Gastric low-grade mucosal-associated lymphoid tissue-lymphoma: Helicobacter pylori and beyond

Clinical and endoscopic features of primary small bowel lymphoma: a single-center experience from mainland China

Objective

The worldwide incidence of primary small intestinal lymphoma (PSIL) is increasing. However, little is known about the clinical and endoscopic characteristics of this disease. The aim of this study was to investigate the clinical and endoscopic data of patients with PSIL, with the goal of enhancing our understanding of the disease, improving diagnostic accuracy, and facilitating more accurate prognosis estimation.

Methods

Ninety-four patients diagnosed with PSIL were retrospectively studied at Qilu Hospital of Shandong University between 2012 and 2021. The clinical data, enteroscopy findings, treatment modalities, and survival times were collected and analyzed.

Results

Ninety-four patients (52 males) with PSIL were included in this study. The median age of onset was 58.5 years (range: 19-80 years). Diffuse large B-cell lymphoma (n=37) was the most common pathological type. Abdominal pain (n=59) was the most frequent clinical presentation. The ileocecal region (n=32) was the most commonly affected site, and 11.7% of patients had multiple lesions. At the time of diagnosis, the majority of patients (n=68) were in stages I-II. A new endoscopic classification of PSIL was developed, including hypertrophic type, exophytic type, follicular/polypoid type, ulcerative type, and diffusion type. Surgery did not show a significant increase in overall survival; chemotherapy was the most commonly administered treatment. T-cell lymphoma, stages III-IV, "B" symptoms, and ulcerative type were associated with poor prognosis.

Conclusion

This study provides a comprehensive analysis of the clinical and endoscopic features of PSIL in 94 patients. This highlights the importance of considering clinical and endoscopic characteristics for accurate diagnosis and prognosis estimation during small bowel enteroscopy. Early detection and treatment of PSIL is associated with a favorable prognosis. Our findings also suggest that certain risk factors, such as pathological type, "B" symptoms, and endoscopic type, may affect the survival of PSIL patients. These results underscore the need for careful consideration of these factors in the diagnosis and treatment of PSIL.

The Debate between the Human Microbiota and Immune System in Treating Aerodigestive and Digestive Tract Cancers: A Review

The human microbiota comprises a group of microorganisms co-existing in the human body. Unbalanced microbiota homeostasis may impact metabolic and immune system regulation, shrinking the edge between health and disease. Recently, the microbiota has been considered a prominent extrinsic/intrinsic element of cancer development and a promising milestone in the modulation of conventional cancer treatments. Particularly, the oral cavity represents a yin-and-yang target site for microorganisms that can promote human health or contribute to oral cancer development, such as Fusobacterium nucleatum. Moreover, Helicobacter pylori has also been implicated in esophageal and stomach cancers, and decreased butyrate-producing bacteria, such as Lachnospiraceae spp. and Ruminococcaceae, have demonstrated a protective role in the development of colorectal cancer. Interestingly, prebiotics, e.g., polyphenols, probiotics (Faecalibacterium, Bifidobacterium, Lactobacillus, and Burkholderia), postbiotics (inosine, butyrate, and propionate), and innovative nanomedicines can modulate antitumor immunity, circumventing resistance to conventional treatments and could complement existing therapies. Therefore, this manuscript delivers a holistic perspective on the interaction between human microbiota and cancer development and treatment, particularly in aerodigestive and digestive cancers, focusing on applying prebiotics, probiotics, and nanomedicines to overcome some challenges in treating cancer.

Development and evaluation of a double-check support system using artificial intelligence in endoscopic screening for gastric cancer

BACKGROUND

This study aimed to prevent missing gastric cancer and point out low-quality images by developing a double-check support system (DCSS) for esophagogastroduodenoscopy (EGD) still images using artificial intelligence.

METHODS

We extracted 12,977 still EGD images from 855 cases with cancer [821 with early gastric carcinoma (EGC) and 34 malignant lymphoma (ML)] and developed a lesion detection system using 10,994 images. The remaining images were used as a test dataset. Additional validation was performed using a new dataset containing 50 EGC and 1,200 non-GC images by comparing the interpretation of ten endoscopists (five trainees and five experts). Furthermore, we developed another system to detect low-quality images, which are not suitable for diagnosis, using 2198 images.

RESULTS

In the validation of 1983 images from the 124 cancer cases, the DCSS diagnosed cancer with a sensitivity of 89.2%, positive predictive value (PPV) of 93.3%, and an accuracy of 83.3%. EGC was detected in 93.2% and ML in 92.5% of cases. Comparing with the endoscopists, sensitivity was significantly higher in the DCSS, and the average diagnostic time was significantly shorter using the DCSS than that by the trainees. The sensitivity, specificity, PPV, and accuracy in detecting low-quality images were 65.8%, 93.1%, 79.6%, and 85.2% for "Blur" and 57.8%, 91.7%, 82.2%, and 78.1% for "Mucus adhesion," respectively.

CONCLUSIONS

The DCSS showed excellent capability in detecting lesions and pointing out low-quality images.

Establishing an endoscopic diagnostic process system (M-system) for gastric MALT lymphoma of superficial-spreading type

OBJECTIVE

Gastric mucosa-associated lymphoid tissue lymphoma is a rare disease, which is associated with a low endoscopic diagnostic accuracy even on tissue biopsy. We aimed to establish a diagnostic process system (M-system) using detailed magnifying endoscopy images to improve the diagnostic efficiency of this disease.

METHODS

First, 34 cases from 16 patients with the diagnosis of mucosa-associated lymphoid tissue lymphoma were collected as the study group. The control group included randomly selected patients who were diagnosed with early differentiated carcinoma, undifferentiated carcinoma or inflammation. Then, the endoscopic images of these patients were analyzed by senior physicians. Finally, the M-system was established based on the data extracted from the images reviewed, and its diagnostic efficiency for mucosa-associated lymphoid tissue lymphoma was validated by the junior physicians.

RESULTS

A series of elements with high sensitivity and specificity for the diagnosis of mucosa-associated lymphoid tissue lymphoma on endoscopic images were extracted for the establishment of the M-system. Using the M-system, the diagnostic accuracy, sensitivity, specificity and correct indices of mucosa-associated lymphoid tissue lymphoma rose from 65.4 to 79.4%, 41.2 to 76.5%, 73.5 to 80.4% and 0.147 to 0.569%, respectively, all of which were statistically significant.

CONCLUSIONS

The M-system can improve the diagnostic accuracy of mucosa-associated lymphoid tissue lymphoma of the superficial-spreading type on detailed magnifying endoscopy. This would help in the early diagnosis of the disease and treatment, which would translate into improved clinical outcomes.

Pre-malignant signs of gastric MALT lymphoma

Mucosa-associated lymphoid tissue (MALT) lymphoma is the most common type of extra-nodal non-Hodgkin lymphoma, which mostly involves the stomach. The clinical suspicion and diagnosis are often challenging because of the lack of specific symptoms and conventional endoscopic findings. Three magnifying endoscopic signs of the gastric mucosa have been described as highly specific to the diagnosis of MALT lymphoma, such as (i) tree-like appearance of the microvessels; (ii) non-structural area; and (iii) ballooning crypt pattern. We report the case of a middle-aged woman in which these signs appeared chronologically over a period of 2 years, showing the association of the sequence of the endoscopic findings and the final histological diagnosis of gastric MALT lymphoma.

Gastrointestinal lymphoma: the new mimic

Background

Gastrointestinal (GI) lymphomas comprise a group of distinct clinicopathological entities of B- or T- cell type, with primary gastrointestinal Hodgkin lymphoma being extremely uncommon. The GI tract is the predominant site of extranodal non-Hodgkin lymphoma accounting for 30–40% of all extranodal lymphomas. In the Western world, the stomach is the most commonly involved site followed by the small bowel. Several chronic inflammatory and immune-mediated disorders which predispose to accelerated cell turnover may lead to the malignant transformation of gut lymphocytes and ultimately manifest as GI lymphoma. The challenge for the clinical gastroenterologist is that these tumors may have varied presentations, ranging from nonspecific symptoms such as dyspepsia or bloating to abdominal pain, nausea, vomiting, GI bleeding, diarrhea, weight loss or bowel obstruction.

Objective

We illustrate the range of presentations of GI lymphoma with examples based on consecutive cases evaluated at our institution over a 6-month period. These cases demonstrate how appropriately directed endoscopic evaluation with biopsies has the potential to provide a definitive diagnosis and allow the patient to proceed to definitive therapy.

Conclusions

The GI tract is the most commonly involved site for extranodal lymphoma with the stomach being most frequently involved organ. Chronic Helicobacter pylori infection, celiac disease, inflammatory bowel disease and autoimmune disorders may predispose to GI lymphoma. This heterogenous group of diseases has varied presentations that may mimic several other GI clinico-pathologic entities. GI lymphomas may be diagnosed with appropriately directed endoscopic evaluation coupled with generous tissue sampling and expert pathologic assessment. Management may range from antibiotic therapy, in the case of Helicobacter pylori-associated gastric MALT lymphoma, to chemotherapy with or without radiation and, in rare instances, surgery. There are presently no guidelines to direct endoscopic surveillance of GI lymphomas following treatment.

Two cases of gastric mucosa-associated lymphoid tissue (MALT) lymphoma masquerading as follicular gastritis

In this report, we describe two cases of extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) of the stomach, which presented with multiple small, whitish nodules in the gastric body. The endoscopic appearance was similar to that of lymphoid follicular hyperplasia found in follicular gastritis or nodular gastritis. Both patients were positive for Helicobacter pylori, and the eradication treatment resulted in complete remission of the lymphoma. However, recurrence was noted in one patient. These cases indicate that, although infrequent, gastric MALT lymphoma can show a nodular appearance resembling that of follicular gastritis.

MALT lymphoma: epidemiology, clinical diagnosis and treatment

Primary gastric lymphoma (PGL) represents a rare pathology, which can be easily misdiagnosed because of unspecific symptoms of the digestive tract. Histologically, PGL can vary from indolent marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) to aggressive diffuse large B-cell lymphoma (DLBCL). During the years, clinical trials revealed the important role of Helicobacter pylori (H. pylori) in the pathogenesis of gastric MALT lymphoma. Infection with Helicobacter pylori is an influential promoter of gastric lymphomagenesis initiation. Long-term studies revealed that eradication therapy could regress gastric lymphomas.

A Comparison of Five Different Treatment Regimens as the First-Line Treatment of Helicobacter pylori in Turkey

BACKGROUND

The H. pylori eradication success is low in countries with high antibiotic resistance to H. pylori.

OBJECTIVE

We retrospectively assessed the eradication rates achieved by five different regimens and aimed to compare the efficiency of bismuth enhanced sequential therapy and other treatments in a gastroenterology outpatient clinic a university-affiliated hospital.

DESIGN

Our study was carried out with a retrospective cohort design.

SETTING

This study assessed the gastroscopy examinations of patients.

PATIENTS

A total of 621 patients were included in the study. There were 122 patients in the quadruple treatment group, 168 patients in the classical sequential treatment group, 130 patients in the bismuth enhanced sequential therapy, 113 patients in the sequential treatment with levofloxacin, and 88 patients in the hybrid treatment.

MEASUREMENTS

Eradication rates of different regimens was analyzed by performing Chi-square and Tukey's honest significant difference test.

RESULTS

Eradication rates by ITT and PP analysis achieved by treatment groups were 74.6 and 75.6% in the quadruple treatment; 70.2 and 70.4% in the sequential treatment with clarithromycin, 88.5 and 90.3% in the bismuth enhanced sequential therapy, 77.9 and 78.5% in the sequential treatment with levofloxacin, and 76.1 and 76.2% in the hybrid treatment.

LIMITATIONS

The main limitation of our study was its retrospective nature. Different proton pump inhibitors were used in the treatment arms.

CONCLUSIONS

Bismuth-enhanced sequential therapy can be recommended to overcome resistance.

Synchronous Upper and Lower Gastrointestinal Mucosa-Associated Lymphoid Tissue Lymphomas

Mucosa-associated lymphoid tissue lymphoma (MALToma) is a subtype of B-cell non-Hodgkin's lymphoma, comprising ∼17% of all gastrointestinal (GI) tract lymphomas. It is associated with chronic inflammation and autoimmunity, for example Helicobacter pylori gastritis and Sjogren's syndrome, respectively. Approximately 50% of GI MALTomas occur in the stomach, with small bowel and colonic lesions being less frequent. Synchronous upper and lower GI MALTomas occur rarely, with few cases reported. We present the case of a 73-year-old patient who presented with change in bowel habit and was found to have synchronous multifocal upper and lower GI MALTomas, which did not respond to H. pylori cure or to rituximab therapy, but did respond to a combination of surgery and chemotherapy with rituximab and bendamustine.

Prevalence of clarithromycin-resistant Helicobacter pylori strains in gastric mucosa-associated lymphoid tissue lymphoma patients

Gastric MALT lymphoma is closely associated with Helicobacter pylori infection. Bacterial eradication therapy comprising clarithromycin is the first-line treatment in gastric MALT lymphoma patients. However, antimicrobial resistance to clarithromycin has been increasing in Europe, and thus far, it has not been examined in gastric MALT lymphoma patients. Based upon histopathological investigation, 17 adult gastric MALT lymphoma patients were identified to be related with H. pylori infection between 1997 and 2014. Detection of H. pylori infection in these patients and clarithromycin susceptibility testing were performed by 23S rRNA gene real-time PCR. Twelve of the patients were confirmed with H. pylori infection by real-time PCR. Among these patients, only two were found to be infected with clarithromycin-resistant H. pylori strain. In one of them, both the clarithromycin-resistant and sensitive genotype were detected. The rate of clarithromycin resistance was 15.4 %. Clarithromycin resistance pattern in gastric MALT lymphoma patients is under the predictions since a previous study performed in Central Europe revealed a rate of 36.6 % in Austria. Considering the low antimicrobial resistance rate, clarithromycin is still an option in gastric MALT lymphoma management.

Anatomic distribution, clinical features, and survival data of 87 cases primary gastrointestinal lymphoma

Background

The purpose of this study is to analyze the anatomic distribution, clinical features, therapeutic methods, and prognosis factors of primary gastrointestinal lymphoma (PGIL).

Methods

Clinical data of 87 cases PGIL in the First Affiliated Hospital of Dalian Medical University from January 1999 to December 2010 were collected. Follow-ups were made according to the clinical feature, pathological pattern, clinical stage, and therapeutic method. Kapan Meier method was used for the survival analysis. Log-rank test was used to perform univariate survival analysis. COX multivariate analysis was carried out to analyze factors of P < 0.05 in univariate survival analysis.

Results

The incidence of PGIL significantly increased in patients more than 40 years old (87.4 %). Clinical symptoms of PGIL were indistinguishable from other digestive system diseases, which included abdominal pain or discomfort (72.4 %), lack of appetite (16.3 %), gastrointestinal hemorrhage (14.9 %), and diarrhea (12.8 %). Some patients presented with systemic symptoms or complications, such as weight loss (35.6 %) and digestive tract obstruction (13.8 %). Primary gastric lymphoma (PGL) was the most common, followed by primary intestine lymphoma (PIL). The majority of PGIL were single lesion, which included 40 cases (87 %) PGL and 35 cases (94.5 %) PIL. The most frequent site of PGL was antrum of the stomach (43.5 %), as to PIL, the small intestine (90.2 %) was the most frequent site, especially within 100 cm far away from ileocecal valve. Most of PGIL were derived from B cell (93.1 %). The most common pathological type was mucosa-associated lymphoid tissue (MALT) (67.4 %) in the PGL group and diffuse large B cell lymphoma (DLBCL) (46.3 %) in the PIL group. Surgical treatment had been performed in most of PGIL, which included 32 cases in the PGL group and 38 cases in the PIL group. The 1-year overall survival (OS) and the 3-year OS were 82 and 77 %, respectively. Analysis of single factor affecting prognosis showed that lesion location, sources of cells, and clinical stage were associated with OS. PGL group had better OS than that of PIL group (1-year 89 vs 62 %, 3-year 84 vs 50 %, P = 0.03). B cell-originated group had better OS than that of T cell-originated group (1-year 89 vs 36 %, 3-year 85 vs 0 %, P = 0.008). Stage I + II group had better OS than that of stage III + IV group (1-year 89 vs 38 %, 3-year 87 vs 0 %, P = 0.007). Multivariate analysis showed that clinical stage and sources of cells were the significant independent prognostic factors.

Conclusions

It was more common to find location of PGIL in the stomach than that in the intestine. The most common pathological type was MALT in the PGL and DLBCL in the PIL. The treatment of PGL was focused on chemotherapy. It was noting that since PIL was not only difficult to make confirmed diagnosis but also likely to develop with complications, so it was usually needed surgical excision. Clinical stage and pathological pattern were related to prognosis of PGIL.

Different bismuth-based therapies for eradicating Helicobacter pylori: Randomized clinical trial of efficacy and safety

BACKGROUND AND OBJECTIVE

Bismuth salts are used for treating dyspepsia, and they exert antibacterial effects on Helicobacter pylori. This study aimed to compare the efficacy and safety of three bismuth-containing combination regimens for H. pylori eradication in a Turkish population.

METHODS

In this single-center study, 149 patients, who were diagnosed with H. pylori infection with urea breath test and histopathological examination, were randomized to receive the following therapies for 14 days: (1) bismuth-containing clarithromycin-based triple therapy (CBS-LAC), (2) bismuth-containing levofloxacin-based triple therapy (CBS-LAL), and (3) bismuth-containing quadruple therapy (BCQT). Eradication rates were evaluated six weeks after the treatment by performing intention to treat (ITT) and per protocol (PP) analyses. In addition, data on side effect profiles and patient compliance were collected.

RESULTS

PP and ITT analyses showed that eradication rates were 86% and 81.1%, respectively, with BCQT; 68.3% and 66.7%, respectively, with CBS-LAL therapy; and 65.3% and 59.3%, respectively, with CBS-LAC therapy. Eradication rates obtained using PP and ITT analyses were statistically significant for all the regimens.

CONCLUSION

Addition of bismuth to standard triple and levofloxacin-based regimen did not show an acceptable increase in eradication rates. Therefore, BCQT may be preferred for the first-line treatment of H. pylori infection.

Structural and biochemical characterization of GTP cyclohydrolase II from Helicobacter pylori reveals its redox dependent catalytic activity

GTP cyclohydrolase II (GCHII), catalyzes the conversion of GTP to 2,5-diamino-6-β-ribosyl-4(3H)-pyrimidinone-5'-phosphate and has been shown to be essential for pathogens. Here we describe the biochemical, kinetic and structural characterization of GCHII from Helicobacter pylori (hGCHII). The crystal structure of hGCHII, unlike other GCHII structures, revealed that cysteines at the active site existed in oxidized state forming two disulfide bonds and lacked Zn(2+) that was shown to be indispensable for catalytic activity in other species. However, incubation of hGCHII with hydrogen peroxide, an oxidizing agent, followed by PAR-assay showed that Zn(2+) was intrinsically present, indicating that all cysteines at the catalytic site remained in reduced state. Moreover, site directed mutagenesis of catalytic site cysteines revealed that only three, out of four cysteines were essential for hGCHII activity. These results, though, indicated that hGCHII crystallized in oxidized form, the expulsion of Zn(2+) upon oxidation of catalytic cysteines revealed its ability to act in response to the redox environment. Exploring further, incubation of hGCHII with reversible thiol modifying agent S-methyl-methane-thiosulfonate resulted in loss of GCHII activity due to oxidation of its cysteine residues as revealed by mass spectrometry studies. However, addition of reducing agent DTT partially restored the hGCHII catalytic activity. Taken together, these results demonstrate that hGCHII can regulate its catalytic activity depending on the redox environment, a function hitherto unknown for GCHII.

Rare gastrointestinal lymphomas: The endoscopic investigation

Gastrointestinal lymphomas represent up to 10% of gastrointestinal malignancies and about one third of non-Hodgkin lymphomas. The most prominent histologies are mucosa-associated lymphoid tissue lymphoma and diffuse large B-cell lymphoma. However, the gastrointestinal tract can be the site of rarer lymphoma subtypes as a primary or secondary localization. Due to their rarity and the multifaceted histology, an endoscopic classification has not been validated yet. This review aims to analyze the endoscopic presentation of rare gastrointestinal lymphomas from disease diagnosis to follow-up, according to the involved site and lymphoma subtype. Existing, new and emerging endoscopic technologies have been examined. In particular, we investigated the diagnostic, prognostic and follow-up endoscopic features of T-cell and natural killer lymphomas, lymphomatous polyposis and mantle cell lymphoma, follicular lymphoma, plasma cell related disease, gastrointestinal lymphomas in immunodeficiency and Hodgkin’s lymphoma of the gastrointestinal tract. Contrarily to more frequent gastrointestinal lymphomas, data about rare lymphomas are mostly extracted from case series and case reports. Due to the data paucity, a synergism between gastroenterologists and hematologists is required in order to better manage the disease. Indeed, clinical and prognostic features are different from nodal and extranodal or the bone marrow (in case of plasma cell disease) counterpart. Therefore, the approach should be based on the knowledge of the peculiar behavior and natural history of disease.

Endoscopic features of gastro-intestinal lymphomas: From diagnosis to follow-up

Many progresses have been done in the management of gastrointestinal (GI) lymphomas during last decades, especially after the discovery of Helicobacter pylori-dependent lymphoma development. The stepwise implementation of new endoscopic techniques, by means of echoendoscopy or double-balloon enteroscopy, enabled us to more precisely describe the endoscopic features of GI lymphomas with substantial contribution in patient management and in tailoring the treatment strategy with organ preserving approaches. In this review, we describe the recent progresses in GI lymphoma management from disease diagnosis to follow-up with a specific focus on the endoscopic presentation according to the involved site and the lymphoma subtype. Additionally, new or emerging endoscopic technologies that have an impact on the management of gastrointestinal lymphomas are reported. We here discuss the two most common subtypes of GI lymphomas: the mucosa-associated lymphoid tissue and the diffuse large B cell lymphoma. A general outline on the state-of-the-art of the disease and on the role of endoscopy in both diagnosis and follow-up will be performed.

Comparison of Helicobacter pylori eradication rates of standard 14-day quadruple treatment and novel modified 10-day, 12-day and 14-day sequential treatments

BACKGROUND & AIM

This study aimed to compare the efficacy and safety of bismuth-included standard regimen and modified sequential treatments in Turkey, where the success rate of standard triple therapy is very low.

METHODS

One-hundred and sixty patients with dyspeptic complaints and naïve Helicobacter pylori infection were randomized into four groups: 41 patients received standard 14-day quadruple treatment (STD) (Rabeprazole 20mg-bid, bismuth subcitrate (120 mg-qid), Tetracycline 500 mg-qid, Metronidazole 500 mg-tid) for 2 weeks. The modified sequential therapy groups received 20 mg rabeprazole and 1g amoxicillin, twice daily for the first 5 days, followed by Rabeprazole 20mg-bid, bismuth subcitrate (120 mg-qid), Tetracycline 500 mg-qid, Metronidazole 500 mg-tid for the remaining 5 (10 day sequential therapy group-10S) (42 patients), 7 (12 day sequential therapy group-12S) (42 patients) and 9 (14 day sequential therapy group-14S) (41 patients) days.

RESULTS

The overall compliance and H. pylori eradication rate among the 160 patients who completed the H. pylori eradication regimens were 86.9% (139/160) and 78.1% (125/160), respectively. The results were not statistically different between groups in the eradication rates. Per-protocol eradication rates were 76.5% in STD, 71.4% in 10S, 82.4% in 12S and 83.3% in 14S groups (p=0.7). Intention-to-treatment rates were 77.5% in STD, 72.5% in 10S, 82.5% in 12S and 80.0% in 14S groups (p=0.5).

CONCLUSION

The eradication rates of standard 14-day and different sequential quadruple treatment regimens are comparable and much more higher than with standard 14-day triple H. pylori eradication treatment that has been reported previously in Turkey.

Gastric MALT lymphoma: old and new insights

The stomach is the most frequent site of extranodal lymphoma. Gastric lymphoma originating from mucosa-associated lymphoid tissue (MALT) is typically a low-grade, B-cell neoplasia strongly associated with Helicobacter pylori (H. pylori) infection. Only certain H. pylori strains in some predisposed patients determine lymphoma development in the stomach, according to a strain-host-organ specific process. The clinical presentation is poorly specific, symptoms ranging from vague dyspepsia to alarm symptoms. Similarly, different endoscopy patterns have been described for gastric lymphoma. H. pylori eradication is advised as first-line therapy in early stage disease, and complete lymphoma remission is achieved in 75% of cases. Neoplasia stage, depth of infiltration in the gastric wall, presence of the API2-MALT1 translocation, localization in the stomach, and patient ethnicity have been identified as predictors of remission. Recent data suggests that H. pylori eradication therapy may be successful for gastric lymphoma treatment also in a small subgroup (15%) of H. pylori-negative patients. The overall 5-year survival and disease-free survival rates are as high as 90% and 75%, respectively. Management of patients who failed to achieve lymphoma remission following H. pylori eradication include radiotherapy, chemotherapy and, in selected cases, surgery.

Helicobacter pylori eradication and reflux disease onset: Did gastric acid get "crazy"?

Gastroesophageal reflux disease (GORD) is highly prevalent in the general population. In the last decade, a potential relationship between Helicobacter pylori (H. pylori) eradication and GORD onset has been claimed. The main putative mechanism is the gastric acid hypersecretion that develops after bacterial cure in those patients with corpus-predominant gastritis. We performed a critical reappraisal of the intricate pathogenesis and clinical data available in this field. Oesophagitis onset after H. pylori eradication in duodenal ulcer patients has been ascribed to a gastric acid hypersecretion, which could develop following body gastritis healing. However, the absence of an acid hypersecretive status in these patients is documented by both pathophysiology and clinical studies. Indeed, duodenal ulcer recurrence is virtually abolished following H. pylori eradication. In addition, intra-oesophageal pH recording studies failed to demonstrated increased acid reflux following bacterial eradication. Moreover, oesophageal manometric studies suggest that H. pylori eradication would reduce - rather than favor - acid reflux into the oesophagus. Finally, data of clinical studies would suggest that H. pylori eradication is not significantly associated with either reflux symptoms or erosive oesophagitis onset, some data suggesting also an advantage in curing the infection when oesophagitis is already present. Therefore, the legend of “crazy acid” remains - as all the others - a fascinating, but imaginary tale.

Standard triple and sequential therapies for Helicobacter pylori eradication: an update

H. pylori infection remains a worldwide spread disease with a definite morbidity and mortality. Unfortunately, no current therapy regimen is able to cure the infection in all treated patients. The efficacy of the widely recommended triple therapies is decreasing, and a novel 10-day sequential therapy has been proposed. Data of 3 previous meta-analyses showed a significantly higher eradication rate following the sequential as compared to the 7-10 days triple therapies. The sequential therapy achieved significantly better results than triple therapies in children, elderly patients, non-ulcer dyspepsia patients, and in those infected with resistant strains towards either clarithromycin or metronidazole. We identified further 10 randomized trials. By pooling data, H. pylori infection was cured in 2,454 (86%; 95% CI: 84.7-87.3) out of 2,853 patients with the sequential therapy and in 2,320 (75.3%; 95% CI: 73.8-76.9) out of 3,079 patients treated with standard triple therapies (p<0.001), corresponding to a number to treat (NNT) of 9. The comparison between the 10-day sequential regimen and 14-day triple therapies deserves further investigations.

Modified sequential therapy regimens for Helicobacter pylori eradication: a systematic review

BACKGROUND

Different modified sequential therapies have been proposed for Helicobacter pylori eradication. However, the efficacy of these regimens is controversial.

METHODS

We performed a systematic review of the literature and pooled-data analysis to assess: (a) the efficacy of different modified sequential therapies for H. pylori eradication, (b) the eradication rates achieved by these regimens as compared to either standard triple therapies or standard sequential regimen when available.

RESULTS

Overall 21 trials met inclusion criteria. The most used modified sequential therapy was the seven plus seven tetracycline-based regimen which achieved an overall 73.3% eradication rate (6 trials). Such therapy was more effective than the 14-day triple therapy (77.2% vs. 63.6%; 3 trials). The most used five plus five levofloxacin-based sequential therapy achieved a 95.8% and 90% cure rates when 250 mg and 500 mg levofloxacin twice daily were used, respectively. These success rates were higher as compared to that of either standard sequential or triple therapies. Other modified sequential therapies did not achieved acceptably high cure rates. Contradictory results emerged from 2 studies assessing the efficacy of a levofloxacin-based sequential regimen as a second-line therapy.

CONCLUSIONS

Both levofloxacin- and tetracycline-based sequential therapies have been proved to be more effective than standard triple therapies, confirming that the 'sequential' administration of drugs is a successful therapeutic procedure for H. pylori infection.

Helicobacter pylori therapy: Present and future

Helicobacter pylori (H. pylori) plays a crucial role in the pathogenesis of chronic active gastritis, peptic ulcer and gastric mucosa-associated lymphoid tissue-lymphoma, and is also involved in carcinogenesis of the stomach. H. pylori treatment still remains a challenge for physicians, since no current first-line therapy is able to cure the infection in all treated patients. Several factors may help in the eradication of therapy failure. We reviewed both bacterial and host factors involved in therapeutic management of the H. pylori infection. In addition, we evaluated data on the most successful therapy regimens - sequential and concomitant therapies - currently available for H. pylori eradication.

Gastrointestinal lymphomas in a North American population: clinicopathologic features from one major Central-Midwestern United States tertiary care medical center

BACKGROUND

Gastrointestinal (GI) lymphomas are very common types of extranodal lymphomas, and we hypothesize there are regional differences in subtype, distribution in the GI tract, and epidemiological features among the different populations.

METHODS

We retrospectively evaluated the clinical, molecular and histologic features of North American primary and secondary GI lymphomas diagnosed from 2000-2009 seen at our institution. We utilized immunohistochemistry and fluorescence in situ hybridization to further evaluate a subset of the gastric lymphomas.

RESULTS

Extranodal marginal zone lymphomas of mucosal associated lymphoid tissue (MALTs) and diffuse large B cell lymphomas (DLBCLs) were the most common subtypes of GI lymphomas. Select gastric DLBCLs (N = 6) and MALTs (N = 13) were further examined for API2-MALT1 and IGH translocations, and P16 and P53 protein expression. Gastric MALTs showed frequent API2-MALT1 (38%) but not IGH translocations (0%), and the DLBCLs showed neither translocation. Expression of P16 and P53 proteins and the proliferative index were compared between high grade gastric lymphomas (gastric DLBCLs) and low grade gastric lymphomas (gastric MALTs). P53 overexpression (P = 0.008) and a high proliferation index [Ki-67] (P = 0.00042) were significantly associated with gastric DLBCL, but no statistically significant difference was observed in P16 expression (p = 0.108) between gastric DLBCL and gastric MALT.

CONCLUSION

Our study revealed that GI lymphomas from a Central-Midwestern North American population showed differences and similarities to non-North American cohorts. In addition, API2-MALT1, P16 and P53 abnormalities occurred frequently in gastric lymphomas from this North American population.

VIRTUAL SLIDES

The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1415505838687793.

Lack of association of conjunctival MALT lymphoma with Chlamydiae or Helicobacter pylori in a cohort of Chinese patients

BACKGROUND

This study was conducted to detect microbial pathogens in conjunctival mucosa-associated lymphoid tissue (MALT) lymphoma specimens in an attempt to determine possible associations between conjunctival MALT lymphoma and microbial infections.

MATERIAL/METHODS

Using PCR technique, freshly obtained tumor specimens from 16 cases of conjunctival MALT lymphoma, as confirmed by postoperative pathology, were analyzed for DNA of Chlamydia psittaci (C. psittaci), Chlamydia trachomatis (C. trachomatis), Chlamydia pneumoniae (C. pneumoniae) and Helicobacter pylori (H. pylori). Synthetic C. psittaci, C. trachomatis, C. pneumoniae and H. pylori DNA were used as positive control, and blank plasmid DNA as negative control.

RESULTS

Electrophoresis showed that no bands corresponding to the positive control were observed in the specimens, indicating that no DNA of the 4 microorganisms was detected in the specimens of the 16 cases of conjunctival MALT lymphoma.

CONCLUSIONS

The PCR technique was able to detect the positive control quickly and accurately, but the results of PCR in analyzing the 16 specimens were negative, indicating that there is no association between conjunctival MALT lymphoma and the 4 microorganisms in Chinese patients.

A case of gastric mucosa-associated lymphoid tissue lymphoma in which magnified endoscopy with narrow band imaging was useful in the diagnosis

Recently, we reported a case of gastric mucosa-associated lymphoid tissue (MALT) lymphoma presenting with unique vascular features. In the report, we defined the tree-like appearance (TLA) on the images of abnormal blood vessels which resembled branches from the trunk of a tree in the shiny mucosa, in which the glandular structure was lost. The 67-year-old female was diagnosed with gastric MALT lymphoma. The patient received eradication therapy for H. pylori. Conventional endoscopy revealed multiple ill-delineated brownish depressions in the stomach and cobblestone-like mucosa was observed at the greater curvature to the posterior wall of the upper gastric body 7 mo after successful eradication. Unsuccessful treatment of gastric MALT lymphoma was suspected on conventional endoscopy. Conventional endoscopic observations found focal depressions and cobblestone-like appearance, and these lesions were subsequently observed using magnified endoscopy combined with narrow band imaging to identify abnormal vessels presenting with a TLA within the lesions. Ten biopsies were taken from the area where abnormal vessels were present within these lesions. Ten biopsies were also taken from the lesions without abnormal vessels as a control. A total of 20 biopsy samples were evaluated to determine whether the diagnosis of MALT lymphoma could be obtained histologically from each sample. A positive diagnosis was obtained in 8/10 TLA (+) sites and in 2/10 TLA(-) sites. Target biopsies of the site with abnormal blood vessels can potentially improve diagnostic accuracy of gastric MALT lymphoma.

Chlamydia psittaci in ocular adnexa MALT lymphoma: a possible role in lymphomagenesis and a different geographical distribution

Ocular adnexa MALT-lymphomas represent approximatively 5-15% of all extranodal lymphomas. Almost 75% of OAMLs are localized in orbital fat, while 25% of cases involves conjunctive. MALT-lymphomas often recognize specific environmental factors responsible of lymphoma development and progression. In particular as Helicobacter pylori in gastric MALT lymphomas, other bacterial infections have been recognized related to MALT lymphomas in specific site. Recently Chlamydia psittaci has been identified in Ocular Adnexa MALT lymphomas, with variable frequence dependently from geographic areas. Thus bacterial infection is responsible of clonal selection on induced MALT with subsequent lymphoma development. Moreover Chlamydia psittaci could promote chromosomal aberration either through genetic instability as a consequence of induced proliferation and probably through DNA oxidative damage. The most common translocation described in MALT lymphomas affects NF-kB pathway with a substantial antiapoptotic effect. Several therapeutic approaches are now available, but the use of antibiotic-therapy in specific cases, although with conflicting results, could improve the treatment of ocular adnexa MALT lymphomas. In this review we analyse the most relevant features of Ocular adnexa MALT lymphomas, underlining specific biological characteristics mainly related to the potential role of Chlamydia psittaci in lymphomagenesis.

MicroRNA-200 is commonly repressed in conjunctival MALT lymphoma, and targets cyclin E2

BACKGROUND

Aberrant microRNA expression is implicated in cancer initiation and progression. We sought to identify dysregulated miRNAs in conjunctival mucosa-associated lymphoid tissue (MALT) lymphoma, and investigated their biological significance.

METHODS

The profiles of miRNAs in conjunctival MALT lymphoma and normal adjacent tissues were investigated by microRNA microarray of four pairs of surgically removed conjunctival MALT lymphoma tissues and matched controls. The results of microarray were further confirmed in 14 paired conjunctival MALT lymphoma samples (including the former four pairs) using quantitative RT-PCR. The functional effect of miR-200 was examined further. A luciferase reporter assay was performed to confirm the predicted target.

RESULTS

The microarray results revealed upregulated miR-150/155, and downregulated miR-184, miR-200a, b, c, and miR-205. These findings were confirmed by quantitative RT-PCR. Targetscan analysis suggested cyclin E2 as potential target of miR-200a, b, c. Luciferase reporter assay using vectors containing the 3'UTR of cyclin E2 showed that miR-200a, b, c could suppress luciferase activities. RT-PCR and immunoblotting studies revealed that overexpression of miR-200a, b, c reduced the mRNA and protein levels of cyclin E2 respectively.

CONCLUSIONS

We demonstrated that miRNAs were dysregulated in conjunctival MALT lymphoma, and dysregulation of the miR-200 family could be involved in the pathogenesis and progression of the disease.

Review article: common misconceptions in the management of Helicobacter pylori-associated gastric MALT-lymphoma

BACKGROUND

Helicobacter pylori infection is the main cause of gastric mucosa-associated lymphoid tissue (MALT) lymphoma.

AIM

To review several common misconceptions in the management of H. pylori-associated gastric MALT-lymphoma.

METHODS

Bibliographical searches were performed in MEDLINE up to June 2011.

RESULTS

If adequate diagnostic methods are used, and if only low-grade lymphomas are considered, the prevalence of H. pylori infection is very high (almost 90%). H. pylori eradication is effective in treating approximately 80% of patients with early stage lymphoma. In H. pylori-positive gastric high-grade lymphomas, antibiotic therapy should always be prescribed, as approximately 50% of them regress after H. pylori eradication. Patients with early stage MALT lymphoma negative for H. pylori might still benefit from antibiotic treatment as the sole treatment. Complete remission of gastric MALT lymphoma after H. pylori eradication can take even >12 months. PCR assay for the detection of monoclonal B cells remains positive in many cases after complete remission has been reached. Patients with a persistent clonal band should not be treated unless the lymphoma can be histologically demonstrated. Synchronous occurrence of gastric adenocarcinoma and MALT lymphoma has been repeatedly reported. In some patients in complete remission, eradication of H. pylori does not prevent later development of early gastric cancer. Gastric lymphoma recurrence occurs in some patients after both bacterial and lymphoma regression. H. pylori reinfection does not constitute a prerequisite for lymphoma recurrence.

CONCLUSIONS

The present article states several misconceptions in the management of H. pylori-associated gastric MALT-lymphoma in clinical practice, reviews the related scientific evidence and proposes the adequate attitude in each case.

Pulmonary histoplasmosis producing a spindle cell "pseudotumor"

Pulmonary spindle cell proliferations have been reported in association with a limited group of infectious agents. These lesions are rare and identified most often in the setting of immunosuppression. Because their appearance can simulate a spindle cell neoplasm, they are diagnostically treacherous, sometimes delaying antimicrobial therapy or resulting in unnecessary surgery. We report a case of a spindle pseudotumor of the lung resulting from Histoplasma capsulatum infection, a previously unreported cause of a spindle cell lesion in the lung. The patient was a 67-year-old woman in whom positron emission tomography-positive nodules developed in the left lung and left mediastinum. The patient had undergone renal transplantation and was receiving immunosuppressive therapy with mycophenolate, tacrolimus, and low-dose prednisone. Infection with H capsulatum was confirmed by culture of pleural effusion fluid, DNA probe analysis of the pleural fluid culture isolate, urinary Histoplasma antigen detection, and Grocott methenamine silver stains of tissue sections. To our knowledge, this is the first case of a spindle cell "pseudotumor" of the lung resulting from histoplasmosis. It highlights the importance of performing special stains for organisms when evaluating pulmonary spindle cell lesions in an immunocompromised host.