Arzu Ensari

Management of precancerous conditions and lesions in the stomach (MAPS): guideline from the European Society of Gastrointestinal Endoscopy (ESGE), European Helicobacter Study Group (EHSG), European Society of Pathology (ESP), and the Sociedade Portuguesa de Endoscopia Digestiva (SPED)

Atrophic gastritis, intestinal metaplasia, and epithelial dysplasia of the stomach are common and are associated with an increased risk for gastric cancer. In the absence of guidelines, there is wide disparity in the management of patients with these premalignant conditions. The European Society of Gastrointestinal Endoscopy (ESGE), the European Helicobacter Study Group (EHSG), the European Society of Pathology (ESP) and the Sociedade Portuguesa de Endoscopia Digestiva (SPED) have therefore combined efforts to develop evidence-based guidelines on the management of patients with precancerous conditions and lesions of the stomach (termed MAPS). A multidisciplinary group of 63 experts from 24 countries developed these recommendations by means of repeat online voting and a meeting in June 2011 in Porto, Portugal. The recommendations emphasize the increased cancer risk in patients with gastric atrophy and metaplasia, and the need for adequate staging in the case of high grade dysplasia, and they focus on treatment and surveillance indications and methods.

KRAS mutation testing for predicting response to anti-EGFR therapy for colorectal carcinoma: proposal for an European quality assurance program.

Novel therapeutic agents targeting the epidermal growth factor receptor (EGFR) have improved outcomes for patients with colorectal carcinoma. However, these therapies are effective only in a subset of patients. Activating mutations in the KRAS gene are found in 30–40% of colorectal tumors and are associated with poor response to anti-EGFR therapies. Thus, KRAS mutation status can predict which patient may or may not benefit from anti-EGFR therapy. Although many diagnostic tools have been developed for KRAS mutation analysis, validated methods and standardized testing procedures are lacking. This poses a challenge for the optimal use of anti-EGFR therapies in the management of colorectal carcinoma. Here we review the molecular basis of EGFR-targeted therapies and the resistance to treatment conferred by KRAS mutations. We also present guideline recommendations and a proposal for a European quality assurance program to help ensure accuracy and proficiency in KRAS mutation testing across the European Union.

The future of the TNM staging system in colorectal cancer: time for a debate?

TNM staging has made a major contribution to the clinical management of patients with cancer over the past 50 years, but are we sure it delivers what is needed to provide adequate advice in the 21st century, and are there ways in which the system can be improved? This article, by pathologists with a special interest in colorectal cancer, is intended to offer constructive criticism towards the TNM classification of colorectal cancer, make suggestions for improvement, and recommend the adoption of a robust evidence base for this system.

Early-onset inflammatory bowel disease and common variable immunodeficiency–like disease caused by IL-21 deficiency

BACKGROUND Alterations of immune homeostasis in the gut can result in development of inflammatory bowel disease (IBD). Recently, Mendelian forms of IBD have been discovered, as exemplified by deficiency of IL-10 or its receptor subunits. In addition, other types of primary immunodeficiency disorders might be associated with intestinal inflammation as one of their leading clinical presentations. OBJECTIVE We investigated a large consanguineous family with 3 children who presented with early-onset IBD within the first year of life, leading to death in infancy in 2 of them. METHODS Homozygosity mapping combined with exome sequencing was performed to identify the molecular cause of the disorder. Functional experiments were performed to assess the effect of IL-21 on the immune system. RESULTS A homozygous mutation in IL21 was discovered that showed perfect segregation with the disease. Deficiency of IL-21 resulted in reduced numbers of circulating CD19(+) B cells, including IgM(+) naive and class-switched IgG memory B cells, with a concomitant increase in transitional B-cell numbers. In vitro assays demonstrated that mutant IL-21(Leu49Pro) did not induce signal transducer and activator of transcription 3 phosphorylation and immunoglobulin class-switch recombination. CONCLUSION Our study uncovers IL-21 deficiency as a novel cause of early-onset IBD in human subjects accompanied by defects in B-cell development similar to those found in patients with common variable immunodeficiency. IBD might mask an underlying primary immunodeficiency, as illustrated here with IL-21 deficiency.

Prevalence of Celiac Disease in Healthy Turkish School Children

OBJECTIVES:Epidemiological studies of celiac disease (CD) in Turkey have been performed only within some regions of the country. The aim of this study was to determine the prevalence of CD in Turkish school children.METHODS:Between 2006 and 2008, serum samples were collected from 20,190 students (age range, 6–17 years) in 139 schools in 62 cities from different regions of Turkey. CD was screened using IgA antitissue transglutaminase (IgA-tTG) and total serum IgA. Subjects with selective IgA deficiency were further tested for IgG-tTG. Serum samples positive for IgA or IgG-tTG were further tested for IgA antiendomysial antibodies (IgA-EMAs) using an indirect immunofluorescence method. Small-intestinal biopsy was offered to all subjects with tTG antibody positivity.RESULTS:Of the 20,190 subjects, 489 were antibody positive (IgA-tTG only in 270, both IgA-tTG and IgA-EMA in 215, and IgG-tTG in 4). Selective IgA deficiency was detected in 108 patients, and 4 of them were positive for IgG-tTG. An intestinal biopsy was conducted in 215 subjects (IgA-tTG positive in 110, IgA-tTG and IgA-EMA positive in 104, and IgG-tTG positive in 1). The biopsy findings of 95 children were consistent with CD. Thus, the estimated biopsy-proven prevalence was 1:212 children. The positive predictive value (PPV) for IgA-tTG plus EMA was 75.9%. PPV was 44.3% when only IgA-tTG was used.CONCLUSIONS:We estimate that the prevalence of CD is at least 0.47% in healthy Turkish school children. Screening for IgA-tTG plus EMA provided better results for diagnosis when compared with testing for IgA-tTG alone.

Serrated polyps of the colon: how reproducible is their classification?

For several years, the lack of consensus on definition, nomenclature, natural history, and biology of serrated polyps (SPs) of the colon has created considerable confusion among pathologists. According to the latest WHO classification, the family of SPs comprises hyperplastic polyps (HPs), sessile serrated adenomas/polyps (SSA/Ps), and traditional serrated adenomas (TSAs). The term SSA/P with dysplasia has replaced the category of mixed hyperplastic/adenomatous polyps (MPs). The present study aimed to evaluate the reproducibility of the diagnosis of SPs based on currently available diagnostic criteria and interactive consensus development. In an initial round, H&E slides of 70 cases of SPs were circulated among participating pathologists across Europe. This round was followed by a consensus discussion on diagnostic criteria. A second round was performed on the same 70 cases using the revised criteria and definitions according to the recent WHO classification. Data were evaluated for inter-observer agreement using Kappa statistics. In the initial round, for the total of 70 cases, a fair overall kappa value of 0.318 was reached, while in the second round overall kappa value improved to moderate (kappa = 0.557; p < 0.001). Overall kappa values for each diagnostic category also significantly improved in the final round, reaching 0.977 for HP, 0.912 for SSA/P, and 0.845 for TSA (p < 0.001). The diagnostic reproducibility of SPs improves when strictly defined, standardized diagnostic criteria adopted by consensus are applied.

Evidence-based medicine: the time has come to set standards for staging.

For international communication in cancer, staging systems such as TNM are essential; however, the principles and processes used to decide about changes in every new edition of TNM need to be subject to debate. Changes with major impact for patient treatment are introduced without evidence. We think that TNM should be a continual reactive process, rather than a proactive process. Changes should only occur after extensive discussion within the community, and before the introduction of any changes these should be tested for reproducibility and compared to the currently used gold standard. TNM should not be used to test hypotheses. It should introduce established facts that are beneficial to predicting patient prognosis. TNM should thus be restructured on a basis equivalent to evidence‐based guidelines. The strength of the evidence should be explicitly stated and the evidence base given. It is time for the principles of staging to be widely debated and new principles and processes to be introduced to ensure that we are not in the same situation in the future. The disparity between therapeutic decision making and TNM staging is marked and we would appeal for the radical overhaul of TNM staging to make it fit for the twenty‐first century. TNM is central to the management of cancer patients and we must protect and enhance its reputation. Copyright

Histology of microscopic colitis—review with a practical approach for pathologists

Microscopic colitis has emerged as a major cause of chronic watery non‐bloody diarrhoea, particularly in elderly females. The term is used as an umbrella term to categorize a subgroup of colitides with distinct clinicopathological phenotypes and no significant endoscopic abnormalities. Lymphocytic colitis is defined by an increased number of surface intraepithelial lymphocytes, and collagenous colitis by a thickened collagen band underneath the surface epithelium. There is increased inflammation in the lamina propria, but only little or no crypt architectural distortion. Incomplete and variant forms showing less characteristic features have been reported under different names. The differential diagnosis mainly includes resolving infectious colitis and changes related to the intake of drugs such as non‐steroidal anti‐inflammatory drugs. Substantial clinical and histological overlap between lymphocytic and collagenous colitis has been described, raising the suspicion that the conditions are two histological manifestations of the same entity, possibly representing different manifestations during the disease course or different stages of disease development. In this review, we provide a practical approach for pathologists, with a focus on diagnostic criteria and differential diagnosis, and discuss recent insights into the pathogenesis of disease and the relationship with classic chronic inflammatory bowel disease, i.e. Crohns disease and ulcerative colitis.

An unusual presentation of helicobacter pylori infection: so-called “Russell body gastritis”

Helicobacter pylori (H. pylori) is a “slow” bacterial pathogen, which induces several gastroduodenal diseases. Varying degrees of inflammation can be present in the gastric mucosa of patients infected with H. pylori. The case presented here is a male patient suffering from dyspepsia and nausea. His upper gastrointestinal endoscopy revealed pan gastritis. Histological examination of multiple gastric biopsies taken from the body and antrum showed a rare morphological expression of H. pylori gastritis characterized by diffuse plasma cell infiltration with extensive Russell body formation. Diffuse infiltration of plasma cells with Russell bodies in gastric mucosa can cause difficulties in differentiation from neoplastic processes. However, immunohistochemically, the infiltrating cells in the gastric mucosa stained negatively with cytokeratins while they expressed both kappa and lambda light chains showing their polyclonal nature. The presence of diffuse plasma cells with Russell bodies in the gastric mucosa may represent a different presentation of H. pylori gastritis. There are only two case reports of similar presentation and both have been called “Russell body gastritis”.

Barrett's esophagus: Prevalence and its relationship with dyspeptic symptoms

Background and Aim:  Barretts metaplasia is a premalign condition which plays a pivotal role in the development of esophageal adenocarcinoma. It is considered a complication of chronic gastroesophageal reflux disease. Although esophageal adenocarcinoma is an uncommon cancer, its incidence is rapidly increasing. The aims of the present study were to determine the prevalence of Barretts metaplasia in outpatients referred for gastroscopy for upper gastrointestinal symptoms, and to clarify the relationship between Barretts metaplasia and upper gastrointestinal symptoms.