Mucosa-associated lymphoid tissue lymphoma with t(11;18)(q21;q21) translocation: long-term follow-up results

Gastric Mucosa-associated Lymphoid Tissue Lymphoma That Relapsed after 11 Years Subsequent to Achieving Complete Remission

A 38-year-old Japanese man was diagnosed with extranodal marginal zone lymphoma of the mucosa-associated lymphoid tissue in the stomach (gastric MALT lymphoma). Fluorescence in situ hybridization analysis revealed the absence of t (11;18) (q21;q21) translocation but the presence of extra copies of MALT1, indicating tetrasomy 18. Helicobacter pylori eradication led to complete remission (CR). However, the gastric MALT lymphoma relapsed after 11 years old. This case underscores the need for long-term observation (>10 years) of patients with gastric MALT lymphoma. Further investigation is warranted to elucidate the correlation between trisomy/tetrasomy 18 and the recurrence propensity.

B-cell non-Hodgkin lymphomas

B-cell lymphomas occur with an incidence of 20 new cases per 100 000 people per year in high-income countries. They can affect any organ and are characterised by heterogeneous clinical presentations and courses, varying from asymptomatic, to indolent, to very aggressive cases. Since the topic of B-cell non-Hodgkin lymphomas was last reviewed in The Lancet in 2017, a deeper understanding of the biological background of this heterogeneous group of malignancies, the availability of new diagnostic methods, and the development and implementation of new targeted and immunotherapeutic approaches have improved our ability to treat patients. This Seminar provides an overview of the pathobiology, classification, and prognostication of B-cell non-Hodgkin lymphomas and summarises the current knowledge and standard of care regarding biology and clinical management of the most common subtypes of mature B-cell non-Hodgkin lymphomas. It also highlights new findings in deciphering the molecular background of disease development and the implementation of new therapeutic approaches, particularly those targeting the immune system.

Usefulness and Limitations of Current Diagnostic Strategies for Pulmonary Mucosa-Associated Lymphoid Tissue Lymphoma: Lessons Learned From a Large Cohort

CONTEXT.—

The pathologic diagnosis of pulmonary extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) is challenging.

OBJECTIVE.—

To evaluate the diagnostic usefulness and limitations of current diagnostic strategies for pulmonary MALT lymphoma.

DESIGN.—

A retrospective review of 120 cases of pulmonary MALT lymphoma from 2014 through 2021 was performed.

RESULTS.—

Clinicoradiologic presentations overlapped with previous observations in patients with MALT lymphoma, such as a wide age range, female predominance, frequent association with autoimmune disease or immunodeficiency, and broad imaging findings. The histopathologic diagnosis was based on a combination of morphology, immunohistochemistry, and demonstration of B-cell lineage clonality. Two-thirds (76 of 113) of MALT lymphomas had lymphoplasmacytoid cytomorphology. Occasionally, MALT lymphomas were associated with granulomas/giant cells (29%, 35 of 120) or immunoglobulin deposition disease (21%, 25 of 120), including light chain/heavy chain deposition disease, amyloidosis, and/or crystal storing histiocytosis. While CD5, CD10, Bcl-2, and Bcl-6 rarely revealed aberrancies, aberrant CD43 expression either on B-cells or on plasma cells was detected in 42% (27 of 64) of cases, including cases for which proof of clonality could not be obtained. κ/λ in situ hybridization was particularly useful for tumors with lymphoplasmacytoid morphology but performed poorly in lymphomas having no plasmacytic differentiation. κ/λ immunohistochemistry showed no additional usefulness when applied together with κ/λ in situ hybridization. Immunoglobulin gene rearrangement studies by polymerase chain reaction achieved high detection rates of clonality in all cytomorphologic subgroups.

CONCLUSIONS.—

Our study offers a practical evaluation of common diagnostic tests in pulmonary MALT lymphoma. We offer recommendations for a diagnostic workup that takes into consideration the usefulness and the specific limitations of the various diagnostic strategies.

Waldenstrom's macroglobulinemia-like B cell lymphoma with MYD88 L265P mutation and t(14;18)(q32;q21) involving IGH-MALT1

A 65-year-old woman was referred to the hospital for further investigation of weight loss, hyperproteinemia, and anemia. Serum immunofixation electrophoresis revealed IgM-κ M protein. Bone marrow examination revealed an increase in the number of B -cells with immunoglobulin kappa light-chain restriction. Although the MYD88 L265P mutation was identified in bone marrow mononuclear cells, which suggested the diagnosis of Waldenstrom's macroglobulinemia (WM), a fusion signal of IgH-MALT1, which is commonly observed in extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) lymphoma, was also identified. Here, we describe a rare case of low-grade B-cell lymphoma with MYD88 L265P mutations accompanying IgH-MALT1.

Clinical Management of Patients with Gastric MALT Lymphoma: A Gastroenterologist's Point of View

Gastric mucosa-associated lymphoid tissue (MALT) lymphomas (GML) are non-Hodgkin lymphomas arising from the marginal zone of the lymphoid tissue of the stomach. They are usually induced by chronic infection with Helicobacter pylori (H. pylori); however, H. pylori-negative GML is of increasing incidence. The diagnosis of GML is based on histological examination of gastric biopsies, but the role of upper endoscopy is crucial since it is the first step in the diagnostic process and, with currently available novel endoscopic techniques, may even allow an in vivo diagnosis of GML per se. The treatment of GML, which is usually localized, always includes the eradication of H. pylori, which should be performed even in H. pylori-negative GML. In the case of GML persistence after eradication of the bacteria, low-dose radiotherapy may be proposed, while systemic treatments (immunochemotherapy) should be reserved for very rare disseminated cases. In GML patients, at diagnosis but even after complete remission, special attention must be paid to an increased risk of gastric adenocarcinoma, especially in the presence of associated gastric precancerous lesions (gastric atrophy and gastric intestinal metaplasia), which requires adequate endoscopic surveillance of these patients.

Effect of Helicobacter pylori eradication therapy on the response of MALT-Gastric lymphoma

INTRODUCTION

The link between gastric mucosa-associated lymphoid tissue lymphoma (LG-MALT) and chronic Helicobacter Pylori (HP) infection had led to a real revolution in the management of the disease.

AIMS

To study the results of the HP eradication therapy and to clarify its place in the tumor response.

METHODS

A descriptive retrospective bicentric study, between January 2007 and December 2016, including patients with LG-MALT treated in the gastroenterology departments of Sahloul hospital in Sousse and Habib Bougtafa hospital in Bizerte, and having received treatment for eradication of HP.

RESULTS

Sixty-three patients were included. The male/female sex ratio was 1.42. The average age was 58 years. The symptomatology was dominated by epigastric pain (96.8%). On digestive endoscopy, the most frequent location and appearance were gastric antrum (39.6%) and ulcerations (89%). The lymphoma was classified as stage IE and IIE1 in 81% and 19% of cases, respectively. The HP status was positive in all patients. The HP eradication rate was 82.5% after three anti-HP treatment courses. Complete remission of lymphoma was obtained in 81% of patients at 18 months. Non-response to HP eradication therapy was observed in 19% of patients. Non-responder patients had a longer diagnostic delay (p=0.02), more diffuse endoscopic involvement (p=0.001) and a more frequent appearance of large gastric folds (p=0.001).

CONCLUSION

The course of LG-MALT is determined by the treatment for the eradication of HP. Its success promotes remission of lymphoma.

Treatment of refractory MALT lymphoma by lenalidomide plus bendamustine: A case report

RATIONALE

Marginal zone B cell lymphoma of the mucosa-associated lymphoid tissue (MALT lymphoma) has an indolent natural course and disseminates slowly. However, there is currently no consensus regarding the optimal treatment strategy for relapsed/refractory MALT lymphomas. Lenalidomide-bendamustine may be an effective regimen for such cases.

PATIENT CONCERNS

A 48-year-old Chinese male patient with MALT lymphoma and API2/MALT received 2 courses of standard-dose rituximab, cyclophosphamide, vincristine, prednisone regimen chemotherapy combined with Helicobacter pylori eradication therapy. However, this disease was not effectively managed.

DIAGNOSIS

MALT lymphoma.

INTERVENTIONS

The patient received lenalidomide-bendamustine (lenalidomide 25 mg on days 1-21 and bendamustine 90 mg/m2 on days 1-2) for 6 courses.

OUTCOMES

Lenalidomide-bendamustine was a safe and effective chemotherapy. No serious adverse events occurred during the treatment period. Ultrasound gastroscopy revealed that the tumor gradually shrank and eventually disappeared to complete remission.

LESSONS

The lenalidomide-bendamustine scheme might be a potentially effective option for patients with refractory or relapsed MALT lymphoma.

Recent Advances in the Genetic of MALT Lymphomas

Simple Summary

Mucosa-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.

Abstract

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.

What you always wanted to know about gastric MALT-lymphoma: a focus on recent developments

The stomach is the most common site of origin for extranodal lymphomas, with extranodal marginal zone B-cell of the mucosa associated lymphoid tissue (MALT-lymphoma) being the predominant subtype. MALT-lymphoma develops in mucosa associated lymphoid structures acquired by infection or chronic antigenic stimuli and may therefore arise in almost any organ of the human body. In spite of histopathologic similarities between various organs upon first glance, recent findings suggest pronounced differences between different sites, with a variety of features specific to gastric MALT-lymphoma. The objective of this review is to sum up the current knowledge on pathogenesis, molecular pathology, clinical presentation and therapeutic approaches to gastric MALT-lymphoma with in-depth discussion of recent developments.

How can we assess and measure prognosis for MALT lymphoma? A review of current findings and strategies

INTRODUCTION

: MALT (mucosa associated lymphoid tissue) lymphoma is a distinct type of B-cell lymphoma characterized by extranodal manifestation and an indolent clinical course with 10-year survival rates up to 90%. However, transformation to aggressive lymphoma may occur and treatment is indicated in case of symptomatic or progressive disease.

AREAS COVERED

: This review covers clinical and biological features potentially related to prognosis and outcome of MALT lymphoma patients, as well as available prognostic tools and risk stratification systems with a focus on the MALT-IPI (international prognostic index) and the POD24 (progression of disease at 24 months) cohort. In addition, we address the role of watch-and-wait, the importance of defining the optimal time point for treatment initiation and the relevance of depth of remission, which appear to be some of the central questions for physicians involved in the care of MALT lymphoma patients. A computerized database search using PubMed® was performed to identify available publications on prognostic factors and risk stratification tools in MALT lymphoma.

EXPERT OPINION

: Despite the development of disease-specific risk stratification systems, there is no clear concept how to measure prognosis and tailor treatment. Careful observation of the individual clinical course is essential to assess the optimal time point of treatment initiation and avoid overtreatment, particularly in patients with disseminated disease. In addition, early detection of patients with histological transformation is necessary, as these patients face a poor prognosis.

Significance of abnormal 53BP1 expression as a novel molecular pathologic parameter of follicular-shaped B-cell lymphoid lesions in human digestive tract

The digestive tract is a common site of extranodal malignant lymphomas (MLs) and benign lymphoid lesions (BLs). TP53-binding protein 1 (53BP1) expression has been widely investigated in class switch recombination but rarely in human lymphoid tissues with respect to tumorigenesis. We previously reported that immunofluorescence (IF) analysis of 53BP1 nuclear foci (NF), reflecting DNA double strand breaks, is useful for estimating genomic instability in different tumor types. In this study, we evaluated the potential of IF-based analysis of 53BP1 expression in differentiating MLs from BLs. We examined 231 biopsied tissue samples of primary MLs and BLs in the digestive tract. The 53BP1 immunoreactivity pattern was determined by multicolor IF. Compared to BLs, MLs showed a high frequency of abnormal 53BP1 expression (p < 0.0001). Statistically, abnormal 53BP1 expression is an effective test for distinguishing follicular lymphomas from BLs (specificity 98.6%, sensitivity 86.8%) and for distinguishing small B-cell lymphomas from BLs (specificity 98.3%, sensitivity 77.6%). Furthermore, a high frequency of abnormal 53BP1 expression was associated with “high-risk” MALT lymphomas, which exhibited t(11;18)(q21;21) (p = 0.0145). Collectively, these results suggest that IF-based analysis of 53BP1 expression in biopsy samples is a promising technique for diagnosing MLs in the digestive system.

Advances and novel developments in mechanisms of allergic inflammation

In the past decade, research in the molecular and cellular underpinnings of basic and clinical immunology has significantly advanced our understanding of allergic disorders, allowing scientists and clinicians to diagnose and treat disorders such as asthma, allergic and nonallergic rhinitis, and food allergy. In this review, we discuss several significant recent developments in basic and clinical research as well as important future research directions in allergic inflammation. Certain key regulatory cytokines, genes and molecules have recently been shown to play key roles in allergic disorders. For example, interleukin-33 (IL-33) plays an important role in refractory disorders such as asthma, allergic rhinitis and food allergy, mainly by inducing T helper (Th) 2 immune responses and clinical trials with IL-33 inhibitors are underway in food allergy. We discuss interleukin 4 receptor pathways, which recently have been shown to play a critical role among the allergic inflammatory pathways that drive allergic disorders and pathogenesis. Further, the cytokine thymic stromal lymphopoietin (TSLP) has recently been shown as a factor in maintaining immune homeostasis and regulating type 2 inflammatory responses at mucosal barriers in allergic inflammation and targeting TSLP-mediated signalling is considered an attractive therapeutic strategy. In addition, new findings establish an important T cell-intrinsic role of mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1) proteolytic activity in the suppression of autoimmune responses. We have seen how mutations in the filaggrin gene are a significant risk factor for allergic diseases such as atopic dermatitis, asthma, allergic rhinitis, food allergy, contact allergy, and hand eczema. We are only beginning to understand the mechanisms by which the human microbiota may be regulating the immune system, and how sudden changes in the composition of the microbiota may have profound effects, linked with an increased risk of developing chronic inflammatory disorders, including allergies. New research has shown the important but complex role monocytes play in disorders such as food allergies. Finally, we discuss some of the new directions of research in this area, particularly the important use of biologicals in oral immunotherapy, advances in gene therapy, multifood therapy, novel diagnostics in diagnosing allergic disorders and the central role that omics play in creating molecular signatures and biomarkers of allergic disorders such as food allergy. Such exciting new developments and advances have significantly moved forth our ability to understand the mechanisms underlying allergic diseases for improved patient care.

Case report of API2-MALT1 fusion-positive MALT lymphoma arising from bilateral submandibular glands with no evidence of autoimmune syndromes

Mucosa-associated lymphoid tissue (MALT) lymphoma arising from the salivary glands is usually associated with chronic infection or autoimmune syndromes, such as primary Sjogren syndrome. The occurrence of t(11;18)/API2-MALT1 is rare in salivary MALT lymphoma. Here we describe a case of API2-MALT1 fusion-positive MALT lymphoma of the bilateral submandibular glands with no evidence of autoimmune syndromes. A 70-year-old man complained of a painless swelling in the bilateral submandibular gland. Serology examination results were negative for anti-SSA and anti-SSB. His right submandibular gland was dissected, and he was diagnosed with MALT lymphoma with the API2-MALT1 fusion gene. Positron emission tomography/computed tomography scanning indicated mild fluorine-18-fluorodeoxyglucose uptake in the left submandibular gland and liver. He was treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone. After 6 years, the patient is alive and disease free. In the present case, the patient with API2-MALT1 fusion-positive MALT lymphoma had a good outcome despite the advanced clinical stage.

Histologic transformation of t(11;18)-positive MALT lymphoma presented with aberrant T-cell marker expression

Mucosa-associated lymphoid tissue (MALT) lymphoma with t(11;18)(q21;q21), resulting in an API2-MALT1 fusion transcript, is reported to rarely transform into aggressive lymphoma. Here, we report the clinical course of a patient who experienced histologic transformation after 20 years' disease history of t(11;18)-positive MALT lymphoma. The patient suddenly developed a large intrapelvic mass and ascites with a rapid increase in lactate dehydrogenase. Cytology of the ascites detected large abnormal cells, and flow cytometric analysis revealed that the cells were positive for cytoplasmic CD3, CD4, and CD38, and partially positive for CD7, but negative for CD19 and CD20. Antigen receptor gene rearrangement analysis and in situ hybridization of the immunoglobulin light chains confirmed that the tumor cells were of B-cell lineage. Chromosomal analysis showed complex karyotypes with intraclonal variation, and in addition to t(11;18), t(8;14) and heterozygous loss of the TP53 were demonstrated. Although histological and phenotypic features were significantly altered from the original MALT lymphoma, the presence of t(11;18) led us to the diagnosis of histologic transformation of MALT lymphoma. Although transformation of t(11;18)-positive MALT lymphoma into aggressive lymphoma is extremely rare, it may occur, probably with additional genetic abnormalities such as cMYC rearrangement and/or the loss of TP53.