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The clinical history and histological features of seven cases of granulomatous mastitis are presented. The lesion occurs in young parous women as a tender extra-areolar breast lump. Histologically, non-caseating discrete granulomas are present, confined to breast lobules with, in three cases, coalescence of the granulomas and microabscess formation. Pathogenesis of the changes is discussed. It is thought that granulomatous mastitis is an entity morphologically distinct from duct ectasia/plasma cell mastitis and the commoner forms of granulomatous breast diseases. [ABSTRACT FROM PUBLISHER]

Background & Aims: Histopathology is an emerging treatment target in ulcerative colitis (UC) clinical trials. Our aim was to provide guidance on standardizing biopsy collection protocols, identifying optimal evaluative indices, and defining thresholds for histologic response and remission after treatment., Methods: An international, interdisciplinary expert panel of 19 gastroenterologists and gastrointestinal pathologists was assembled. A modified RAND/University of California, Los Angeles appropriateness methodology was used to address relevant issues. A total of 138 statements were derived from a systematic review of the literature and expert opinion. Each statement was anonymously rated as appropriate, uncertain, or inappropriate using a 9-point scale. Survey results were reviewed and discussed before a second round of voting., Results: Histologic measurements collected using a uniform biopsy strategy are important for assessing disease activity and determining therapeutic efficacy in UC clinical trials. Multiple biopsy strategies were deemed acceptable, including segmental biopsies collected according to the endoscopic appearance. Biopsies should be scored for architectural change, lamina propria chronic inflammation, basal plasmacytosis, lamina propria and epithelial neutrophils, epithelial damage, and erosions/ulcerations. The Geboes score, Robarts Histopathology Index, and Nancy Index were considered appropriate for assessing histologic activity; use of the modified Riley score and Harpaz Index were uncertain. Histologic activity at baseline should be required for enrollment, recognizing this carries operational implications. Achievement of histologic improvement or remission was considered an appropriate and realistic therapeutic target. Current histologic indices require validation for pediatric populations., Conclusions: These recommendations provide a framework for standardized implementation of histopathology in UC trials. Additional work is required to address operational considerations and areas of uncertainty., (Copyright © 2021 AGA Institute. Published by Elsevier Inc. All rights reserved.)

There are few abbreviations in surgical pathology that are associated with as much immediate recognition, frustration, and confusion as DALM (dysplasia-associated lesion or mass). DALM is used to describe endoscopically visible dysplastic lesions in the surveillance of patients with inflammatory bowel disease. However, the diagnosis of DALM has been complicated by the inconsistent criteria and use of terminology for describing dysplasia in inflammatory bowel disease, and a tendency to relate DALM with the need for colectomy. Fortunately, advancements in both endoscopic visualization and local excision capability have allowed for a more defined management of dysplasia in inflammatory bowel disease. In 2015, the Surveillance for Colorectal Endoscopic Neoplasia Detection and Management in Inflammatory Bowel Disease Patients International Consensus Recommendations (SCENIC) Development Panel, a panel of predominantly expert gastroenterologists and endoscopists in surveillance of inflammatory bowel disease, published a consensus statement. One recommendation was to abandon DALM-related terminology in favor of endoscopic descriptors modified from the Paris endoscopic classification. Recommendations on surveillance and management of dysplastic lesions were also provided. Nevertheless, interval carcinomas and metachronous neoplasia remain persistent issues. This review aims to provide an update on the post-DALM terminology and management recommendations for inflammatory bowel disease-associated dysplasia necessary for a meaningful communication between pathologists and clinicians.

Puprpose: Benign polyps that are technically challenging and unsafe to remove via polypectomy are known as complex polyps. Concerns regarding safety and completeness of resection dictate they undergo advanced endoscopic techniques, such as endoscopic mucosal resection or surgery. We provide a comprehensive overview of complex polyps and current treatment options., Methods: A review of the English literature was conducted to identifyarticles describing the management of complex polyps of the colon and rectum., Results: Endoscopic mucosal resection is the standard of care for the majority of complex polyps. Only polyps that fail endoscopic mucosal resection or are highly suspicious of invasive cancer but which cannot be removed endoscopically warrant surgery., Conclusion: Several factors influence the treatment of a complex polyp; therefore, there cannot be a "one-size-fitsall" approach. Treatment should be tailored to the lesion's characteristics, the risk of adverse events, and the resources available to the treating physician.

Tumour budding in colorectal cancer is an important prognostic factor. A recent consensus conference elaborated recommendations and key issues for future studies, among those the use of pan-cytokeratin stains, especially in stage II patients. We report the first prospective diagnostic experience using pan-cytokeratin for tumour budding assessment. Moreover, we evaluate tumour budding using pan-cytokeratin stains and disease-free survival (DFS) in stage II patients. To this end, tumour budding on pan-cytokeratin-stained sections was evaluated by counting the number of tumour buds in 10 high-power fields (0.238 mm 2 ), then categorizing counts as low/high-grade at a cut-off of 10 buds, in two cohorts. Cohort 1: prospective setting with 236 unselected primary resected colorectal cancers analysed by 17 pathologists during diagnostic routine. Cohort 2: retrospective cohort of 150 stage II patients with information on DFS. In prospective analysis of cohort 1, tumour budding counts correlated with advanced pT, lymph node metastasis, lymphovascular invasion, perineural invasion (all p  < 0.0001), and distant metastasis ( p  = 0.0128). In cohort 2, tumour budding was an independent predictor of worse DFS using counts [ p  = 0.037, HR (95% CI): 1.007 (1.0-1.014)] and the low-grade/high-grade scoring approach [ p  = 0.02; HR (95% CI): 3.04 (1.2-7.77), 90.7 versus 73%, respectively]. In conclusion, tumour budding assessed on pan-cytokeratin slides is feasible in a large pathology institute and leads to expected associations with clinicopathological features. Additionally, it is an independent predictor of poor prognosis in stage II patients and should be considered for risk stratification in future clinical studies.

Background: In patients with ulcerative colitis (UC), mucosal healing has emerged as a major therapeutic goal, and is usually assessed endoscopically. Histological healing does not correlate very well with endoscopic mucosal healing in UC and persistent histological inflammation might be a better predictor of future clinical relapse than the endoscopic appearance alone., Aim: To define how histological assessment of disease activity should be best done in UC., Methods: Electronic (PubMed/Embase) and manual search., Results: At least 18 histological indices to assess disease activity in UC have been described, though none are fully validated. However, histological assessment is increasingly used as a secondary endpoint in clinical trials in UC. After reviewing and discussing existing histological scoring systems for UC activity, we describe features of histological response and define three grades of activity: (i) histological healing - complete resolution of abnormalities; (ii) quiescent disease, - lack of mucosal neutrophils but chronic inflammation may remain; (iii) active disease - presence of neutrophils plus possible epithelial damage. It is recommended that two biopsies are taken from each colonic segment which should include always biopsy of the rectum and the most affected segments. There is to date no agreed preferable scoring system but the Geboes Index is the best validated (kappa for interobserver variation 0.59-0.70)., Conclusion: Histological assessment of disease activity in UC is increasingly used, but needs to be carefully defined., (© 2015 John Wiley & Sons Ltd.)

Venous invasion (VI) is a well-established independent prognostic indicator in colorectal cancer (CRC). Its accurate detection is particularly important in stage II CRC as it may influence the decision to administer adjuvant therapy. The Royal College of Pathologists (RCPath) of the United Kingdom state that VI should be detected in at least 30% of CRC resection specimens. However, our experience in Ontario, Canada suggests that this (conservative) benchmark is rarely met. This article highlights the "Ontario experience" with respect to VI reporting and the key role that careful morphologic assessment, elastin staining and knowledge transfer has played in improving VI detection provincially and beyond.

Bone morphogenetic proteins (BMPs) are a group of growth factors with dual functions in cancer development and progression. Recently, certain tumor-promoting roles have been identified for selected antagonists/inhibitors (BMPIs) of this developmental pathway. A recent focus on the implication of BMP in colorectal cancer progression has emerged, mainly due to the presence of inactivating mutations in several members of the canonical signaling cascade. However, the detailed expression profiles of BMPIs remain largely unknown. Based on our previous work, whereby three specific BMPIs, gremlin-1 (GREM1), high-temperature requirement A3 (HTRA3) and follistatin (FST) were collectively overexpressed in desmoplastic cocultures of colorectal cancer (CRC), here, we undertook an immunohistochemical approach to describe the patterns of their expression in CRC patients. Two major characteristics described the BMPI expression signature: First, the synchronous and coordinated stromal and epithelial overexpression of individual BMPIs in desmoplastic lesions, which demonstrated that all three of them contribute to increasing levels of BMP antagonism in such areas. Second, the presence of microenvironmental polarity in the BMPI pattern of expression, which was indicated through the preferential expression of HTRA3 in the stromal, and the parallel FST/GREM1 expression in the epithelial component of the investigated sections. In addition, expression of HTRA3 in the epithelial compartment of the tumors demonstrated a significant predictive power to discriminate between tumor-budding-bearing and tumor-budding-free desmoplastic microenvironments. Together, these findings contribute to the understanding of signaling dynamics of BMP antagonism in the colorectal cancer desmoplastic invasion front., (Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.)

It has been suggested that cancer-associated fibroblasts (CAFs) positioned at the desmoplastic areas of various types of cancer are capable of executing a migratory program, characterized by accelerated motility and collective configuration. Since CAFs are reprogrammed derivatives of normal progenitors, including quiescent fibroblasts, we hypothesized that such migratory program could be context-dependent, thus being regulated by specific paracrine signals from the adjacent cancer population. Using the traditional scratch assay setup, we showed that only specific colon cancer cell lines (i.e. HT29) were able to induce collective CAF migration. By performing quantitative proteomics (SILAC), we identified a 2.7-fold increase of claudin-11, a member of the tight junction apparatus, in CAFs that exerted such collectivity in their migratory pattern. Further proteomic investigations of cancer cell line secretomes revealed a specific signature, involving TGF-β, as potential mediator of this effect. Normal colonic fibroblasts stimulated with TGF-β exerted myofibroblastic differentiation, occludin (OCLN) and claudin-11 (CLDN11) overexpression and cohort formation. Subsequently, inhibition of TGF-β attenuated all the previous effects. Immunohistochemistry of the universal tight junction marker occludin in a cohort of 30 colorectal adenocarcinoma patients defined a CAF subpopulation expressing tight junctions. Overall, these data suggest that cancer cells may induce CLDN11 overexpression and subsequent collective migration of peritumoral CAFs via TGF-β secretion., (Copyright © 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.)

Surveillance for neoplasia in colitis is the most challenging diagnostic colonoscopic procedure. The detection and treatment of colorectal dysplasia in inflammatory bowel disease remain problematic to the point that unsuspected colorectal cancers (CRCs) are still identified. Excellent bowel preparation and use of high-resolution colonoscopes with chromoendoscopy facilitate the detection and characterization of subtle neoplasia. This approach is superior to taking random biopsy specimens and should be the standard of care for surveillance but requires adequate training. Suspicious lesions should be assessed carefully and described using objective terminology. The terms dysplasia-associated lesions/masses and flat dysplasia are best avoided because they may be open to misinterpretation. Most suspicious lesions detected during surveillance can be removed endoscopically, precluding the need for surgery. Nevertheless, endotherapy in colitis can be difficult as a result of underlying inflammation and scarring. Lesions that are not endoscopically resectable need to be removed surgically, although the possibility that some lesions might be amenable to local resection (including lymphadenectomy) rather than subtotal colectomy may need to be re-evaluated. Despite surveillance programs, patients still present clinically with CRC. This may occur because lesions are missed (possibly because of the failure to use optimal techniques), lesions are not adequately removed, patients fail to return for colonoscopy, or CRCs arise rapidly in mucosa that is minimally dysplastic and the CRCs are not recognized as being potentially invasive even on biopsy. Future advances in, for example, stool DNA assays, use of confocal endomicroscopy, or use of endoscopic ultrasound, may help in the identification of high-risk patients and the assessment of dysplastic lesions., (Copyright © 2014 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Neoplastic cells recruit fibroblasts through various growth factors and cytokines. These "cancer-associated fibroblasts" (CAF) actively interact with neoplastic cells and form a myofibroblastic microenvironment that promotes cancer growth and survival and supports malignancy. Several products of their paracrine signaling repertoire have been recognized as tumor growth and metastasis regulators. However, tumor-promoting cell signaling is not the only reason that makes CAFs key components of the "tumor microenvironment," as CAFs affect both the architecture and growth mechanics of the developing tumor. CAFs participate in the remodeling of peritumoral stroma, which is a prerequisite of neoplastic cell invasion, expansion, and metastasis. CAFs are not present peritumorally as individual cells but they act orchestrated to fully deploy a desmoplastic program, characterized by "syncytial" (or collective) configuration and altered cell adhesion properties. Such myofibroblastic cohorts are reminiscent of those encountered in wound-healing processes. The view of "cancer as a wound that does not heal" led to useful comparisons between wound healing and tumorigenesis and expanded our knowledge of the role of CAF cohorts in cancer. In this integrative model of cancer invasion and metastasis, we propose that the CAF-supported microenvironment has a dual tumor-promoting role. Not only does it provide essential signals for cancer cell dedifferentiation, proliferation, and survival but it also facilitates cancer cell local invasion and metastatic phenomena.

Tumor 'budding', loosely defined by the presence of individual cells and small clusters of tumor cells at the invasive front of carcinomas, has received much recent attention, particularly in the setting of colorectal carcinoma. It has been postulated to represent an epithelial-mesenchymal transition. Tumor budding is a well-established independent adverse prognostic factor in colorectal carcinoma that may allow for stratification of patients into risk categories more meaningful than those defined by TNM staging, and also potentially guide treatment decisions, especially in T1 and T3 N0 (Stage II, Dukes' B) colorectal carcinoma. Unfortunately, its universal acceptance as a reportable factor has been held back by a lack of definitional uniformity with respect to both qualitative and quantitative aspects of tumor budding. The purpose of this review is fourfold: (1) to describe the morphology of tumor budding and its relationship to other potentially important features of the invasive front; (2) to summarize current knowledge regarding the prognostic significance and potential clinical implications of this histomorphological feature; (3) to highlight the challenges posed by a lack of data to allow standardization with respect to the qualitative and quantitative criteria used to define budding; and (4) to present a practical approach to the assessment of tumor budding in everyday practice.

Combinations of the direct renin inhibitor aliskiren with angiotensin receptor blockers (ARBs) or diuretics are effective therapeutic regimens for the treatment of hypertension. A large database of safety information has become available during the past several years with aliskiren in combination trials. Data were pooled from 9 short-term (8-week) and 4 longer-term (26- to 52-week) randomized controlled trials of aliskiren in patients with hypertension. Adverse event (AE) rates were assessed for aliskiren combination therapy compared with component monotherapies. In short-term studies, overall AE rates were similar for patients receiving aliskiren/valsartan or aliskiren/diuretic combinations (32.2%-39.8%) and those receiving the component monotherapies (30.0%-39.6%). In longer-term studies, AE rates with aliskiren/losartan (55.5%) and aliskiren/diuretic (45.0%) combination therapy were similar to those with losartan (53.9%) and diuretic (48.9%) alone. Angioedema and hyperkalemia occurred in similar proportions of patients taking combination therapies vs monotherapy. The safety and tolerability profile of aliskiren in combination with the ARBs valsartan or losartan, or diuretic, is similar to aliskiren, ARBs, or diuretics alone., (© 2011 Wiley Periodicals, Inc.)

While the safety of renin-angiotensin system (RAS)-blocking drugs such as angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers is well known, less is known about the new direct renin inhibitor aliskiren. The authors pooled data from 12 randomized controlled trials of aliskiren in patients with hypertension and analyzed the incidence and types of adverse events (AEs) and laboratory abnormalities. Studies were characterized as short-term (≤2 months) placebo-controlled or long-term (>2 months) active-controlled. Relative risks for AEs of particular interest for RAS blockers were calculated. In short-term studies, AEs occurred in similar proportions of aliskiren 150 mg and 300 mg (33.6% and 31.6%, respectively) and placebo treatment groups (36.8%). In long-term studies, a lower proportion of patients treated with aliskiren 150 mg and 300 mg had AEs (33.7% and 43.2%, respectively) than those treated with ACE inhibitors (60.1%), angiotensin receptor blockers (53.9%), and thiazide diuretics (48.9%). Events of special interest, including angioedema, hyperkalemia, and diarrhea occurred in similar proportions of patients taking aliskiren, placebo, and comparator agents. In studies of up to 36 weeks, patients treated with aliskiren were significantly less likely to develop cough than those treated with ACE inhibitors. At the registered doses of 150 mg and 300 mg daily, aliskiren has safety and tolerability profiles similar to placebo, other RAS blockers, and diuretics. Cough rates are lower with aliskiren compared with ACE inhibitors., (© 2010 Wiley Periodicals, Inc.)

Systemic mastocytosis is an uncommon condition characterized by abnormal proliferation of mast cells in one or more organ. The specific D816V KIT mutation is present in most cases. Gastrointestinal symptoms occur commonly but histologic characterization of gastrointestinal involvement is incomplete. The purpose of this study was (1) to describe the clinicopathologic features in five patients with systemic mastocytosis involving the gastrointestinal tract and (2) to determine whether gastrointestinal involvement is associated with the usual D816V mutation or a different mutation. Clinical details were obtained from the hospital of origin or referring pathologist. Histologic features were documented in slides stained with hematoxylin and eosin, mast cell tryptase and CD117. Molecular analysis for the D816V KIT mutation was performed on formalin-fixed paraffin-embedded sections. Symptoms included diarrhea/loose stools (n=5), abdominal pain (n=4), vomiting (n=3) and weight loss (n=3). Other findings included cutaneous lesions of mastocytosis (n=4), malabsorption (n=2), hypoalbuminemia (n=2) and constitutional growth delay (n=1). Sites of gastrointestinal involvement included the colon (n=5), duodenum (n=3) and terminal ileum (n=3). Endoscopic/gross findings included mucosal nodularity (n=4), erosions (n=2) and loss of mucosal folds (n=2). In three patients the endoscopic appearance was considered consistent with inflammatory bowel disease. All cases showed increased mast cell infiltration of the lamina propria, confirmed by immunohistochemistry for mast cell tryptase and CD117. In two cases, mast cells had abundant clear cytoplasmic resembling histiocytes. Marked eosinophil infiltrates were present in four patients, in one patient leading to confusion with eosinophilic colitis. Architectural distortion was noted in three cases. The D816V KIT mutation was present in all four cases tested. In conclusion, gastrointestinal involvement by systemic mastocytosis is characterized by a spectrum of morphologic features that can be mistaken for inflammatory bowel disease, eosinophilic colitis or histiocytic infiltrates. Systemic mastocytosis involving the gastrointestinal tract is associated with the usual D816V KIT mutation.

Irritable bowel syndrome is a common disorder defined by a symptom complex including abdominal pain and altered bowel habit. The etiopathogenesis appears to be multifactorial and to involve altered gastrointestinal motor function, enhanced perception of visceral stimuli and psychosocial factors. More recently a role for mucosal immune activation has been suggested. Routine histologic examination reveals no mucosal abnormality in the majority of cases but quantitative histological, immunohistochemical and ultrastructural analyses reveal subtle morphologic changes involving lymphocytes, mast cells, enterochromaffin cells and enteric nerves. The recent appreciation of these changes has led to new hypotheses linking central and enteric nervous systems to immune processes. This review highlights the spectrum of morphologic changes that occur in irritable bowel syndrome, examines their relationship to the pathophysiology of irritable bowel syndrome and considers their relevance to daily pathology practice.

The discovery of a series of genetic and serological markers associated with disease susceptibility and phenotype in inflammatory bowel disease has led to the prospect of an integrated classification system involving clinical, serological and genetic parameters. The Working Party has reviewed current clinical classification systems in Crohn's disease, ulcerative colitis and indeterminate colitis, and provided recommendations for clinical classification in practice. Progress with respect to integrating serological and genetic markers has been examined in detail, and the implications are discussed. While an integrated system is not proposed for clinical use at present, the introduction of a widely acceptable clinical subclassification is strongly advocated, which would allow detailed correlations among serotype, genotype and clinical phenotype to be examined and confirmed in independent cohorts of patients and, thereby, provide a vital foundation for future work.

Benign apocrine lesions have been described in the anogenital region, although according to the World Health Organisation convincing examples of anal apocrine adenocarcinomas have not been published. This report describes the case of an invasive apocrine adenocarcinoma arising in a benign adenoma in the perianal region of a 45 year old woman. The origin and invasiveness are supported by histological and immunohistochemical studies.

Indeterminate colitis (IC) originally referred to those 10-15% of cases of inflammatory bowel disease (IBD) in which there was difficulty distinguishing between ulcerative colitis (UC) and Crohn's disease (CD) in the colectomy specimen. However, IC is increasingly used when a definitive diagnosis of UC or CD cannot be made at colonoscopy, in colonic biopsies or at colectomy. The diagnostic difficulties may explain the variably reported prevalence of IC. Clinically, most patients with IC evolve to a definite diagnosis of UC or CD on follow up. The role of ancillary tests in the distinction of UC from CD is reviewed. The low sensitivity of serological markers limits their usefulness. Other tests include upper endoscopy and magnetic resonance imaging. The definition of IC may not be a purely histological one derived from resected specimens, but rather a clinicopathological one. This review offers some personal observations and viewpoints, and proposes an approach to some of the relatively more esoteric combinations of findings.

Purpose: Cadherins and associated catenins are important mediators of epithelial cell-cell adhesion, as well as the Wnt-signaling pathway. Significant changes in their expression or structure have been implicated in malignancy. This study aimed to investigate the epithelial-cadherin (E-cadherin) and beta-catenin expression changes during multistage, pancreatic ductal carcinogenesis., Experimental Design: Ninety-four Whipple resection specimens were retrieved from the surgical pathology files of the University Health Network (Toronto, Canada), from which tissue microarray blocks containing 36 pancreatic ductal adenocarcinomas, 34 PanIN-1A lesions, 28 PanIN-1B lesions, 27 PanIN-2 lesions, 16 PanIN-3 lesions, and 32 normal ducts were constructed. The E-cadherin, beta-catenin, and the phosphorylated glycogen synthase kinase-3beta of the Wnt/beta-catenin pathway were immunohistochemically evaluated in these duct/PanIN lesions., Results: There was marked increase in the cytoplasmic E-cadherin expression in PanIN lesions (P < 0.0001) and adenocarcinoma (P = 0.005) compared with normal pancreatic ducts. In contrast, reduced/loss of E-cadherin membranous expression was also significant in ductal adenocarcinoma compared with both the PanIN lesions (P < 0.0001) and normal ducts (P = 0.05). The beta-catenin expression showed significantly more frequent aberrant nuclear localization in high-grade PanIN lesions, particularly PanIN2 and in adenocarcinoma compared with normal ducts or low grade PanIN lesions (P < 0.0001). However, there was a lack of correlation between phospho(Ser9)-glycogen synthase kinase-3beta cytoplasmic expression and beta-catenin aberrant nuclear expression (P = 0.07)., Conclusions: Aberration in the expression of E-cadherin and its associated beta-catenin is evident in pre-invasive (PanIN) neoplastic pancreatic duct cells, suggesting involvement of pathways leading to beta-catenin stabilization during pancreatic duct cell carcinogenesis.

Heterozygous germline DNA mismatch repair gene mutations are typically associated with hereditary nonpolyposis colorectal cancer. The molecular hallmark of this syndrome is high-frequency microsatellite instability in the tumors. Rare childhood cases with homozygous or compound heterozygous DNA mismatch repair gene mutations have a described predisposition to leukemia, lymphoma, and brain tumors but not to gastrointestinal cancer. We have now characterized a family in which 2 children with a homozygous germline DNA mismatch repair gene mutation developed early-onset gastrointestinal cancers. The 11-year-old proband had café-au-lait macules and developed metastatic duodenal adenocarcinoma that arose in a tubulovillous adenoma. His 9-year-old sister with café-au-lait macules and axillary freckling presented with malignant colon polyps. A 6-year-old sister with café-au-lait macules, hairy nevi, and a plexiform neurofibroma of the tongue has no malignancies to date. The family history did not fulfill the Amsterdam criteria for hereditary nonpolyposis colorectal cancer, but 2 relatives in their 60s had gastric cancer and colorectal cancer, whereas the parents, who are first cousins, remain cancer free. The proband's metastatic duodenal cancer and his sister's malignant colon polyps had high-frequency microsatellite instability but had detectable MLH1, MSH2, and MSH6 proteins by immunohistochemistry. Because some germline DNA mismatch repair gene deficiencies are associated with apparently intact immunohistochemical DNA mismatch repair gene expression in tumors, we proceeded to DNA sequencing, which showed that all 3 children had a germline homozygous MLH1 missense mutation (exon 18, codon 687, CGG-->TGG), whereas both parents were heterozygous for this mutation.

The inflammatory bowel diseases are considered an abnormal host immune response to an environmental stimulus. Evidence suggests a role for intestinal bacteria in initiating and/or providing an ongoing stimulus for inflammation in inflammatory bowel disease. Helicobacter pylori is the major cause of active chronic gastritis and peptic ulcers in humans and has been linked to gastric carcinoma and lymphoma. Studies in various animal models, particularly mice, have identified enterohepatic Helicobacter species that are capable of causing hepatitis and enterocolitis. We hypothesize that Helicobacter species may have a role in maintaining inflammation in humans with inflammatory bowel disease. In order to investigate this, biopsy specimens were obtained from patients with and without inflammatory bowel disease. DNA was extracted from the tissues and subjected to PCR with primers designed to detect the ribosomal DNA of members of the Helicobacter species. DNA from six biopsy samples from 60 inflammatory bowel disease patients tested positive. This included 5 of 33 ulcerative colitis patients that were positive compared to 0 of 29 age-matched controls (P < 0.04). Sequencing of the bands produced by PCR amplification revealed >or=99% homology with H. pylori. These results indicate that a member of the Helicobacter species may be involved in some cases of ulcerative colitis.

Long segment Barrett's esophagus (LSBE) is a recognized risk factor for the development of esophageal dysplasia and carcinoma. However, the risk of dysplasia arising within intestinal metaplasia below a normal-appearing Z-line (i.e., in native cardiac mucosa) is unknown. Regular endoscopic surveillance is required in patients with LSBE and is frequently performed in short segment BE (SSBE), but the need for surveillance in cardiac intestinal metaplasia (CIM) is unknown. Unfortunately IM arising in SSBE and immediately below a normal Z-line can be indistinguishable histologically on H&E stains. Previous reports suggest that the appearance of superficial CK20 immunohistochemical staining accompanied by intermediate and deep CK7 positivity is characteristic of BE, whereas CIM specimens show superficial and deep CK20 positivity and weak to absent CK7 staining. We hypothesized that CK7/20 immunostaining of metaplastic biopsies from the esophagus and stomach would allow complete differentiation of these two entities when correlated with the endoscopic appearance. We undertook an evaluation of gastric and esophageal specimens to determine whether these characteristics were valid. Cases of both BE (long and short segment) and CIM, as well as cases of gastric cardiac biopsies lacking IM, were evaluated for CK7 and CK20 and correlated with the endoscopic appearance. We observed that, although the "Barrett's" pattern of CK7/20 was maintained for many cases of BE, the sensitivity and specificity were only moderate (65% and 56%, respectively). The pattern of staining for the CIM was variable, i.e., some cases showed a CK7/20 Barrett's pattern despite a normal appearance at endoscopy. The differences between this and previous studies may be due to inaccurate visualization of SSBE on endoscopy, the development of very early SSBE cases, inter-observer variability, fixation differences, or antibody differences. Whatever the cause of the differences, if results between laboratories are not comparable, CK7/20 immunostaining cannot be used to differentiate reliably between IM present in biopsy specimens taken from above versus below the Z-line. However, further studies should be performed to determine whether the presence or absence of a Barrett's pattern of CK7/20 immunostaining could predict progression to dysplasia or carcinoma.

Smooth muscle lesions of the large bowel, excluding the rectum, are generally rare, and diffuse smooth muscle lesions, termed leiomyomatosis, are even rarer. In this report, we document, for the first time, leiomyomatosis-like lymphangioleiomyomatosis (LAM) of the ascending, transverse, and descending colon in association with bilateral renal angiomyolipoma (AML) in a 30-year-old Chinese female with tuberous sclerosis complex (TSC). She presented with protracted constipation for which a colectomy was performed. Histology disclosed multiple confluent nodular CD34 and CD117 negative smooth muscle proliferation within the large bowel wall, whereas the renal biopsy revealed typical features of AML. Interestingly, the epithelioid smooth muscle cells of both the colonic and renal lesions were HMB45 positive, suggesting that leiomyomatosis-like LAM of the colon, pulmonary LAM and AML are closely related entities. The patient remained free of complications for the last five years after surgery. Leiomyomatosis-like LAM of the large bowel probably represents another manifestation of the tendency of TSC to be associated with proliferative lesions.

The relationship between the development of the enteric nervous system and interstitial cells of Cajal (ICC) in the human small intestine was investigated in a full-term infant who presented with intestinal pseudo-obstruction. Immunohistochemistry revealed absence of enteric nerves and ganglia but abundant c-Kit immunoreactivity associated with Auerbach's plexus (ICC-AP). However, c-Kit immunoreactivity associated with the deep muscular plexus (ICC-DMP) and intermuscular ICC was absent. Electron microscopy showed ICC-AP with a normal ultrastructure; ICC-DMP were seen but were severely injured, suggesting degeneration. In vitro recording of intestinal muscle showed slow wave activity as well as response to cholinergic stimulation. Fluoroscopic examination of the small bowel showed a variety of motor patterns, including rhythmic, propagating contractions. In conclusion, total absence of enteric nerves was associated with absence of normal ICC-DMP. However, a normal musculature, including a network of ICC-AP, allowed for generation of rhythmic, propagating contractile activity, suggesting the presence of functional motor activity.

Background: Patients with duodenal ulcer (DU) have an increased parietal cell mass and sensitivity to secretagogues, with increased acid output., Aim: To determine the effect of Helicobacter pylori eradication on parietal cell sensitivity and gastric acid secretion., Subjects and Methods: Twenty-five H pylori-positive DU patients and 18 H pylori-negative healthy volunteers were studied. Serum H pylori immunoglobulin G, basal acid output and acid secretory response to graded doses of pentagastrin were determined before and after treatment, at six months and at one year. Subjects were randomly assigned to ranitidine or sucralfate treatment for six weeks, and all DU patients received bismuth subsalicylate, metronidazole and tetracycline for the first two weeks., Results: H pylori was eradicated in 66% of patients receiving sucralfate and 92% receiving ranitidine. Compared with healthy volunteers, DU patients demonstrated a 2.7-fold greater basal acid output, a 1.3-fold greater peak acid output, significantly higher acid output for each dose of pentagastrin and a 1.38-fold increase in the area under the pentagastrin dose acid response curve. Cure of H pylori, irrespective of ulcer healing regimen, resulted in a gradual decrease in acid secretory capacity with basal acid output, peak acid output and area under the pentagastrin dose acid response curve returning to healthy volunteer levels by one year. No demonstrable differences were observed in parietal cell sensitivity in all subjects before or after treatment. These data suggest that disturbances in acid secretion in H pylori-positive DU patients are not due to an increased parietal cell sensitivity to pentagastrin but rather due to an increased parietal cell mass with increased capacity to secrete acid, which gradually resolves following cure.

Background: Use of the conventional Western and Japanese classification systems of gastrointestinal epithelial neoplasia results in large differences among pathologists in the diagnosis of oesophageal, gastric, and colorectal neoplastic lesions., Aim: To develop common worldwide terminology for gastrointestinal epithelial neoplasia., Methods: Thirty one pathologists from 12 countries reviewed 35 gastric, 20 colorectal, and 21 oesophageal biopsy and resection specimens. The extent of diagnostic agreement between those with Western and Japanese viewpoints was assessed by kappa statistics. The pathologists met in Vienna to discuss the results and to develop a new consensus terminology., Results: The large differences between the conventional Western and Japanese diagnoses were confirmed (percentage of specimens for which there was agreement and kappa values: 37% and 0.16 for gastric; 45% and 0.27 for colorectal; and 14% and 0.01 for oesophageal lesions). There was much better agreement among pathologists (71% and 0.55 for gastric; 65% and 0.47 for colorectal; and 62% and 0.31 for oesophageal lesions) when the original assessments of the specimens were regrouped into the categories of the proposed Vienna classification of gastrointestinal epithelial neoplasia: (1) negative for neoplasia/dysplasia, (2) indefinite for neoplasia/dysplasia, (3) non-invasive low grade neoplasia (low grade adenoma/dysplasia), (4) non-invasive high grade neoplasia (high grade adenoma/dysplasia, non-invasive carcinoma and suspicion of invasive carcinoma), and (5) invasive neoplasia (intramucosal carcinoma, submucosal carcinoma or beyond)., Conclusion: The differences between Western and Japanese pathologists in the diagnostic classification of gastrointestinal epithelial neoplastic lesions can be resolved largely by adopting the proposed terminology, which is based on cytological and architectural severity and invasion status.

Most gastrointestinal stromal tumors (GISTs), a subgroup of mesenchymal neoplasms of the gut wall, express both Kit (CD117) and CD34 proteins. It has been suggested that GISTs originate from or differentiate into interstitial cells of Cajal (ICC), after several reports indicated that ICC are likely the only cells in the gut which express both Kit and CD34. ICC are among the few cell types resident in the gut which express Kit, together with mast cells. However, the question whether or not ICC express CD34 is currently disputed. Using single-cell reverse transcriptase-polymerase chain reaction (RT-PCR) on cultured murine intestinal cells, single ICC were selected by morphology and tested for the expression of c-kit and CD34 mRNA. Most ICC were only c-kit-positive, however a subset (7 out of 43) were double positive for both c-kit and CD34. In the human small intestine, sequential immunohistochemical staining for Kit and CD34 proteins on the same 3-microm sections showed that some of the ICC surrounding Auerbach's plexus and ICC within the circular muscle layer of the small intestine were positive for both Kit and CD34. In addition, CD34(+)Kit(-) cells were seen adjacent to ICC. These data from two different techniques indicate that ICC can be double positive for Kit and CD34. Thus, GISTs with the Kit(+)CD34(+) phenotype may arise from a subpopulation of CD34(+) Kit(+) ICC.

In the pediatric population, the associations of Helicobacter pylori with gastritis, gastric ulcer, duodenitis and duodenal ulcer, and with duodenal gastric surface metaplasia and disorders of the D cell- G cell axis resulting in hypergastrinemia, are well established and in many ways resemble their counterparts in adults. Eradication of H pylori invariably results in the reversal of these diseases with time. There are also suggestions that gastric surface metaplasia is more extensive in children with H pylori, and may be the site of duodenal H pylori infection and associated duodenal erosions or ulcers. There is no consensus as to whether H pylori in children is more or less severe than in adults. In one pediatric cohort, H pylori was associated with increased intensity of inflammation, while other studies suggest that acute inflammation may be less intense in children overall but that chronic inflammation may be increased in intensity, including lymphoid hyperplasia, which in turn may correlate with endoscopic nodularity. Lymphoid hyperplasia and nodular gastritis appear to be more frequent in children than in adults and usually regress following H pylori eradication. However, in children, other diseases or morphological abnormalities, including some loss of glands (atrophy), occasionally intestinal metaplasia, lymphoproliferative diseases including low grade mucosal-associated lymphoid tissue lymphoma, lymphocytic gastritis and hypertrophic gastritis/Menetrier's disease, are much less frequently associated with H pylori than in adults. Other associations are rarely seen in children, primarily because the time required for these to develop takes the individual to adulthood; for example, while intestinal metaplasia occurs in the pediatric population, the complications of adenoma/dysplasia and carcinoma are rare. In adults, inflammatory and hyperplastic polyps, atrophic gastritis and pernicious anemia, and in some patients granulomas (granulomatous gastritis), may also be associated with H pylori infection. Greater awareness of the spectrum of diseases associated with H pylori may well lead to their increased recognition in the pediatric population. Some diseases, particularly Crohn's disease, but also human immunodeficiency virus infection, have a negative association with H pylori that appears not to be simply a result of the excess antibiotic therapy that these patients receive. These variations in association and reactions to H pylori, some of which are age-related, may allow the different host responses to H pylori that occur in humans to be examined.

It has become increasingly apparent that the Japanese and Western systems of classifying dysplasia and carcinoma in the gastrointestinal tract are not the same. The implication of these differences is that in an article in a Western journal on gastrointestinal 'cancer' originating from Japan, it is often impossible to repeat the study to confirm or refute it because of these differences in definitions. 'Carcinoma' is diagnosed in Japan by virtue of its structural and cytological features but by invasion in the Western system. Adenoma does not mean a dysplastic lump in the Japanese system (although it can), but in most cases is similar to low grade dysplasia irrespective of the macroscopic and/or endoscopic appearances (hence flat and depressed adenomas in the Japanese system); however, most examples of high grade dysplasia in the Western system, as well as some low grade dysplasia, are 'cancer' in the Japanese system. Conversely, both have conceptual areas that are useful in the other's system.

Helicobacter pylori infection is an important cause of peptic ulcer disease and chronic gastritis. Infection with this bacterium stimulates the production of immunoglobulin (Ig) G antibody. Salivary IgG antibody tests to detect H pylori infection offer a convenient and noninvasive method of diagnosis. To evaluate an IgG salivary antibody kit, saliva was collected from 157 out-patients with dyspepsia referred for endoscopy to a tertiary centre. A salivary IgG ELISA antibody assay was performed using the Helisal Helicobacter pylori (IgG) assay kit, and at least four gastric biopsies were obtained. H pylori infection was confirmed by demonstration of the organism on Warthin-Starry silver stain (sensitivity 85%, specificity 55%). The prevalence of infection with H pylori was 30%. When the analysis was redone, excluding those treated with eradication therapy, the results were similar (sensitivity 86%, specificity 58%). The positive predictive value of the assay was 45% and the negative predictive value was 90%. Despite the ease of sampling, the assay used has limited diagnostic utility, lacking the predictive value to indicate which patients referred with dyspeptic symptoms to a tertiary care setting are infected with H pylori.

Background: Studies in animals indicate that inflammation causes changes in smooth muscle contractility. Because Crohn's disease is associated with altered motility, this study investigated the contractility of intestinal muscle resected from patients with or without Crohn's disease., Methods: The isometric contraction of muscle strips from the small bowel of 36 patients with and 24 patients without Crohn's disease was examined., Results: In longitudinal muscle from patients with Crohn's disease, there was a 55% increase in maximum contraction induced by carbachol but not histamine, but there was no change in the 50% effective dose (ED50) for these agonists. In contrast, in circular muscle from patients with Crohn's disease there was a sevenfold decrease in the ED50 value for carbachol but no change in maximum contraction. There was a 2.5-fold increase in the maximum response to histamine, but no change in ED50, in circular muscle from patients with Crohn's disease. However, there was no change in KCl-induced contraction between the two groups. The carbachol responses were atropine sensitive. Histamine responses were blocked by the H1 antagonist mepyramine but were not altered by a diamine oxidase inhibitor. All responses were tetrodotoxin insensitive., Conclusion: These results show altered receptor-mediated contraction in small intestinal muscle in patients with Crohn's disease.

The use of oral non-steroidal anti-inflammatory drugs (NSAIDs) in 31 patients with collagenous colitis and in 31 matched control patients with irritable bowel syndrome or colonic diverticular disease who had also undergone colonoscopy and biopsy was investigated. The long term use (greater than 6 months) of NSAIDs was significantly commoner in the study group (19/31) than in the control group (4/31) (p less than 0.02), even assuming the most adverse drug history in six patients in whom this could not be established. In all patients with collagenous colitis taking NSAIDs, diarrhoea followed the use of these drugs, and by a mean (SD) of 5.5 (4.4) years (range 0.5 to 15 years). In three patients with collagenous colitis, diarrhoea improved after withdrawing NSAIDs; rechallenge in one was followed by a recurrence of diarrhoea, which improved after withdrawing the drug again. It is suggested that NSAIDs may play an aetiological role in the diarrhoea and thickened collagen band in some patients with collagenous colitis.

We investigated the distribution of the collagen band in 33 patients with collagenous colitis to estimate the likelihood of the disease being diagnosed in biopsy specimens from the left side of the colon, such as those obtained using flexible sigmoidoscopy. To be included in this study patients had a subepithelial collagen band greater than or equal to 10 microns, an increase in chronic inflammatory cells in the same specimen, and diarrhoea for which there was no other apparent cause. In 17 patients undergoing full colonoscopy with a thickened collagen band, collagenous colitis was frequently patchy, even though overall the thickened collagen band was almost equally distributed throughout the colon. Rectal biopsy specimens showed a normal collagen band in 73% of patients, while a thickened collagen band was found in 82% of patients in at least one specimen from the left side of the colon. Three patients had a thickened collagen band only in the caecum. In three of eight rectal biopsy specimens with a normal collagen band there was no mucosal inflammation to raise the possibility of proximal disease, although all but one specimen with a normal collagen band from the sigmoid and descending colon were inflamed. Rectal biopsy alone is therefore a relatively poor method of making the diagnosis. Flexible sigmoidoscopy with multiple biopsy specimens from several sites is a reasonable initial investigation but not sufficient to exclude collagenous colitis when based on the presence of a thickened collagen band alone. Should left sided biopsy specimens show a normal collagen band but an inflamed mucosa, total colonoscopy with multiple specimens including the caecum may be required to establish the diagnosis.

In chronic ulcerative colitis, the object of surveillance is prevention of cancer or at least prevention of death from cancer by diagnosis at an early curable stage or by detection at a pre-malignant phase. Patients must be informed about their cancer risk as well as the limitations of endoscopic surveillance and the availability of surgical alternatives. Physicians must bear in mind the risks, benefits and costs of surveillance procedures. Patients at greatest risk of cancer for whom endoscopic surveillance is warranted are those with extensive colitis of greater than 8 years duration. Colonoscopy should be performed every 1 to 2 years at which time multiple biopsies are obtained from every 10-12 cm of normal-appearing mucosa. Targeted biopsies should also be obtained from areas where the surface appears raised as a broad-based polyp, low irregular plaque or villiform elevation, or from an unusual ulcer, particularly one with raised edges, or from a stricture. Typical inflammatory polyps need not be sampled. Colectomy is recommended in the presence of multifocal high-grade dysplasia if confirmed by an experienced pathologist. The identification of a mass lesion associated with any degree of overlying dysplasia is also a generally accepted indication for colectomy, while persistent low-grade dysplasia without a mass is somewhat more controversial. Recently introduced biomarkers may replace or supplement dysplasia in surveillance programmes as well as provide new information about malignant transformation.

In performing colonoscopy over a 4-yr period on 112 patients with long-standing ulcerative colitis, a dysplasia-associated lesion or mass (DALM) was found in 12. This appeared as either a single polypoid mass (5 cases), a plaquelike lesion (2 cases), or multiple polyps (5 cases). In 7 of these 12 cases carcinoma was subsequently found. This was particularly true in the 5 cases of single polypoid masses where all 5 contained invasive carcinoma. In none of the cases associated with malignancy did multiple biopsies of the DALM reveal invasive carcinoma. In only 2 of the 7 patients with carcinoma was the dysplasia "severe," being "mild" or "moderate" in the remaining 5. In the 27 patients with dysplasia found incidentally in random biopsies of flat mucosa only one carcinoma was found, in contrast to the 7 cancers in 12 patients with DALM. This difference leads us to regard the finding of DALM, especially a single polypoid mass, as highly significant in patients with long-standing ulcerative colitis. It carries a sufficiently high risk of cancer, thereby constituting a strong indication for colectomy.