to differentiate gastric mucosa-associated lymphoid tissue (MALT) lymphoma from Helicobacter pylori-associated follicular gastritis, and thus, it becomes unclear how to manage these diseases. This study aimed to explore the management strategy for and the long-term outcomes of suspicious gastric MALT lymphoma detected by forceps biopsy during screening upper endoscopy. Between October 2003 and May 2013, consecutive subjects who were diagnosed with suspicious gastric MALT lymphomas by screening endoscopy in a health checkup program in Korea were retrospectively enrolled. Suspicious MALT lymphoma was defined as a Wotherspoon score of 3 or 4 upon pathological evaluation of the biopsy specimen. Of 105,164 subjects who underwent screening endoscopies, 49 patients with suspicious MALT lymphomas who underwent subsequent endoscopy were enrolled. Eight patients received a subsequent endoscopy without H. pylori eradication (subsequent endoscopy only group), and 41 patients received H. pylori eradication first followed by endoscopy (eradication first group). MALT lymphoma development was significantly lower in the eradication first group (2/41, 4.9%) than in the subsequent endoscopy only group (3/8, 37.5%, P = 0.026). Notably, among 35 patients with successful H. pylori eradication, there was only one MALT lymphoma patient (2.9%) in whom complete remission was achieved, and there was no recurrence during a median 45 months of endoscopic follow-up. H. pylori eradication with subsequent endoscopy would be a practical management option for suspicious MALT lymphoma detected in a forceps biopsy specimen obtained during screening upper endoscopy.