Acquired gastric mucosa-associated lymphoid tissue (MALT): a review with special emphasis on association with extragastric diseases and management problems of gastric MALT

A novel prognostic nomogram for patients with extragastric mucosa-associated lymphoid tissue lymphoma: A multicenter study

Background

The aim of this study was to explore predictors and construct a nomogram for risk stratification in primary extragastric mucosa‐associated lymphoid tissue (MALT) lymphoma.

Methods

Extragastric MALT lymphoma cases newly diagnosed between November 2010 and April 2020 were assessed to construct a progression‐free survival (PFS)‐related nomogram. We also performed external validation of the nomogram in an independent cohort.

Results

We performed multivariate analyses of 174 patients from 3 hospitals who were included in the training cohort. Stage, hepatitis B virus surface antigen (HBsAg) status, and Ki67 expression were significantly associated with PFS. These three factors were used to construct a nomogram, which was shown to have a C‐index of 0.89. Two risk groups (low risk and high risk) were identified by the prognostic model. The 5‐year PFS was 98.9% for the low‐risk group and 69.3% for the high‐risk group (p < 0.001). The overall survival (OS) could also be effectively distinguished by the nomogram, resulting in an OS of 100% for the low‐risk group and 94.6% for the high‐risk group (p = 0.01). These results were validated and confirmed in an independent cohort with 165 patients from another three hospitals. The 5‐year PFS rates were 94.8% and 66.7% for the low‐risk and high‐risk groups, respectively (p < 0.001). The 5‐year OS rates were 97.9% and 88.4%, respectively (p = 0.016).

Conclusion

The nomogram could well distinguish the prognosis of low‐ and high‐risk patients with extragastric MALT lymphoma and is thus recommended for clinical use.

Synchronous gastric and colonic MALT-lymphoma in coeliac disease: a long-term follow-up on gluten-free diet

We describe the first case of synchronous gastric and colonic mucosa-associated lymphoid tissue lymphoma in coeliac disease. After refusing any other treatment, the patient started a gluten-free diet but a re-evaluation 3 years later failed to demonstrate improvement of the gastric neoplasia on a gluten-free diet, whilst the colonic mucosa-associated lymphoid tissue lymphoma behaviour was unknown (the patient refused a new colonoscopic evaluation).

Rapidly progressive diffuse large B-cell lymphoma with initial clinical presentation mimicking seronegative Wegener's granulomatosis

Here we present a 40-yr-old male patient with an aggressive B-cell lymphoma, who presented 2 yr earlier with polyarthritis, and was responsive to steroids and oral methotrexate. Thereafter he developed skin and lung lesions which on biopsy consisted of mixed 'inflammatory' infiltrates with granulomatous vasculitis. A diagnosis of seronegative Wegener's granulomatosis was made and the patient received a combination of prednisone and cyclophosphamide with clinical improvement and clearance of the radiological lesions in the lungs. The patient was now completely asymptomatic for 1 yr, but then generalized lymphadenopathy appeared, which was shown by histopathology to be large B-cell lymphoma, also involving the bone marrow. Despite intensive chemotherapy, his disease could not be controlled because of primary chemoresistance, which was perhaps in some way related to exposure to the suboptimal doses of chemotherapy given during the 'inflammatory' period before the diagnosis of lymphoma was established. This case illustrates the occasional difficulty in distinguishing between extranodal lymphoproliferative diseases and autoimmune disorders especially when clonality cannot be proved. It also shows the possible risk of 'masking' a true lymphoma by treating non-malignant diseases with immunosuppressive agents, which may eventually contribute to the development of chemoresistant lymphoma.

Disappearance of gastric mucosa-associated lymphoid tissue in hepatitis C virus-positive patients after anti-hepatitis C virus therapy

OBJECTIVE

Mucosa-associated lymphoid tissue, which has a follicular structure closely resembling Peyer patches, is absent in the normal gastric mucosa, but it can develop in several chronic conditions. Since we recently detected hepatitis C virus-RNA in gastric mucosa-associated lymphoid tissue of patients with chronic hepatitis C, we tried to treat hepatitis C virus infection to evaluate the effect of antiviral therapy on gastric mucosa-associated lymphoid tissue.

METHODS

Eighteen patients (12 men and 6 women; mean age: 52 years, range: 33-71 years) affected by chronic hepatitis C virus and with gastric mucosa-associated lymphoid tissue were enrolled. We enrolled only patients hepatitis C virus-positive, mucosa-associated lymphoid tissue-positive, and Helicobacter pylori-negative (8 patients) or hepatitis C virus-positive patients in whom anti-H. pylori therapy did not obtain disappearance of gastric mucosa-associated lymphoid tissue (10 patients). Hepatitis C virus was evaluated by hepatic biopsy with histologic evaluation and serologic examination; Gastric mucosa-associated lymphoid tissue was scored using Wotherspoon score. All patients were treated with recombinant leukocyte interferon-alpha-2b plus oral ribavirin for 6 months. The hepatitis C virus RNA was assayed at entry and at 3 months after stopping treatment. Virologic response was defined as undetectable levels of serum hepatitis C virus RNA 3 months after stopping treatment; esophagogastroduodenoscopy was repeated at this time to evaluate the effect of anti-hepatitis C virus therapy on acquired gastric mucosa-associated lymphoid tissue.

RESULTS

Two (11.11%) patients were withdrawn from the study. Hepatitis C virus cure was obtained in 11/16 patients (68.75%), and in all of them we obtained disappearance of gastric mucosa-associated lymphoid tissue (P < 0.01). Hepatitis C virus infection persisted, but with very lower levels, in 5 of 16 patients (31.25%): in 3 patients gastric mucosa-associated lymphoid tissue persisted (but in 2 it decreased from grade 3 to grade 2), while in 2 it disappeared.

CONCLUSIONS

We showed clearly that there is a strict correlation between hepatitis C virus infection and acquired MALT, obtaining the disappearance of this acquired immunologic acquired gastric tissue curing hepatitis C virus infection. However, further studies are needed to clarify there is the same correlation between hepatitis C virus infection and gastric mucosa-associated lymphoid tissue lymphomas in hepatitis C virus-positive patients.

Prevalence and pattern of antinuclear autoantibodies in 347 patients with non-Hodgkin's lymphoma

The presence of antinuclear autoantibodies (ANA) was investigated in a large cohort of patients with non-Hodgkin's lymphoma (NHL) in order to assess their frequency, specificity and prognostic relevance. ANA were analysed in 347 patients with different histological subgroups of NHL and in 213 controls using an indirect immunofluorescence technique on HEp2 cells. As the appearance of autoantibodies may be found after treatment of NHL, samples were collected at the time of diagnosis of NHL before any therapy. Sixty-six (19%) NHL patients and 12 (5.6%) patients from the control group displayed ANA. The prevalence between the two groups was found to be significantly higher in NHL patients (P < 0.0001) with a marked increased prevalence in follicular and mantle cell lymphoma subgroups. Autoantibodies directed against mitotic proteins or mitotic-associated proteins were found in 6.9% of NHL patients versus 0.5% in the control group (P < 0.001), with a significantly increased incidence in follicular and mantle cell lymphoma subgroups (P < 0.0001). Some 28% of the patients with positive ANA displayed clinical symptoms that could correspond to classical autoimmune manifestations, this frequency appearing to be higher in the marginal zone/mucosa-associated lymphoid tissue lymphoma subgroup. These data demonstrate a significant incidence of ANA before any treatment in NHL occurrence, which seems to be higher in some histological subgroups with particular ANA, such as ANA directed against mitotic proteins or mitotic-associated proteins.

Low-grade B-cell bronchial associated lymphoid tissue (BALT) lymphoma

Low-grade B-cell bronchial associated lymphoid tissue (BALT) lymphoma is a distinct subgroup of non-Hodgkin's lymphoma. Chronic antigen stimulation, triggered by autoimmune process or persistent infection may precede the development of BALT lymphoma. The lymphoma cells originate from the marginal zone and by invading the bronchial epithelial tissue, give rise to the lymphoepithelial lesion. BALT lymphoma shares the morphologic, immunophenotypic, and cytogenetic characteristics of other mucosa associated lymphoid tissue lymphomas. A majority of the patients are asymptomatic and pulmonary lesions are incidentally discovered on a routine chest radiograph. However, the clinical and radiographic features of BALT lymphoma are nonspecific. The disease is often localized at the time of diagnosis and responds favorably to local treatment, but the optimal management is not clearly defined. Overall, BALT lymphoma has a favorable prognosis and is associated with long-term survival.

Detection of HCV RNA in gastric mucosa-associated lymphoid tissue by in situ hybridization: evidence of a new extrahepatic localization of HCV with increased risk of gastric malt lymphoma

OBJECTIVES

Mucosa-associated lymphoid tissue (MALT) is absent in the normal gastric mucosa but it can develop in several conditions, such as Helicobacter pylori infection. A certain correlation between hepatitis C virus (HCV) infection and low grade MALT lymphomas has recently been reported. The aim of this study was to investigate the presence of HCV RNA in acquired gastric MALT of HCV-infected patients using the in situ hybridization technique.

METHODS

Twenty-five patients (16 male and nine female, average age = 56.6 yr [range = 33-75]) affected by chronic HCV hepatitis and with gastric MALT were studied. Giemsa stain and the rapid urease test were also used to evaluate the presence of H. pylori. A polymerase chain reaction product corresponding to the complete 5' noncoding region of the HCV genome was cloned directly in the pCR 1000 vector on gastric biopsies with acquired MALT.

RESULTS

Twenty patients showed grade 2 gastric MALT and five showed grade 3, and H. pylori's presence was detected in 18 of 25 patients (72%). Using in situ hybridization, we detected HCV RNA in gastric acquired MALT of seven of 25 patients (28%): five showed grade 2 gastric MALT (two of these were H. pylori negative and the other three were positive), whereas two patients showed grade 3 gastric MALT (without H. pylori infection).

CONCLUSIONS

This study shows that HCV not only may colonize gastric MALT but also may permit the development of a grade of acquired MALT, which may represent the first step toward a MALT lymphoma. However, further studies are needed to demonstrate the antigenic role of HCV in the progression of acquired MALT into MALT lymphoma.

Helicobacter pylori-associated gastric MALT lymphoma in liver transplant recipients

BACKGROUND

Immunosuppressed transplant recipients are at increased risk of developing several forms of malignancy. The aim of this study is to report the clinical presentation, treatment, and outcome of four liver transplant recipients with Helicobacter pylori-associated gastric mucosae-associated lymphoid tissue (MALT) lymphoma.

METHODS

The medical records of four liver transplant recipients with gastric MALT lymphoma were reviewed. In situ hybridization for Epstein-Barr-encoded ribonucleic acid was performed on formalin-fixed tissues.

RESULTS

All four subjects presented with abdominal symptoms at a mean of 6.1 years posttransplant. Ulcerative lesions biopsied at endoscopy demonstrated early-stage gastric MALT lymphoma with associated Helicobacter pylori gastritis. In situ hybridization revealed no evidence of Epstein-Barr virus infection in examined tissues. Antibiotic eradication of Helicobacter pylori lead to disease remission in three subjects with a mean follow-up of 21 months, and one subject failed to respond to antibiotics and radiation therapy and died from metastatic gastric adenocarcinoma.

CONCLUSIONS

Early-stage, low-grade gastric MALT lymphoma that was associated with Helicobacter pylori gastritis responded to antibiotic therapy with a sustained clinical remission in three of four treated subjects. If other studies confirm a higher than expected incidence of gastric MALT lymphoma in immunosuppressed transplant recipients with Helicobacter pylori infection, screening and treating Helicobacter pylori infection in selected transplant patients may prove beneficial.

[Physiopathology of Helicobacter pylori infections]

Helicobacter pylori (H.p.) causes active chronic gastritis in nearly all infected patients. Cytotoxic factors elaborated by H.p. as well as autoimmune cell damage from the abundant inflammatory response contribute to gastric epithelial cell injury. Antrum gastritis increases gastrin release. The impact of H.p.-infection on gastric acid physiology is complex and usually results in increased gastric acid secretion in duodenal ulcer patients and diminished acid output in patients with gastric cancer. Multiple clinical outcomes including asymptomatic gastritis, duodenal ulcer, gastric ulcer, gastric carcinoma and gastric MALT lymphoma are associated with H.p.-infection. Differences in disease manifestation seem to result from a complex interaction of bacterial virulence, host factors as well as environmental factors. The acid-secretory ability of the infected individual seems to be the main variable determining outcome: Patients with high acid production typically develop antrum-predominant gastritis and are at an increased risk for duodenal ulcer. In contrast patients with low gastric acid secretion frequently develop pangastritis, which may progress to chronic atrophic gastritis and carcinoma.