Magnifying NBI endoscopy clearly revealed detailed micromorphological differences corresponding to the histology and endoscopic findings among patients with different H. pylori-associated diseases.

Mucosa-associated lymphoid tissue (MALT) lymphomas are localized primarily in the gastrointestinal tract and are characterized by an indolent nature and favorable outcome with specifi c therapy. Gastric MALT lymphomas are closely linked to Helicobacter pylori (H. pylori) infection, for which eradication therapy is recognized as an effective primary treatment for the disease. However, there is little information about long-term outcomes after the therapy. In the present study, we elucidated the long-term outcomes of 74 patients (70 H. pylori-positive and 4 negative cases) followed up by endoscopy at least 12 months after exclusive eradication therapy alone. The median follow-up period was 46 months. When the remission status was estimated at the time point of 12 months post-eradication, the numbers of patients with complete remission (CR), histologically residual disease with macroscopic normalization (hRD), partial remission with more than 50% tumor reduction (PR) or no response (NR) were 56, 12, 2 and 4, respectively. During follow-ups of over 12 months post-eradication, 11 of the 12 hRD cases were belatedly induced to CR but one CR case histologically relapsed into hRD. One of the 2 PR cases eventually turned into hRD 20 months later. Therefore, 66 CR, 3 hRD, 1 PR, and 4 NR cases (including 3 H. pylorinegative) were identifi ed at the last follow-up of the present study. All 74 patients were followed up without any second-line therapies, but none exhibited disease progression. Thus, the long-term outcome of localized gastric MALT lymphoma after H. pylori eradication therapy was favorable. A watch and wait strategy may be a reasonable approach for hRD since the majority might be in the process of turning into delayed CR. gatric MALT lymphoma; H. pylori eradication; long-term outcome; complete remission; radiotherapy.Tohoku

Mucosa-associated lymphoid tissue (MALT) lymphomas are extra-nodal B-cell lymphomas arising from MALT, and the most commonly affected organ is the stomach. Helicobacter pylori (H. pylori) eradication therapy with proton-pump inhibitors and antibiotics is the first-line therapy for H. pylori-positive gastric MALT lymphomas, but the effectiveness of the therapy for H. pylori-negative gastric MALT lymphomas remains controversial. Hence, we aimed to evaluate the effectiveness of this eradication therapy for H. pylorinegative MALT lymphomas. The H. pylori infection status of 158 gastric MALT lymphoma patients followed in our unit was judged by urea breath test, rapid urease test, histology of the biopsy specimen taken from the stomach during endocopy, and serum antibody against H. pylori. Seventeen patients that were negative for all four tests and did not have gastric mucosal atrophy were treated with antibiotic eradication therapy. The average age at diagnosis was 56.8 years old (range: 36-73 years), and the median follow-up period after H. pylori eradication in all 17 patients was 5.3 years (range: 0.3-12.7 years). Five patients (29.4%) achieved complete remission (CR) by eradication therapy alone. Comparison between the responding and non-responding patients revealed that the patients endoscopically diagnosed to have a single lesion of gastric MALT lymphoma were seen only in the responding group, whereas all non-responding patients had multiple lesions (P < 0.05). In conclusion, H. pylori eradication therapy achieved a favorable CR rate in H. pylori-negative gastric MALT lymphoma patients and could be considered as a first-line therapy, especially for patients with a single lesion.

Helicobacter pylori infection is the major cause for mucosa-associated lymphoid tissue (MALT) lymphoma and gastric cancers. On the other hand, gastric cancers are known to arise from gastric mucosal atrophy. We here report a case of signet ring cell gastric cancer that developed after radiation therapy for MALT lymphoma in H. pylori-uninfected patient whose stomach did not show gastric mucosal atrophy. A 58-year-old female was referred to our hospital for treatment of gastric MALT lymphoma. This patient was not infected with H. pylori, and upper gastrointestinal endoscopy revealed that she did not have gastric mucosal atrophy but had submucosal tumor-like MALT lymphoma lesion in the anterior wall of the upper gastric body. Since conventional eradication therapy was ineffective, her whole stomach was irradiated as a second-line therapy. The MALT lymphoma lesion turned into complete remission state after the therapy. The patient was followed every 6 months by upper gastrointestinal endoscopy for 4 years as complete remission until a newly developed decolorized depressed lesion was detected in the greater curvature of the proximal antrum, a completely different location from the MALT lymphoma lesion. A biopsy specimen from the lesion contained signet ring cell carcinoma, and she was successfully treated by endoscopic submucosal dissection. No signs of recurrence have been detected so far. The radiation therapy for MALT lymphoma might be associated with the occurrence of this signet ring cell gastric cancer, and since MALT lymphoma is indolent in nature, this case suggests that careful consideration is required when choosing the second-line therapy for MALT lymphoma patients.

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The microsurface structure of the gastric mucosa surrounding gastric cancer lesions differed between patients with differentiated and undifferentiated gastric cancer. These findings are expected to be useful for the early detection of gastric carcinoma lesions or for the determination of extensions of carcinoma lesions.