Adenomatous and foveolar gastric dysplasia: distinct patterns of mucin expression and background intestinal metaplasia. Am J Surg Pathol. 2008;32:524-533. [PMID: 18300795 DOI: 10.1097/pas.0b013e31815b890e]

Mucin phenotype and microvessels in early gastic cancer: Magnifying endoscopy with narrow band imaging

Backgrounds

In order to detect early gastric cancer (EGC), this research sought to assess the diagnostic utility of magnifying endoscopy (ME) as well as the significance of mucin phenotype and microvessel features.

Methods

402 individuals with an EGC diagnosis underwent endoscopic submucosal dissection (ESD) at the Department of ME between 2012 and 2020. After adjusting for image distortion, high-magnification endoscopic pictures were taken and examined to find microvessels in the area of interest. The microvessel density was measured as counts per square millimeter (counts/mm2) after segmentation, and the vascular bed's size was computed as a percentage of the area of interest. To identify certain properties of the microvessels, such as end-points, crossing points, branching sites, and connection points, further processing was done using skeletonized pixels.

Results

According to the research, undifferentiated tumors often lacked the MS pattern and showed an oval and tubular microsurface (MS) pattern, but differentiated EGC tumors usually lacked the MS pattern and presented a corkscrew MV pattern. Submucosal invasion was shown to be more strongly associated with the destructive MS pattern in differentiated tumors as opposed to undifferentiated tumors. While lesions with a corkscrew MV pattern and an antrum or body MS pattern revealed greater MUC5AC expression, lesions with a loop MV pattern indicated higher MUC2 expression. Furthermore, CD10 expression was higher in lesions with a papillary pattern and an antrum or body MS pattern.

Conclusion

These results imply that evaluating mucin phenotype and microvessel features in conjunction with magnifying endoscopy (ME) may be a useful diagnostic strategy for early gastric cancer (EGC) detection. Nevertheless, further investigation is required to confirm these findings and identify the best course of action for EGC diagnosis.

Pathology and Clinical Relevance of Gastric Epithelial Dysplasia

Gastric dysplasia is defined as an unequivocally neoplastic epithelium. Dysplastic lesions are characterized by cellular atypia reflective of abnormal differentiation and disorganized glandular architecture. The last few years have been marked by a refinement of the prognosis and risk of progression of gastric dysplasia and the recognition of novel morphologic patterns of dysplasia. Determination of the correct diagnosis and grade of dysplasia are critical steps since it will be predicting the risk of malignant transformation and help tailor appropriate surveillance strategy. This review describes the morphologic characteristics of conventional dysplasia and nonconventional gastric dysplasia that have been more recently characterized.

Prediction of the invasion depth of superficial nonampullary duodenal adenocarcinoma

OBJECTIVES

Distinguishing between intramucosal cancer and submucosal invasive cancer is vital for optimal treatment selection for patients with superficial nonampullary duodenal adenocarcinoma (SNADAC); however, standard diagnostic systems for diagnosing invasion depth are as yet undetermined.

METHODS

Of 205 patients with SNADAC who underwent treatment at our institution between 2006 and 2022, 188 had intramucosal cancer and 17 had submucosal invasive cancer. The clinical, endoscopic, and pathological features used in the preoperative diagnosis of invasion depth and the diagnostic performance of endoscopic ultrasonography (EUS) were retrospectively analyzed in 85 patients.

RESULTS

The oral side of the papilla tumor location, protruded or mixed macroscopic type, and moderately-to-poorly differentiated adenocarcinoma based on biopsy specimens were significantly more frequent in submucosal invasive cancer than in intramucosal cancer (88% vs. 48%; 94% vs. 42%; 47% vs. 0%, respectively). From the relationship between the endoscopic features and the submucosal invasive cancer incidence, submucosal invasion risk was stratified as: (i) low-risk (risk, 2%), all lesions located on the anal side of the papilla and superficial macroscopic type on the oral side of the papilla; and (ii) high-risk (risk, 23%), protruded or mixed macroscopic type on the oral side of the papilla. Based on the biopsy specimens, all eight patients with moderately-to-poorly differentiated adenocarcinoma had submucosal invasive cancer. Furthermore, EUS was not associated with invasion depth's diagnostic accuracy improvements.

CONCLUSION

Optimal treatment indications for SNADAC can be selected based on the risk factors of submucosal invasion by tumor location, macroscopic type, and biopsy diagnosis.

Colorectal dysplasia in chronic inflammatory bowel disease: a contemporary consensus classification and interobserver study

The clinical management of patients with dysplasia in chronic inflammatory bowel disease (IBD) is currently guided by Riddell et al.'s grading system (negative, indefinite, low grade, high grade) from 1983 which was based primarily on nuclear cytoarchitectural characteristics. Although most dysplasia in IBD resembles sporadic adenomas morphologically, other distinctive potential cancer precursors in IBD have been described over time. Recognizing the need for a updated comprehensive classification for IBD-associated dysplasia, an international working group of pathologists with extensive clinical and research experience in IBD devised a new classification system and assessed its reproducibility by having each participant assess test cases selected randomly from a repository of electronic images of potential cancer precursor lesions. The new classification system now encompasses three broad categories and nine sub-categories: 1) intestinal dysplasia (tubular/villous adenoma-like, goblet cell deficient, crypt cell, traditional serrated adenoma-like, sessile serrated lesion-like and serrated NOS), 2) gastric dysplasia (tubular/villous and serrated), and 3) mixed intestinal-gastric dysplasia. In the interobserver analysis, 67% of the diagnoses were considered definitive and achieved substantial inter-rater agreement. The key distinctions between intestinal and gastric lesions and between serrated and non-serrated lesions achieved substantial and moderate inter-rater agreement overall, respectively, however, the distinctions among certain serrated sub-categories achieved only fair agreement. Based on the Riddell grading system, definite dysplasia accounted for 86% of the collective responses (75% low grade, 11% high grade). Based on these results, this new classification of dysplasia in IBD can provide a sound foundation for future clinical and basic IBD research.

A Standardized Pathology Report for Gastric Cancer: 2nd Edition

The first edition of 'A Standardized Pathology Report for Gastric Cancer' was initiated by the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists and published 17 years ago. Since then, significant advances have been made in the pathologic diagnosis, molecular genetics, and management of gastric cancer (GC). To reflect those changes, a committee for publishing a second edition of the report was formed within the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists. This second edition consists of two parts: standard data elements and conditional data elements. The standard data elements contain the basic pathologic findings and items necessary to predict the prognosis of GC patients, and they are adequate for routine surgical pathology service. Other diagnostic and prognostic factors relevant to adjuvant therapy, including molecular biomarkers, are classified as conditional data elements to allow each pathologist to selectively choose items appropriate to the environment in their institution. We trust that the standardized pathology report will be helpful for GC diagnosis and facilitate large-scale multidisciplinary collaborative studies.

Sporadic and Familial Adenomatous Polyposis-associated Foveolar-type Adenoma of the Stomach

Gastric foveolar-type adenoma (FA) is a rare benign neoplasm occurring either sporadically or in patients with familial adenomatous polyposis (FAP). However, the molecular features of FA and the relationship between sporadic and syndromic lesions remain unclear. In this study, we performed clinicopathological, immunohistochemical, and genetic analyses of 18 sporadic and 30 FAP-associated FAs. Most sporadic and FAP-associated FAs were located in the upper or middle third of the stomach, on a background of fundic gland mucosa. Most lesions were low-grade, but 3 lesions had a high-grade component. Sporadic FAs included 2 morphologically distinct subtypes, that is, flat and raspberry-like FAs, which we distinguished based on the endoscopic features. Seven lesions were regarded as flat FAs, appearing as large, slightly elevated lesions and measuring 11 to 87 mm in size. Conversely, 10 raspberry-like FAs were small bright-red polyps, measuring 2 to 8 mm in size. FAP-associated FAs, particularly larger lesions, exhibited morphologic features resembling flat FAs but varied significantly in size (2 to 103 mm). Mutation analysis identified APC and KRAS mutations in all flat FAs but never in raspberry-like FAs. Remarkably, somatic APC and KRAS mutations were also detected in 19 (63%) and 27 (90%) of FAP-associated FAs, respectively. This indicates that they are genetically equivalent to sporadic, flat FAs. This study showed that sporadic FA includes at least 2 morphologically and genetically distinct subtypes: flat and raspberry-like FA. Furthermore, flat FA represents a sporadic counterpart of FAP-associated FA.

A standardized pathology report for gastric cancer: 2nd edition

The first edition of 'A Standardized Pathology Report for Gastric Cancer' was initiated by the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists and published 17 years ago. Since then, significant advances have been made in the pathologic diagnosis, molecular genetics, and management of gastric cancer (GC). To reflect those changes, a committee for publishing a second edition of the report was formed within the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists. This second edition consists of two parts: standard data elements and conditional data elements. The standard data elements contain the basic pathologic findings and items necessary to predict the prognosis of GC patients, and they are adequate for routine surgical pathology service. Other diagnostic and prognostic factors relevant to adjuvant therapy, including molecular biomarkers, are classified as conditional data elements to allow each pathologist to selectively choose items appropriate to the environment in their institution. We trust that the standardized pathology report will be helpful for GC diagnosis and facilitate large-scale multidisciplinary collaborative studies.

Sporadic foveolar-type adenoma in gastric body/antrum junction with gastritis cystica profunda

Background

Sporadic gastric foveolar-type adenomas are extremely rare and are usually small, flat or slightly raised lesions that occur in the oxyntic mucosa.

Case presentation

We reported here a case of a 70-year-old female with a sporadic gastric foveolar-type adenoma occurring in the mucosa at the junction of the gastric body/antrum. The adenoma was a protruding lesion of 2 × 1.8 cm sized, causing symptoms of upper gastrointestinal bleeding, and the basal and surrounding mucosa showed pseudopyloric gland metaplasia without atrophy, intestinal metaplasia, H. pylori infection, or active inflammation. It had somatic mutations in both APC and KRAS genes.

Conclusions

This is the first reported case of a large sporadic gastric foveolar-type adenoma that occurred in the mucosa of pseudopyloric gland metaplasia and with Gastritis Cystica Profunda, which modify our understanding of the morphological features and molecular underpinnings of this type of lesion.

Some Morphology Frontiers of Dysplasia in the Tubular Gastrointestinal Tract: The Rodger C. Haggitt Memorial Lecture

This review, based on the content of the 2020 US Gastrointestinal Pathology Society's Rodger Haggitt Lecture, concerns an array of tubular gastrointestinal tract dysplastic or possible "predysplastic lesions" with an almost purely morphologic focus based on our collaborative efforts over the past few years. These processes include esophageal epidermoid metaplasia, Barrett esophagus-associated dysplasia, polypoid gastric dysplastic lesions, small intestinal dysplasia, and the ability of metastases to mimic it, the controversial "serrated epithelial change" encountered in the setting of long-standing ulcerative and Crohn colitis, and recently described anal columnar human papilloma virus-associated neoplasms.

Association between mucin phenotype and lesion border detection using acetic acid-indigo carmine chromoendoscopy in early gastric cancers

BACKGROUND

For successful treatment of early gastric cancers (EGCs), it is crucial to define the horizontal border of the lesion with high accuracy. Acetic acid-indigo carmine (AI) chromoendoscopy has been used to determine the horizontal border in EGCs, but this technique is less potent in certain situations. Mucin phenotype in gastric cancers refers to biological differences in precursor lesions and differences in histopathologic findings, and it might affect AI chromoendoscopy findings. We aimed to investigate the association between mucin phenotype and AI chromoendoscopy findings in EGCs.

METHODS

We prospectively evaluated 126 lesions in 126 patients with endoscopically diagnosed EGCs. Conventional endoscopy and AI chromoendoscopy findings of these lesions before treatment were prospectively analyzed. The border distinction between the lesion and surrounding mucosa was classified as distinct or indistinct on conventional endoscopy and AI chromoendoscopy, respectively. Mucin phenotypes were classified as gastric, intestinal, gastrointestinal, or null type by immunohistochemistry.

RESULTS

The lesion borders were distinct in 46.8% (59/126) of the lesions assessed using conventional endoscopy and in 73.0% (92/126) of those assessed with AI chromoendoscopy (p < 0.001). The border distinction rate of differentiated-type cancers on AI chromoendoscopy was significantly higher than that on conventional endoscopy (66/71 [93.0%] vs. 34/71 [47.9%], p < 0.001), but the border distinction rate of undifferentiated-type cancers on AI chromoendoscopy was not different from that on conventional endoscopy (26/55 [47.3%] vs. 25/55 [45.5%], p = 0.848). Compared with conventional endoscopy, AI chromoendoscopy identified borders in a significantly higher percentage of gastric, intestinal, and gastrointestinal mucin types; however, there was no difference in AI chromoendoscopy findings according to the mucin phenotype (p = 0.271).

CONCLUSION

AI chromoendoscopy was effective in horizontal border delineation in differentiated-type EGCs, but not in undifferentiated-type EGCs. Mucin phenotype had no effect on border distinction using AI chromoendoscopy.

Non-conventional dysplasias of the tubular gut: a review and illustration of their histomorphological spectrum

The increasing use of gastrointestinal endoscopic procedures has led to the recognition by histopathologists of non-conventional (or special-type) dysplasias of the gastrointestinal tract. These lesions can be recognised in association with prevalent underlying gastrointestinal conditions, such as Barrett oesophagus, chronic atrophic gastritis, and inflammatory bowel disease. The diagnosis of these special types can be challenging, and their biological behaviours are not fully characterised. The aim of this review is to provide a global view of non-conventional dysplastic lesions observed in the various segments of the tubular gastrointestinal tract and describe their salient features. Furthermore, as the clinical implications of these various subtypes have not been broadly tested in practice and are not represented in most management guidelines, we offer guidance on the best management practices for these lesions.

Helicobacter Infection and Gastric Adenoma

Background: We aimed to provide insight into the actual frequencies of gastric adenoma types and their association with gastritis status and associated mucosal changes with a focus on Helicobacter infection and the operative link on gastritis assessment (OLGA)/operative link on gastric intestinal metaplasia assessment (OLGIM) staging. Methods: From the archive of the Institute of Pathology in Bayreuth, we collected a consecutive series of 1058 gastric adenomas diagnosed between 1987 and 2017. Clinicopathological parameters retrieved from diagnostic reports included adenoma type and localization, associated mucosal changes in antrum and corpus (i.e., type of gastritis, the extent of intestinal metaplasia and atrophy), gender, date of birth, and date of diagnosis. Results: Intestinal-type adenoma was the most frequent adenoma (89.1%), followed by foveolar-type adenoma (4.3%), pyloric gland adenoma (3.4%), adenomas associated with hereditary tumor syndromes (2.8%), and oxyntic gland adenoma (0.4%). Adenomas were found in the background of Helicobacter pylori (H. pylori) gastritis in 23.9%, Ex-H. pylori gastritis in 36.0%, autoimmune gastritis in 24.8%, chemical reactive gastritis in 7.4%, and others in 0.1%. More than 70% of patients with gastric adenomas had low-risk stages in OLGA and OLGIM. Conclusions: We found a higher frequency of foveolar-type adenoma than anticipated from the literature. It needs to be questioned whether OLGA/OLGIM staging can be applied to all patients.

The pathology of gastric and duodenal polyps: current concepts

The liberal use of upper endoscopy has led to an increased detection of gastric and duodenal polyps, which are identified in as many as 6 and 4.6% of patient examinations, respectively. Gastroduodenal polyps are a heterogeneous group of lesions that can be neoplastic or non-neoplastic (e.g. hyperplastic or heterotopical). Most polyps present characteristic topographical features, as well as endoscopic appearance and size. Evaluation of the surrounding mucosa is essential in assessing the underlying pathology (e.g. Helicobacter pylori, autoimmune gastritis or inherited polyposis syndromes). Phylogenetically, gastric and duodenal polyps can be classified according to the epithelial compartment from which they derive. Polyps that arise from the surface epithelium can either be of foveolar or intestinal type, and they can develop from either the native mucosa or the metaplastic epithelium (gastric intestinal metaplasia or duodenal foveolar metaplasia). Other polyps develop from the deeper glandular component, such as pyloric/oxyntic gland derived subtypes. In this review we focus upon epithelial polyps, with an emphasis on the most common and clinically relevant lesions, and present recently described entities.

Clinicopathological features and risk factors for lymph node metastasis in early-stage non-ampullary duodenal adenocarcinoma

BACKGROUND

Management strategies for primary non-ampullary duodenal adenocarcinoma (NADAC) in early stage are not well established given its low incidence. This study aimed to elucidate clinicopathological features of early NADAC, including risk for lymph nodal metastasis (LNM).

METHODS

In total, 166 patients with early NADAC underwent initial treatment at our institution between 2006 and 2019, of whom 153 had intramucosal (M-) and 13 had submucosal (SM-) NADAC. These endoscopic and pathological features were retrospectively analyzed. Risk factors for LNM were evaluated in 46 early NADAC patients who underwent surgery with lymph node dissection.

RESULTS

Compared with M-NADAC, SM-NADAC was significantly more frequently located at the proximal side of the papilla, with mixed elevated and depressed macroscopic type, histologically poorly differentiated tumor and lymphovascular invasion (LVI) (85% vs. 47%, P = 0.009; 54% vs. 5%, P < 0.001; 23% vs. 0%, P < 0.001; and 46% vs. 0%, P < 0.001, respectively). The frequency of LNM was significantly higher in SM-NADAC than in M-NADAC (5/12, 42% vs. 0/34, 0%; P < 0.001). In SM-NADAC, the frequency of LNM was higher in poorly differentiated than in well to moderately differentiated tumors (3/3, 100% vs. 2/9, 22%) and higher in tumors with LVI than in those without LVI (3/5, 60% vs. 2/7, 29%). Regarding invasion depth, 2 of 4 patients with SM invasion (400 ≤ × < 500 µm) showed LNM. However, in this study, no patients developed very shallow SM invasion (0 < × < 400 µm).

CONCLUSIONS

SM-NADAC showed high LNM risk. Surgical treatment with regional lymph node dissection is recommended as a treatment strategy for SM-NADAC.

The clinicopathological and molecular features of sporadic gastric foveolar type neoplasia

Gastric intraepithelial foveolar type neoplasia (IEFN) is not well defined. In addition, atrophic mucosa (AM) is an important issue to consider when evaluating gastric tumorigenesis. Here, we assessed the clinicopathological characteristics and molecular alterations contributing to the development of IEFN compared with intestinal type neoplasia. We examined the clinicopathological and molecular features of 42 cases of IEFN with low-grade dysplasia (LGD) and those of 77 cases of intraepithelial intestinal type neoplasia (IEIN) with LGD. The clinicopathological and molecular features examined included the AM status, mucin phenotype expression, CDX2 expression, p53 overexpression, β-catenin intranuclear accumulation, microsatellite instability (MSI), DNA methylation status (low methylation epigenotype [LME], intermediate ME, or high ME), allelic imbalances (AIs), and APC promoter 1B mutations. There were no differences in the frequencies of AM and rates of CDX2 expression between IEFN and IEIN cases. Although no differences in the frequencies of p53 overexpression and MSI were observed between the two histological types, intranuclear expression of β-catenin was significantly higher in IEIN than in IEFN. In addition, although the rate of LME was significantly higher in IEFN cases than in IEIN cases, IEFN was characterized by AIs at multiple foci. Finally, mutation of the APC promoter 1B, which is a characteristic of gastric adenocarcinoma and proximal polyposis of the stomach (potentially resembling IEFN), was detected in only one IEFN case. These findings suggested that IEFN may be an independent entity in terms of molecular alterations including the presence of multiple AIs and LME.

Histopathologic Diagnosis of Atrophic Gastritis and Intestinal Metaplasia

Atrophic gastritis and intestinal metaplasia are well-known to be reliable indicators of gastric cancer risk. They are clinically important in deciding whether to recommend endoscopic surveillance. Herein I review the histopathologic diagnosis of atrophic gastritis and IM. Gastric atrophy is divided into metaplastic atrophy and non-metaplastic atrophy. IM is categorized as complete (type I) and incomplete (type II, III). Systematic interpretation of gastric atrophy and IM using the updated Sydney system or operative link on gastritis assessment is recommended. Furthermore, I suggest using the consensus definition of gastric atrophy and incomplete IM in the gastric biopsy pathology report to support the surveillance of high-risk gastric cancer group.

Phenotypic variations of gastric neoplasms in familial adenomatous polyposis are associated with endoscopic status of atrophic gastritis

BACKGROUND AND AIM

Gastric neoplasms (GN), including gastric adenoma and carcinoma, are well known as extracolonic manifestations of familial adenomatous polyposis (FAP). We aimed to investigate the clinicopathological features of GN in FAP patients and to clarify their relationship with the endoscopic status of the background mucosa.

METHODS

We analyzed the records of 39 patients who were diagnosed with FAP and underwent esophagogastroduodenoscopy between April 2005 and July 2016. Patients were divided into two groups according to atrophic gastritis (AG) status. Endoscopic findings of GN and background mucosa, and histopathological findings, including phenotypic expression of GN and mutation locus of adenomatous polyposis coli (APC) gene, were evaluated.

RESULTS

Gastric neoplasms were more predominant in the AG-positive group than in the AG-negative group (6/9, 66.7% vs 7/30, 23.3%; P = 0.039). Of 36 GN detected in 13 patients, six GN in five patients were followed and 30 GN in eight patients were endoscopically resected and analyzed. GN in the AG-negative group frequently showed whitish color, were located in the proximal stomach, and presented the gastric immunophenotype compared to GN in the AG-positive group. All GN were intramucosal lesions and were curatively resected regardless of AG status. APC germline mutations were identified in 32 patients. In patients with GN, a significantly higher number of mutation loci were among exons 10-15 (codons 564-1465).

CONCLUSION

Clinicopathological characteristics and phenotypic expressions of GN in FAP patients depend on background mucosa status with or without AG. These findings are useful for detecting GN in FAP patients.

British Society of Gastroenterology guidelines on the diagnosis and management of patients at risk of gastric adenocarcinoma

Gastric adenocarcinoma carries a poor prognosis, in part due to the late stage of diagnosis. Risk factors include Helicobacter pylori infection, family history of gastric cancer-in particular, hereditary diffuse gastric cancer and pernicious anaemia. The stages in the progression to cancer include chronic gastritis, gastric atrophy (GA), gastric intestinal metaplasia (GIM) and dysplasia. The key to early detection of cancer and improved survival is to non-invasively identify those at risk before endoscopy. However, although biomarkers may help in the detection of patients with chronic atrophic gastritis, there is insufficient evidence to support their use for population screening. High-quality endoscopy with full mucosal visualisation is an important part of improving early detection. Image-enhanced endoscopy combined with biopsy sampling for histopathology is the best approach to detect and accurately risk-stratify GA and GIM. Biopsies following the Sydney protocol from the antrum, incisura, lesser and greater curvature allow both diagnostic confirmation and risk stratification for progression to cancer. Ideally biopsies should be directed to areas of GA or GIM visualised by high-quality endoscopy. There is insufficient evidence to support screening in a low-risk population (undergoing routine diagnostic oesophagogastroduodenoscopy) such as the UK, but endoscopic surveillance every 3 years should be offered to patients with extensive GA or GIM. Endoscopic mucosal resection or endoscopic submucosal dissection of visible gastric dysplasia and early cancer has been shown to be efficacious with a high success rate and low rate of recurrence, providing that specific quality criteria are met.

Clinicopathological characteristics of non-ampullary duodenal tumors and their phenotypic classification

The tumorigenesis of non-ampullary duodenal epithelial tumors (NADETs) might be different between the oral and anal sides of Vater's papilla. We conducted an immunohistological review to elucidate the clinicopathological features according to the tumor location and phenotypic classification. A review of an institutional database identified 121 patients with 125 superficial NADETs. NADETs were histologically evaluated and classified into the intestinal or gastric type based on immunohistochemical analysis. Clinicopathological factors were compared based on the tumor location and phenotype. Logistic regression analysis was performed to identify independent predictors for gastric-type NADETs. According to location analysis, the mucin phenotype was significantly different (oral side, intestinal-type 64.8%, gastric-type 35.3%; anal side, intestinal-type 87.3%, gastric-type 12.7%; P < 0.01). Although the incidence of adenoma was significantly predominant in the intestinal type (75.3%), most gastric-type NADETs were cancerous (64.3%). Notably, most gastric-type NADETs were adenocarcinomas even when the tumor size was ≤0 mm. In multivariate analysis, tumor location on the oral side (odds ratio [OR], 4.42), villous structure (OR, 6.44), and low tumor gland density (OR, 9.49) were independent predictors of gastric-type tumors. Gastric-type NADETs significantly differ from intestinal-type NADETs in terms of tumor location, morphology, and biology.

Gastric foveolar-type adenomas endoscopically showing a raspberry-like appearance in the Helicobacter pylori -uninfected stomach

Background and study aims  Foveolar-type adenoma is described as a very rare tumor that occurs in individuals without Helicobacter pylori (HP) infection and diagnosed as adenocarcinoma in the Japanese Classification of Gastric Carcinoma (JCGC). However, we have frequently encountered patients with foveolar-type adenoma that endoscopically resembles a hyperplastic polyp, suggesting that it has just been overlooked to date. Here, we analyzed clinicopathological characteristics of a special subtype of foveolar-type adenoma showing specific endoscopic findings. Patients and methods  From a total of 212 patients with gastric cancer resected during a 22-month period, we enrolled 14 (6.6 %) diagnosed with foveolar-type adenoma (adenocarcinoma in JCGC). HP infection status was determined by eradication history, HP serum IgG antibody level, urea breath test, and endoscopic and histological findings. All lesions were observed using white-light endoscopy and narrow-band imaging with magnification endoscopy (NBIME). Endoscopically resected lesions were histologically examined. Results  None of 14 patients had a current or past history of HP infection. All lesions were visualized on non-atrophic gastric mucosa as small reddish protrusions with fine granular surface, showing a raspberry-like appearance. NBIME showed papillary or gyrus-like microstructures with irregular capillary. Lesions were histologically diagnosed as foveolar-type adenoma showing MUC5AC-positive gastric mucin phenotype. Ki-67 was overexpressed (median labeling index 69.9 %, range 28.4 - 92.1 %), though all lesions were an intraepithelial tumor without stromal invasion. p53 over-staining was not seen in any. Conclusions  Raspberry-like lesions on non-atrophic gastric mucosa in HP-uninfected individuals should be evaluated for the possibility of a special subtype of foveolar-type adenoma.

Gastric pyloric gland adenoma: a multicentre clinicopathological study of 67 cases

AIMS

There is limited information regarding the clinicopathological and immunohistochemical characteristics of gastric pyloric gland adenomas (PGAs).

METHODS AND RESULTS

Sixty-seven cases of gastric PGA from 57 patients were analysed. PGAs occurred with similar frequency in men and women (47.4 and 52.6%, respectively), with a mean age of 66 years. Most presented in the gastric body/fundus (67.2%). Fifteen cases (22.4%) developed against a background of autoimmune gastritis (AIG), whereas normal mucosa was seen in 35.8%. Only 16.4% (11 cases) developed in patients with a genetic predisposition, most commonly familial adenomatous polyposis. Low-grade lesions had a mean size of 1.5 cm, while PGAs with high-grade dysplasia (HGD) or adenocarcinoma had a mean size of 3.5 cm (P < 0.001) and more commonly showed tubulovillous architecture (50.0 versus 25.6% in low-grade dysplasia; P = 0.040). Most PGAs (61.2%) co-expressed mucin (MUC)5AC and MUC6 (mixed type), which was associated significantly with HGD or adenocarcinoma (P = 0.013). AIG was also associated with HGD (P = 0.027), but genetic predisposition did not correlate with the grade of dysplasia (P = 0.793). The recurrence rate of PGA was similar for high- (11.8%) and low-grade lesions (7.4%) (P = 0.624).

CONCLUSIONS

The risk of HGD increases with the size of PGA, tubulovillous architecture and the presence of AIG as well as mixed immunophenotype. As the overall local recurrence rate is less than 10%, PGAs may be treated conservatively, but they should be excised completely if possible, particularly if they are large or show high-grade features.

Neoplastic Lesions of Gastric Adenocarcinoma and Proximal Polyposis Syndrome (GAPPS) Are Gastric Phenotype

Neoplastic lesions of gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) are gastric phenotype. GAPPS was reported in 2011 as a new autosomal dominant gastric polyposis syndrome characterized by involvement of the gastric body/fundus with sparing of the antrum by multiple polyps, reported to be primarily fundic gland polyps (FGPs), with progression to dysplasia and adenocarcinoma of intestinal type. Our series consists of 51 endoscopic biopsies and 5 gastrectomy specimens from 25 patients belonging to a previously defined GAPPS family. Slides were reviewed and further stains performed. Endoscopy was abnormal in 15 of the 25 patients: carpeting polyposis of the gastric body and fundus in 14 and a gastric mass without polyposis in one. The most common polypoid lesion (seen in 12 patients) was a disorganized proliferation of specialized/oxyntic glands high up in the mucosa involving the attenuated foveolar region around the gastric pits, which we have termed "hyperproliferative aberrant pits". Well developed FGP were seen in 10 patients. Established neoplastic lesions seen in 9 patients were: (1) discrete gastric adenomas, (2) multifocal "flat" dysplasia in the setting of hyperproliferative aberrant pits +/- FGPs, (3) adenomatous tissue associated with adenocarcinoma. All cases of dysplasia were of gastric phenotype based on morphology and mucin immunohistochemistry.

IN CONCLUSION

(1) the spectrum of gastric pathology associated with GAPPS is wider than previously reported, (2) the earliest microscopic clue is the finding of hyperproliferative aberrant pits, and (3) the dysplasia is gastric phenotype and the subsequent adenocarcinoma may follow the gastric pathway of carcinogenesis.

Occurrence of metachronous or synchronous lesions after endoscopic treatment of gastric epithelia dysplasia- impact of histologic features of background mucosa

AIMS

Endoscopic resection is a safe and effective method to treat gastric epithelia dysplasia (GED). However, the development of metachronous and synchronous lesions after treatment has become a major concern. In this study, we investigated clinicopathologic features of 105 GED lesions from endoscopic resections between January 2008 and December 2009. Our goal is to find histologic factors that predict synchronous and metachronous lesions after ESD treatment. We assessed the degree of intestinal metaplasia (IM) and atrophy, type of IM, presence of gastritis cystica profunda, and crypt dysplasia in the adjacent mucosa.

METHODS AND RESULTS

We divided 105 GED lesions into three groups: a single group without metachronous or synchronous GED or adenocarcinoma (n=35); a multiple synchronous group (n=30, group with synchronous occurrence of GED or adenocarcinoma after treatment); and a multiple metachronous group (n=40, group with metachronous occurrence of GED or adenocarcinoma after treatment). The multiple metachronous and synchronous groups showed larger sizes (p=0.003) and higher grades (p=0.021) as compared with the single group. Furthermore, marked IM and atrophy in adjacent mucosa were more easily seen in the multiple metachronous and synchronous groups as compared with the single group (p<0.0001). Interestingly, the presence of incomplete type of IM (p=0.025) and crypt dysplasia (p<0.0001) in background mucosa was associated with occurrence of metachronous and synchronous lesions following endoscopic resection of GED.

CONCLUSIONS

The histological features of background mucosa, such as intestinal metaplasia, atrophy, and crypt dysplasia could be used as indicators of occurrence of metachronous and synchronous lesions after endoscopic treatment of GED.

Magnifying Endoscopy with Narrow Band Imaging of Early Gastric Cancer: Correlation with Histopathology and Mucin Phenotype

Background/Aims

Magnifying endoscopy with narrow band imaging (ME-NBI) is a useful modality for the detailed visualization of microsurface (MS) and microvascular (MV) structures in the gastrointestinal tract. This study aimed to determine whether the MS and MV patterns in ME-NBI differ according to the histologic type, invasion depth, and mucin phenotype of early gastric cancers (EGCs).

Methods

The MS and MV patterns of 160 lesions in 160 patients with EGC who underwent ME-NBI before endoscopic or surgical resection were prospectively collected and analyzed. EGCs were categorized as either differentiated or undifferentiated and as either mucosal or submucosal, and their mucin phenotypes were determined via immunohistochemistry of the tumor specimens.

Results

Differentiated tumors mainly displayed an oval and/or tubular MS pattern and a fine network or loop MV pattern, whereas undifferentiated tumors mainly displayed an absent MS pattern and a corkscrew MV pattern. The destructive MS pattern was associated with submucosal invasion, and this association was more prominent in the differentiated tumors than in the undifferentiated tumors. MUC5AC expression was increased in lesions with either a papillary or absent MS pattern and a corkscrew MV pattern, whereas MUC6 expression was increased in lesions with a papillary MS pattern and a loop MV pattern. CD10 expression was more frequent in lesions with a fine network MV pattern.

Conclusions

ME-NBI can be useful for predicting the histopathology and mucin phenotype of EGCs.

Negative pathology after endoscopic resection of gastric epithelial neoplasms: importance of pit dysplasia

BACKGROUND/AIMS

Endoscopic resection (ER) is a well-established treatment modality for gastric epithelial neoplasm. However, there is a discrepancy between forceps biopsy and ER specimen pathology, including a negative pathologic diagnosis (NPD) after ER. It has been suggested that pit dysplasia (PD) is a subtype of gastric dysplasia, and the aim of this study was to assess the significance of PD in cases with NPD after ER for early gastric neoplasms.

METHODS

After ER, 29 NPD lesions that had an associated pretreatment forceps biopsy specimen, were correctly targeted during ER, and had no cautery artifact on the resected specimen were included in this study.

RESULTS

Sixteen lesions showed PD and 13 had no neoplastic pathology. The initial pretreatment forceps biopsy diagnoses of 29 NPD lesions were low-grade dysplasia (LGD) in 17 lesions, high-grade dysplasia (HGD) in seven lesions, and adenocarcinoma in five lesions, which after review were revised to PD in 19 lesions, LGD in four lesions, adenocarcinoma in two lesions, and no neoplastic pathology in four lesions. Overall, nine lesions (31%) were small enough to be removed by forceps biopsy, four NPD lesions (14%) were initially misinterpreted as neoplastic lesions, and 16 PD lesions (55%) were misinterpreted as NPD lesions on ER slides.

CONCLUSIONS

Approximately half of the lesions initially diagnosed as LGD or HGD were subsequently classified as PD. Therefore, including PD as a subtype of gastric dysplasia could reduce the diagnostic discrepancy between initial forceps biopsy and ER specimens.

Circulating tumor cells detected by lab-on-a-disc: Role in early diagnosis of gastric cancer

BACKGROUND

The use of circulating tumor cells (CTCs) as an early diagnostic biomarker and prognostic indicator after surgery or chemotherapy has been suggested for various cancers. This study aimed to evaluate CTCs in patients who underwent gastrectomy for gastric cancer and to explore their clinical usefulness in the early diagnosis of gastric cancer.

METHODS

A total of 116 patients with gastric cancer who underwent gastrectomy and 31 healthy volunteers were prospectively included between 2014 and 2015. Peripheral blood samples were collected before gastrectomy, and CTCs were examined using a centrifugal microfluidic system with a new fluid-assisted separation technique.

RESULTS

After creating a receiver operating characteristic curve to identify the discriminative CTC value needed differentiate patients with gastric cancer from healthy volunteers, sensitivity and specificity were nearly optimized at a CTC threshold of 2 per 7.5 mL of blood. Of the 102 persons with a CTC level ≥2 per 7.5 mL of blood, 99 (97.1%) had gastric cancer, and of the 45 persons with a CTC level <2 per 7.5 mL of blood, 28 (62.2%) were healthy controls. Accordingly, the sensitivity and specificity for the differentiation of patients with gastric cancer from healthy controls were 85.3% and 90.3%, respectively. However, the presence of CTCs was not associated with any clinicopathologic features such as staging, histologic type, or mucin phenotype.

CONCLUSION

Although we could not prove the clinical feasibility of CTCs for gastric cancer staging, our results suggest a potential role of CTCs as an early diagnostic biomarker of gastric cancer.

Extra-ampullary duodenal adenoma: a clinicopathological study

AIMS

Extra-ampullary duodenal adenoma (EADA) is a rare condition with poorly described clinicopathological details. In this study, we aimed to characterize EADA clinicopathologically.

METHODS AND RESULTS

We performed a retrospective review of 44 serial cases of EADA. Each EADA was categorized as either gastric-type (n = 5) or intestinal-type (n = 39). All gastric-type adenomas were located in the first portion of the duodenum and exhibited a pedunculated shape. Gastric-type adenomas were classified into two subtypes: pyloric gland and foveolar. The former consisted of mucin 6 (MUC6)-positive glands covered with MUC5AC-positive cells, whereas nearly all the latter consisted of MUC5AC-positive cells. When EADAs were categorized into high and low grades, approximately 40% (16 of 44) were high-grade. The high-grade adenomas were significantly larger than the low-grade adenomas (19.4 ± 8.6 mm versus 11.8 ± 5.1 mm, P = 0.021), and all adenomas greater than 20 mm in largest diameter were categorized as high-grade adenomas. Among 16 individuals who underwent total colonoscopy before or after duodenal mucosal resection, nine had a colorectal neoplasm, and all nine duodenal lesions were of the intestinal phenotype.

CONCLUSIONS

We clarified the clinicopathological characteristics of gastric- and intestinal-type EADAs. EADAs greater than 20 mm at the largest diameter were consistently high-grade, and are thought to have the potential to progress to adenocarcinoma. These findings should be helpful for the clinical management of EADA.

Gastric foveolar dysplasia: a survey of reporting habits and diagnostic criteria

This study aimed to ascertain views, incidence of reporting and diagnostic criteria for gastric foveolar dysplasia. A questionnaire, a post-questionnaire discussion and microscopic assessment of selected cases was conducted by gastrointestinal pathologists to explore the above-stated aims. Fifty-four percent of respondents never or rarely diagnosed gastric foveolar-type dysplasia. The general consensus was that round nuclei, lack of nuclear stratification, presence of inflammation/damage and surface maturation favoured reactive change; while architectural abnormalities/complexity and nuclear enlargement mainly were used to separate low-grade from high-grade foveolar dysplasia. Immunohistochemistry was rarely used to make the diagnosis of dysplasia and was thought not to be of help in routine practice. Inter-observer agreement in grading of dysplasia versus reactive, and the type of dysplasia (foveolar versus adenomatous), was substantial/almost perfect amongst 35.7% and 21.4% of participants, respectively. This reflects low reproducibility in making these diagnoses. In conclusion, foveolar dysplasia was a rarely made diagnosis among 14 gastrointestinal pathologists, there are no uniform criteria for diagnosis and there is poor inter-observer agreement in separating low-grade foveolar dysplasia from reactive gastric mucosa and low-grade adenomatous dysplasia. Greater awareness and agreed criteria will prevent misdiagnosis of low-grade foveolar dysplasia as reactive, and vice versa.

Practical Points in Gastric Pathology

CONTEXT

-The diagnosis of gastric epithelial lesions is difficult in clinical practice, even with the recent developments and advances in endoscopic modalities, owing to the diverse morphologic features of the lesions, lack of standardized diagnostic criteria, and the high intraobserver and interobserver variabilities in the nonneoplastic (regenerative)-neoplastic spectrum.

OBJECTIVE

-To provide an overview of the current concepts and unresolved issues surrounding the diagnosis of diseases in the nonneoplastic-neoplastic spectrum, and to discuss some noteworthy properties and histologic features of gastric epithelial lesions.

DATA SOURCES

-A comprehensive assessment of the medical literature on gastric epithelial lesions was performed; we also interjected our own experiences into the discussion. Sources included original studies, review articles, and textbooks related to the field.

CONCLUSIONS

-Our literature review revealed that clear cell changes and micropapillary carcinoma components in gastric carcinomas are associated with poor clinical outcomes and should hence be included in pathologic reports. Moreover, we suggest a stepwise biopsy-endoscopic resection modality for the diagnosis of borderline neoplasia-nonneoplasia cases.

Colorectal cancer in Crohn's colitis is comparable to sporadic colorectal cancer

PURPOSE

It is now recognized that Crohn's disease (CD), similar to ulcerative colitis (UC), carries an up to 20-fold higher cancer risk, and the development of colorectal carcinoma (CRC) is a major long-term complication. Once CRC is present, molecular profiling is one of the components in selecting appropriate treatment strategies; however, in contrast to UC, genetic alterations in Crohn's colitis-associated CRC are poorly understood.

METHODS

In a series of 227 patients with Crohn's colitis, we identified 33 cases of CRC (~14 %) and performed targeted mutational analysis of BRAF/KRAS/NRAS and determined microsatellite status as well as immunophenotype of the tumors.

RESULTS

In the CRC cohort, the median age at time of cancer diagnosis was 58 (range 34-77 vs. 59.5 in sporadic; P = 0.81) and the median CD duration was 29 years (range 6-45). As a group, CRC complicating Crohn's colitis is BRAF (97 %) and NRAS (100 %) wild type and the vast majority is microsatellite stable (94 %); KRAS-mutations were found in six cases (18 %). Stage grouping, anatomic distribution, and overall survival were similar to sporadic CRC; however, long-standing CD (≥25 years) as well as gastric-immunophenotype (MUC5AC+) was associated with significantly shorter overall survival (P = 0.0029; P = 0.036, respectively).

CONCLUSION

In summary, the clinicopathological and molecular profile of CD-associated CRC is similar to that observed in sporadic CRC.

HER2 Status in Premalignant, Early, and Advanced Neoplastic Lesions of the Stomach

Objectives. HER2 expression in gastric cancer (GC) has received attention as a potential target for therapy with Trastuzumab. We reviewed the current knowledge on HER2 status in premalignant gastric lesions and in early (EGC) and advanced (AGC) GC to discuss the possible pathogenetic and prognostic roles of HER2 overexpression in GC. Results. HER2 overexpression was documented in gastric low-grade (LG) and high-grade intraepithelial neoplasia (HG-IEN), with higher frequency in gastric type dysplasia. HER2 overexpression was significantly associated with disease recurrence and poor prognosis in EGC representing an independent risk factor for lymph node metastases. HER2 overexpression was more frequent in AGC characterized by high grade, advanced stage, and high Ki-67 labeling index. The discordance in HER2 status was evidenced between primitive GC and synchronous or metachronous metastases. Conclusions. HER2 overexpression in premalignant gastric lesions suggests its potential involvement in the early steps of gastric carcinogenesis. The assessment of HER2 status in EGC may be helpful for the identification of patients who are at low risk for developing nodal metastases. Finally, the possible discordance in HER2 status between primary GC and its synchronous metastases support routine assessment of HER2 both in the primary GC and in its metastatic lesions.

Epithelial dysplasia of the stomach with gastric immunophenotype shows features of biological aggressiveness

BACKGROUND

Gastric dysplasia is classified as adenomatous/type I (intestinal phenotype) and foveolar or pyloric/type II (gastric phenotype) according to morphological (architectural and cytological) features. The immunophenotypic classification of dysplasia, based on the expression of the mucins, CD10 and CDX2, recognizes the following immunophenotypes: intestinal (MUC2, CD10, and CDX2); gastric (MUC5AC and/or MUC6, absence of CD10, and absent or low expression of CDX2); hybrid (gastric and intestinal markers); and null.

METHODS

Sixty-six cases of nonpolypoid epithelial dysplasia of the stomach were classified according to morphological features (histotype and grade) and immunophenotype. Immunohistochemical staining was performed with antibodies against MUC2, MUC5AC, MUC6, CD10, CDX2, chromogranin, synaptophysin, Ki-67, and TP53. HER2 alterations were analyzed by immunohistochemistry and silver-enhanced in situ hybridization.

RESULTS

By conventional histology, dysplasia was classified as adenomatous/intestinal (n = 42; 64 %) and foveolar or pyloric/gastric (n = 24; 36 %) and graded as low grade (n = 37; 56 %) or high grade (n = 29; 44 %). Immunophenotypic classification showed intestinal (n = 22; 33.3 %), gastric (n = 25; 37.9 %), hybrid (n = 17; 25.8 %), or null (n = 2; 3.0 %) phenotypes. In 20 cases a coexistent intramucosal carcinoma was identified. The intestinal immunophenotype was shown to be significantly associated with low-grade dysplasia (p = 0.001), high expression of CDX2 (p = 0.015), TP53 (p = 0.034), synaptophysin (p = 0.003), and chromogranin (p < 0.0001); the gastric immunophenotype was significantly associated with high-grade dysplasia (p = 0.001), high Ki-67 proliferative index (p = 0.05), and coexistence of intramucosal carcinoma (p = 0.013). HER2 amplification was observed in 3 cases, typed as gastric or hybrid.

CONCLUSIONS

Epithelial nonpolypoid dysplasia of the stomach with gastric immunophenotype shows features of biological aggressiveness and may represent the putative precursor lesion in a pathway of gastric carcinogenesis originated de novo from the native gastric mucosa, leading to gastric-type adenocarcinoma.

Gastric pyloric gland adenoma

Pyloric gland adenomas are rare neoplasms of the gastrointestinal tract. Gastric pyloric gland adenomas have been shown to arise in chronically damaged mucosa. The neoplastic glands have gastric pyloric gland differentiation and have a tightly packed organization with occasional cystic dilatation. The individual cells are cuboidal to columnar, with eosinophilic to amphophilic cytoplasm and either no apical mucin cap or a poorly formed apical mucin cap. The nuclei are round to oval, with occasional prominent nucleoli. Immunohistochemically, the neoplastic cells label with markers of gastric pyloric gland differentiation, including MUC6 and MUC5AC. There is limited information regarding the natural history of pyloric gland adenomas, but clinical series have described adenocarcinomas in association with gastric pyloric gland adenomas. The ideal clinical management is adequate sampling of the lesion to investigate for high-grade dysplasia and/or invasive cancer and recommendation to clinical colleagues to investigate the background mucosa for the etiology of chronic gastritis as well as potential additional neoplastic lesions. This review will focus on gastric pyloric gland adenomas.

Gastric epithelial dysplasia: characteristics and long-term follow-up results after endoscopic resection according to morphological categorization

Background

Gastric epithelial dysplasia (GED) can be morphologically categorized into adenomatous and foveolar types. To date, there have been few studies on the clinical characteristics of GEDs according to the morphologic types. Therefore, we here aimed to elucidate the clinicopathologic characteristics of patients with GED and the long-term follow-up results after endoscopic resection according to the morphologic characteristics of GEDs.

Methods

A total of 357 patients who underwent endoscopic resection for GEDs at Pusan National University Hospital between January 2008 and December 2009 were included in the study. GEDs were morphologically categorized into adenomatous, foveolar, and hybrid types on histologic examination. The clinicopathologic characteristics of patients with GEDs and outcomes of endoscopic resection were analyzed.

Results

Patients with GED were divided into 3 groups: adenomatous (n = 167, 46.8%), foveolar (n = 103, 28.9%), and hybrid (n = 87, 24.3%) types. Compared to the adenomatous type, foveolar type lesions were more frequently located in the antrum/pylorus, flat/depressed lesions, and normal/reddish in color; and showed more frequent high-grade dysplasia. During the follow–up period (median, 37.3 months), the overall incidence of synchronous and metachronous lesions was 20.8% and 20.1%, respectively; of these, the incidence of synchronous and metachronous gastric cancer was 8.7% and 5.4%, respectively. There were no significant differences in the incidence of synchronous and metachronous lesions according to morphologic types.

Conclusion

GEDs appear to have different clinicopathologic characteristics according to morphologic types. Irrespective of the morphology, synchronous and metachronous gastric cancers are commonly found after endoscopic resection of GEDs. Therefore, close follow-up surveillance after endoscopic resection of GEDs should be performed for all patients.

Extra-ampullary duodenal adenocarcinoma

Extra-ampullary duodenal adenocarcinomas are rare, and when studied, frequently have been grouped with jejunoileal adenocarcinomas. Nevertheless, anecdotal experiences suggest that these neoplasms may present 2 or more distinct phenotypes. To better characterize these neoplasms, we performed a retrospective review of 38 cases with a special focus on the morphologic and immunophenotypic characteristics and their clinicopathologic significance. Our cohort of extra-ampullary duodenal adenocarcinomas was classified on the basis of the morphologic features into gastric type (n=19, 50%), intestinal type (n=14, 37%), pancreaticobiliary type (n=2, 5%), and others (n=3, 8%). Most gastric-type adenocarcinomas (n=18, 95%) developed in the proximal duodenum, whereas the other types were located equally in the proximal and distal duodenum. Intestinal-type dysplasia was present at the periphery of 8 (57%) intestinal-type adenocarcinomas, and 8 (42%) gastric-type adenocarcinoma were associated with gastric-type dysplasia. Gastric foveolar metaplasia (n=12) and Brunner gland hyperplasia (n=10) were exclusively recognized adjacent to gastric-type adenocarcinomas. Notably, intestinal-type histology and the absence of lymph node metastasis were significantly associated with favorable disease-free survival in univariate and multivariate analyses. In summary, this study demonstrated that 2 major subsets of extra-ampullary duodenal adenocarcinoma, intestinal type and gastric type, are associated with distinct histopathologic features and clinical behavior.

Mitochondrial DNA alterations in the progression of gastric carcinomas: unexplored issues and future research needs

Gastric cancer is the second most frequent cause of cancer death worldwide. Patients infected with Helicobacter pylori (H. pylori) are at increased risk of gastric cancer. H. pylori induces genomic instability in both nuclear and mitochondrial (mt) DNA of gastric epithelial cells. Changes in mtDNA represent an early event during gastric tumorigenesis, and thus may serve as potential biomarkers for early detection and prognosis in gastric carcinoma.This review article summarizes the mtDNA mutations that have been reported in gastric carcinomas and their precancerous conditions. Unexplored research topics, such as the role of mtDNA alterations in an alternative pathway of gastric carcinogenesis, are identified and directions for future research are suggested.

Magnifying endoscopy of gastric epithelial dysplasia based on the morphologic characteristics

AIM: To investigate the difference in magnifying endoscopic findings of gastric epithelial dysplasias (GEDs) according to the morphologic characteristics.

METHODS: This study included 46 GED lesions in 45 patients who underwent magnifying endoscopy using narrow band imaging (ME-NBI) before endoscopic resection. During ME-NBI, the microvascular and microsurface (MS) patterns and the presence of light blue crest (LBC) and white opaque substance were investigated. GEDs were categorized as adenomatous, foveolar, and hybrid types, and their mucin phenotype was evaluated.

RESULTS: Of the 46 lesions, 27 (59%) were categorized as adenomatous, 15 (32%) as hybrid, and the remaining 4 (9%) as foveolar. All adenomatous GEDs showed the round pit and/or tubular MS patterns, all foveolar GEDs showed the papillary pattern, and hybrid GEDs showed mixed patterns (P < 0.001). LBC was more frequently observed in adenomatous GEDs than in hybrid or foveolar GEDs (52%, 33%, 0%, respectively), although this difference was not significant (P = 0.127). The papillary MS pattern was associated with MUC5AC and MUC6 expression, and the round pit and/or tubular MS patterns were associated with CD10 expression.

CONCLUSION: The MS pattern in ME-NBI findings is useful for predicting the morphologic category and mucin phenotype of GEDs, and ME-NBI findings may guide decisions regarding GED treatment.

Differentiation reprogramming in gastric intestinal metaplasia and dysplasia: role of SOX2 and CDX2

AIMS

Intestinal metaplasia (IM), which results from de-novo expression of CDX2, and dysplasia are precursor lesions of gastric cancer that are associated with an increased risk for cancer development. There is much evidence suggesting a role for the transcription factor SOX2 in gastric differentiation. The aim of this study was to attempt to establish the relationship of SOX2 with CDX2 and with the differentiation reprogramming that characterizes gastric carcinogenesis, to assess their involvement in IM and dysplasia.

METHODS AND RESULTS

Characterization of gastric (SOX2, MUC5AC, and MUC6) and intestinal (CDX2 and MUC2) markers in normal gastric mucosa, in 55 foci of IM and in 26 foci of dysplasia, was performed by immunohistochemistry. SOX2 was expressed in the normal gastric mucosa, in the presumptive stem cell compartment, and was maintained in 7% of the complete (MUC5AC-negative) and 85% of the incomplete (MUC5AC-positive) IM subtypes. Twelve per cent of the dysplastic lesions expressed SOX2, and the association with MUC5AC was lost. CDX2 was present in all IMs and dysplastic lesions.

CONCLUSIONS

SOX2 is associated with gastric differentiation in incomplete IM and is lost in the progression to dysplasia, whereas CDX2 is acquired de novo in IM and maintained in dysplasia. This suggests that the balance between gastric and intestinal differentiation programmes impacts on the gastric carcinogenesis cascade progression.

Upper GI tract lesions in familial adenomatous polyposis (FAP): enrichment of pyloric gland adenomas and other gastric and duodenal neoplasms

Patients with familial adenomatous polyposis (FAP), an autosomal dominant cancer predisposition syndrome caused by mutations in the APC gene, develop neoplasms in both the upper and lower gastrointestinal (GI) tract. To clarify the upper GI tract lesions in FAP patients in a tertiary care setting, we reviewed specimens from 321 endoscopies in 66 patients with FAP. Tubular adenomas in the small bowel were the most common neoplasms (present in 89% of patients), although only 1 patient developed invasive carcinoma of the small bowel. Several types of gastric neoplasms were identified--65% of patients had at least 1 fundic gland polyp, and 23% of patients had at least 1 gastric foveolar-type gastric adenoma. Pyloric gland adenomas were also enriched, occurring in 6% of patients--this is a novel finding in FAP patients. Despite the high frequency of gastric neoplasms, only 1 patient developed carcinoma in the stomach. The very low frequency of carcinoma in these patients suggests that current screening procedures prevent the vast majority of upper GI tract carcinomas in patients with FAP, at least in the tertiary care setting.

Morphology and natural history of familial adenomatous polyposis-associated dysplastic fundic gland polyps

AIMS

Most patients with familial adenomatous polyposis (FAP) develop gastric fundic gland polyps, with many displaying low-grade dysplasia. This study evaluates the natural history and morphological phenotype of dysplasia in FAP-associated fundic gland polyps.

METHODS AND RESULTS

Patients with FAP and dysplastic fundic gland polyps (n = 24) were identified. Twenty-two of 24 FAP-associated dysplastic fundic gland polyps showed a gastric phenotype and two had mixed phenotype. During a mean 6.1-year follow-up (range 0.8-12.6 years) and 5.7 endoscopies (range 2-22), one patient (4%) was diagnosed with a fundic gland polyp with high-grade dysplasia, while 23 patients (96%) in this cohort had either no dysplasia or persistent low-grade dysplasia. Contemporary patients with sporadic fundic gland polyps with low-grade dyplasia had similar morphology and outcomes to the FAP-associated fundic gland polyp cohort. Dysplasia in fundic gland polyps (FAP-associated and sporadic) was associated less frequently with intestinal phenotype, high-grade dysplasia and the finding of concurrent or subsequent carcinoma compared to contemporary patients with sporadic gastric dysplasia not occurring in fundic gland polyps.

CONCLUSIONS

This cohort of patients with FAP-associated dysplastic fundic gland polyps rarely developed high-grade dysplasia and gastric adenocarcinoma was absent.

Barrett Esophagus: Evolving Concepts in Diagnosis and Neoplastic Progression

Surgical pathologists need to answer 2 questions when evaluating biopsies from the distal esophagus or gastroesophageal junction in patients with a history of gastroesophageal reflux disease: Are the findings consistent with Barrett esophagus? and Is there any evidence of dysplasia? Pathologists should be well informed about the controversy around the definition of Barrett esophagus and the common pitfalls that lead to a false-positive diagnosis of Barrett esophagus or Barrett esophagus-associated dysplasia. A concise description of distinct morphologic types of dysplasia in Barrett esophagus and a summary of recent data on the natural history of BE are provided in this review.

Gastrointestinal dysplasia

The term dysplasia (intraepithelial neoplasia) is used to refer to neoplastic but non-invasive epithelium. Dysplasia in the gastrointestinal tract is considered a carcinoma precursor and a marker of high cancer risk for the site at which it is found. It is diagnosed by pathologists using a set of cytological and architectural features. There are many pitfalls in the diagnosis of gastrointestinal dysplasia. One reason for difficulty in dysplasia diagnosis is the significant heterogeneity in the appearances of each grade of dysplasia. In addition, the features that characterise dysplasia are only subtly different from those of regenerating epithelium, particularly at the low end of the spectrum, making this distinction difficult. For these reasons, and because of significant implications of this diagnosis for patient care, the interpretations of biopsies taken for dysplasia surveillance are considered challenging by most pathologists. In this article, we review definition, classification, and histological features and grading of gastrointestinal dysplasia with focus on Barrett's oesophagus (BE) related dysplasia, gastric epithelial dysplasia (GED) and dysplasia arising in the background of inflammatory bowel disease (IBD). We also discuss observer variability and the role of adjunctive markers in dysplasia diagnosis, and limitation with regard to surveillance of patients with BE and IBD due to sampling error.

Pathology of gastric cancer and its precursor lesions

Gastric cancers are a histologically heterogenous group of neoplasms arising from unique epidemiologic and molecular backgrounds. There is accumulating evidence that the intestinal type of gastric adenocarcinoma develops through a multistep process beginning with chronic gastritis triggered primarily by Helicobacter pylori and progressing through atrophy, intestinal metaplasia, and dysplasia (intraepithelial neoplasia) to carcinoma. Loss of E-cadherin expression resulting from CDH1 gene alterations is the primary carcinogenetic event in hereditary diffuse gastric cancer. Proximal gastric adenocarcinomas likely result from either gastroesophageal reflux or H pylori gastritis. This article provides an update of the histologic, immunohistochemical, and molecular pathways of gastric cancer and its precursors.