Les lymphomes gastriques du MALT

Helicobacter Pylori-Induced Gastric Infections: From Pathogenesis to Novel Therapeutic Approaches Using Silver Nanoparticles

Helicobacter pylori is the first formally recognized bacterial carcinogen and the most important single digestive pathogen responsible for the induction of gastroduodenal diseases such as gastritis, peptic ulcer, and, finally, gastric neoplasia. The recently reported high rates of antimicrobial drug resistance hamper the current therapies of H. pylori, with therapeutic failure reaching up to 40% of patients. In this context, new treatment options and strategies are urgently needed, but the successful development of these new therapeutic tools is conditioned by the understanding of the high adaptability of H. pylori to the gastric acidic environment and the complex pathogenic mechanism. Due to several advantages, including good antibacterial efficiency, possible targeted delivery, and long tissular persistence, silver nanoparticles (AgNPs) offer the opportunity of exploring new strategies to improve the H. pylori therapy. A new paradigm in the therapy of H. pylori gastric infections using AgNPs has the potential to overcome the current medical limitations imposed by the H. pylori drug resistance, which is reported for most of the current organic antibiotics employed in the classical therapies. This manuscript provides an extensive overview of the pathology of H. pylori-induced gastritis, gastric cancer, and extradigestive diseases and highlights the possible benefits and limitations of employing AgNPs in the therapeutic strategies against H. pylori infections.

The role of Helicobacter pylori eradication in the treatment of diffuse large B-cell and marginal zone lymphomas of the stomach

PURPOSE OF REVIEW

This review is focused on the effect of Helicobacter pylori eradication with antibiotics in patients with primary gastric lymphomas of indolent and aggressive nature.

RECENT FINDINGS

Gastrointestinal lymphoma is the most common form of extranodal lymphoma, involving primarily the stomach in 60-75% of cases. The most common histological subtypes are diffuse large B-cell lymphoma (DLBCL) and marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT)-type. H. pylori infection has been implicated in the pathogenesis of gastric MALT lymphoma; its role in gastric DLBCL remains controversial. Recently, international guidelines established that patients with gastric MALT lymphoma should be treated with upfront H. pylori-eradicating antibiotic therapy and that residual microscopic or molecular disease does not need for additional antiblastic treatment. The excellent prognosis of patients with gastric DLBCL managed with conservative chemo-radiotherapy led some investigators to test H. pylori eradication as exclusive treatment in prospective trials, keeping chemo-radiotherapy for unresponsive patients. This conservative strategy was well tolerated and active in patients with limited-stage DLBCL (±MALT areas) of the stomach.

SUMMARY

H. pylori eradication is a suitable strategy as exclusive upfront treatment for both patients with MALT-type lymphomas or with DLBCL of the stomach. Additional trials are needed to elucidate related controversial issues.

Marginal zone lymphomas and infectious agents

A link with infectious agents, bacteria and viruses in particular, has been reported for many lymphoma entities. Marginal zone lymphomas (extranodal, nodal and splenic forms) are frequently associated with chronic infections, with important clinical, molecular, biological, and therapeutic implications. The well-known correlation between Helicobacter pylori and gastric MALT-lymphoma, the recently reported links between Chlamydophila psittaci and ocular adnexal MALT-lymphoma and Borrelia burgdorferi and cutaneous MALT lymphoma constitute the best studied examples of lymphomagenic activity of bacteria, while the hepatitis C virus represents the most extensively investigated virus associated with marginal zone lymphomas. Biological and clinical features, therapeutic implications and future perspectives of these lymphoma-microbial associations are discussed in this review.

[Primary digestive tract lymphoma in central region of Tunisia: anatomoclinical study and therapeutic results about 153 cases]

Primary gastro-intestinal lymphoma (PGIL) is the most common type of extra-nodal non Hodgkin's lymphoma. Their clinical and histological presentations are heterogeneous depending on the site of the lesion. There is no consensus regarding the role of surgery and chemotherapy in the therapeutic approach. In our country epidemiology of the disease is unknown with IPSID being the most frequent type. We report anatomo-clinical features and prognostic factors of PGIL and compare intestinal to gastric forms in our region. This is a retrospective study of 153 cases of PGIL in adults diagnosed and treated in the department of medical oncology in Farhat Hached Hospital between 1994 and 2006. The median age was 52 years and the sex-ratio 2.1. Tumor sites were gastric (67%), intestinal (26%) and gastrointestinal (7%). Abdominal pain (87%) followed by vomiting and diarrhoea (37 and 15%) were the most common symptoms. Performance status (PS) < 2 was seen in 80% of patients, high grade lymphoma in 70.5% of cases and B phenotype was noted in 85%. MALT lymphoma accounts for 50% of cases, and IPSID for only 5% of PGIL. About 47.5% of cases were stage IE, 138 patients had chemotherapy with an objective response rate of 77%. Only 46% of patients had surgery (14 for surgical complication, 6 for residual tumor after chemotherapy and 22 to have histological diagnosis). The five-year overall survival (OS) was 62%. In high grade lymphoma patients favorable prognostic factors for OS included young age < or = 60 years, PS < 2, normal serum LDH, hemoglobin > 12 g/dL, B phenotype, localised stage (IE-IIE1), anthracycline-based chemotherapy regimen, achieving complete or partial response to induction chemotherapy and no relapse. In multivariate study only relapse and PS were significant prognostic factors for OS. In low-grade lymphoma patients, none of these factors had a significant correlation with OS: age < or = 60 years, PS < 2, stage (IE-IIE1), response to induction chemotherapy, relapse. Compared to gastric lymphomas, intestinal cases occurred at a younger age, frequently with diarrhoea, weight loss, and occlusion. They are more often high-grade, T phenotype and have locally advanced stage (IIE); surgery is more common in this group. We conclude that stomach is the main site of PGIL in our region, intestinal lymphoma is less frequent and IPSID has become rare. Recent progress in chemotherapy has allowed good therapeutic results with a conservative approach. Surgery may be performed in case of emergency or for residual lesions after medical treatment.

Gastric MALT Lymphoma Presenting as Waldenström's Macroglobulinemia Without Bone Marrow Involvement

We report a case of gastric mucosa-associated lymphoid tissue (MALT) lymphoma with macroglobulinemia in a 59-year-old man who presented with melena. A computed tomography scan of the abdomen showed irregular thickening of the wall of the stomach, and endoscopic examination disclosed enlarged and inflammatory folds of the fundus. Histopathologic examination of gastric samples showed mucosal infiltration by small lymphocytes, which were positive for CD20 and negative for CD10 and CD23, confirming the diagnosis of gastric MALT lymphoma. Serum electrophoresis detected a monoclonal peak and immunoelectrophoresis revealed an immunoglobulin M kappa component. Bone marrow aspirate and biopsy results were normal. The patient received chemotherapy. After treatment, he was in complete remission, and the serum monoclonal component had disappeared. Our observation is uncommon because of important macroglobulinemia occurring in gastric MALT lymphoma without bone marrow involvement.

Intraoperative Finding of a Gastric Lymphoma during Gastric Bypass Surgery

A case is reported of intraoperative diagnosis and treatment of a low-grade gastric MALT lymphoma during gastric bypass surgery for morbid obesity. Laparoscopic resectional gastric bypass was followed by adjuvant chemotherapy.