Gastric pit dysplasia in adjacent gastric mucosa in 414 gastric cancers: prevalence and characteristics

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.

Gastric Intestinal Metaplasia: Real Culprit or Innocent Bystander as a Precancerous Condition for Gastric Cancer?

Gastric intestinal metaplasia (GIM), which denotes conversion of gastric mucosa into an intestinal phenotype, can occur in all regions of the stomach, including cardiac, fundic, and pyloric mucosa. Since the earliest description of GIM, its association with gastric cancer of the differentiated (intestinal) type has been a well-recognized concern. Many epidemiologic studies have confirmed GIM to be significantly associated with subsequent gastric cancer development. Helicobacter pylori, the principal etiologic factor for gastric cancer, plays the most important role in predisposing to GIM. Although the role of GIM in the stepwise progression model of gastric carcinogenesis (the so-called "Correa cascade") has come into question recently, we review the scientific evidence that strongly supports this long-standing model and propose a new progression model that builds on the Correa cascade. Eradication of H pylori is the most important method for preventing gastric cancer globally, but the effect of eradication on established GIM, is limited, if any. Endoscopic surveillance for GIM may, therefore, be necessary, especially when there is extensive corpus GIM. Recent advances in image-enhanced endoscopy with integrated artificial intelligence have facilitated the identification of GIM and neoplastic lesions, which will impact preventive strategies in the near future.

A deep learning-based model improves diagnosis of early gastric cancer under narrow band imaging endoscopy

BACKGROUND

Diagnosis of early gastric cancer (EGC) under narrow band imaging endoscopy (NBI) is dependent on expertise and skills. We aimed to elucidate whether artificial intelligence (AI) could diagnose EGC under NBI and evaluate the diagnostic assistance of the AI system.

METHODS

In this retrospective diagnostic study, 21,785 NBI images and 20 videos from five centers were divided into a training dataset (13,151 images, 810 patients), an internal validation dataset (7057 images, 283 patients), four external validation datasets (1577 images, 147 patients), and a video validation dataset (20 videos, 20 patients). All the images were labeled manually and used to train an AI system using You look only once v3 (YOLOv3). Next, the diagnostic performance of the AI system and endoscopists were compared and the diagnostic assistance of the AI system was assessed. The accuracy, sensitivity, specificity, and AUC were primary outcomes.

RESULTS

The AI system diagnosed EGCs on validation datasets with AUCs of 0.888-0.951 and diagnosed all the EGCs (100.0%) in video dataset. The AI system achieved better diagnostic performance (accuracy, 93.2%, 95% CI, 90.0-94.9%) than senior (85.9%, 95% CI, 84.2-87.4%) and junior (79.5%, 95% CI, 77.8-81.0%) endoscopists. The AI system significantly enhanced the performance of endoscopists in senior (89.4%, 95% CI, 87.9-90.7%) and junior (84.9%, 95% CI, 83.4-86.3%) endoscopists.

CONCLUSION

The NBI AI system outperformed the endoscopists and exerted potential assistant impact in EGC identification. Prospective validations are needed to evaluate the clinical reinforce of the system in real clinical practice.

Gastric Intestinal Metaplasia in Mucosa Adjacent to Gastric Cancers Is Rarely Associated With the Aneuploidy That Is Characteristic of Gastric Dysplasia or Cancer

Most gastric cancers (GCs) are thought to develop via gastric intestinal metaplasia (GIM)-dysplasia-carcinoma pathway. Patients with extensive and/or incomplete GIM have been reported to have a higher risk of GC. GIM can also display dysplasia-like cytoarchitectural atypia limited to the bases of gastric pits without surface involvement. However, only a small proportion of GIM patients will develop gastric neoplasia, and it remains questionable if GIM is a direct precursor. A cohort of 82 GC patients with GIM who underwent gastrectomy were analyzed. DNA flow cytometry was performed on 109 GIM samples (including 88 predominantly complete GIM and 21 predominantly incomplete GIM subclassified based on morphology) obtained from adjacent mucosa of the 82 GCs. Only 2 (2%) of the 109 GIM samples demonstrated aneuploidy, both from 2 minority patients (Asian and Hispanic) with limited and complete GIM and no cytoarchitectural atypia. The remaining 107 GIM samples showed mild to focally moderate basal gland (metaplastic) atypia limited to the bases of gastric pits, but they all demonstrated normal DNA content regardless of anatomic location, histologic GIM subtype, or varying degrees of basal gland atypia. In conclusion, the vast majority of the GIM samples (98%) lack the aneuploidy that is characteristic of gastric dysplasia or cancer. This indicates that aneuploidy usually occurs after the development of gastric dysplasia rather than at the stage of GIM. The finding also suggests that the presence of GIM alone may not be sufficient to suggest an increased risk for GC and that the inclusion of other high-risk features (ie, extensive GIM, dysplasia, racial minorities, and/or family history of GC in a first-degree relative) and/or aneuploidy ought to play a role in the selection of GIM patients who may warrant endoscopic surveillance. Finally, GIM with mild to focally moderate basal gland atypia is likely to represent metaplastic atypia in most cases.

Histomorphological Characteristics and Pathological Types of Hyperproliferation of Gastric Surface Epithelial Cells

Objective

To investigate the histomorphological characteristics and pathological types of hyperproliferation of gastric surface epithelial cells.

Methods

Hematoxylin and Eosin, Periodic acid–Schiff, and immunohistochemical staining were performed on biopsy specimens obtained from 723 patients with hyperproliferation of gastric surface epithelial cells and/or hyperplasia of gastric pits. Follow-up gastroscopic reexaminations were performed on 475 patients included. Improvement probability was analyzed using Kaplan-Meyer as well as Cox proportional hazards models.

Results

Seven different histomorphologies and clinicopathologies of hyperproliferation of gastric surface epithelial cells were identified: (1) common hyperplasia of gastric epithelial cells, which was characterized by focal glandular epithelial hyperplasia of gastric pits with chronic inflammation; (2) drug-induced hyperplasia of gastric epithelial cells, which was characterized by increased hyperplasia of gastric pits and cells arranged in a monolayer; (3) Helicobacter pylori (Hp) infection-induced hyperplasia of gastric epithelial cells, which was characterized by the disappearance of oval, spherical, and bounded membrane-enclosed mucus-containing granules in the cytoplasm and on the nucleus together with cytoplasmic swelling and vacuolation; (4) metaplastic hyperplasia of gastric epithelial cells, which was characterized by the coexistence of intestinal metaplastic cells with hyperplastic gastric epithelial cells; (5) atrophic hyperplasia of gastric epithelial cells, which was characterized by the mucosal atrophy accompanied with hyperplasia of gastric pits; (6) low-grade neoplasia of epithelial cells, which was characterized by the mild to moderate dysplasia of gastric epithelial cells; and (7) high-grade neoplasia of epithelial cells, which was characterized by the evident dysplasia of hyperplastic epithelial cells and losses of cell polarity. The different pathological types are associated with different improvement probabilities.

Conclusions

This study demonstrated the histomorphological characteristics and pathological types, which might guide clinicians to track malignant cell transformation, perform precise treatment, predict the clinical prognosis, and control the development of gastric cancer.

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.

Cell polarity (the 'four lines') distinguishes gastric dysplasia from epithelial changes in reactive gastropathy

AIMS

Gastric dysplasia is a risk factor for synchronous and subsequent gastric carcinoma. Distinguishing gastric dysplasia from reactive changes is subject to interobserver disagreement and is a frequent reason for expert consultation. We previously used assessment of surface cell polarity (the 'four lines') as a key feature to decrease equivocal diagnoses in Barrett oesophagus. In the current study, we examined for the presence or absence of the four lines in gastric dysplasia and reactive gastropathy.

MATERIALS AND METHODS

The study includes all (n = 91) in-house biopsies with at least gastric dysplasia from the surgical pathology archives of two academic institutions during a 5-year period from 2008 to 2012. A reactive gastropathy group (n = 60) was created for comparison.

RESULTS

The dysplasia/neoplasia group was comprised of 14 biopsies of gastric foveolar-type dysplasia, 59 of intestinal-type dysplasia, 14 with dysplasia in fundic gland polyps, three pyloric gland adenomas and one oxyntic gland adenoma. Loss of surface cell polarity was seen in all 88 dysplasia cases with evaluable surface epithelium. All 57 reactive gastropathy cases with evaluable surface epithelium showed intact surface cell polarity except in focal areas directly adjacent to erosions in 17 cases, where the thin wisp of residual surface mucin could not be appreciated on haematoxylin and eosin.

CONCLUSION

Surface cell polarity (the four lines) was lost in all gastric dysplasia biopsies with evaluable surface epithelium and maintained in all biopsies of reactive gastropathy. Caution should be taken in using this feature adjacent to erosions in reactive gastropathy.

Comparison of dysplastic fundic gland polyps in patients with and without familial adenomatous polyposis

AIMS

Dysplastic fundic gland polyps (d-FGPs) typically arise in patients with familial adenomatous polyposis (FAP) but may occur in non-syndromic patients. They rarely become malignant, but their significance is unclear, especially in non-syndromic patients. We aimed to compare d-FGPs in patients with and without FAP, using clinicopathologic findings and β-catenin immunohistochemistry (IHC).

METHODS AND RESULTS

We identified 124 fundic gland polyps with low-grade dysplasia (LGD) or high-grade dysplasia (HGD) or indefinite for dysplasia (IFD) from 66 patients (27 with FAP; 39 non-syndromic). We recorded patient sex, age at first d-FGP, time until subsequent d-FGP (if any), history of non-gastric cancer (no patients had gastric cancer), proton-pump inhibitor use, and the presence of Helicobacter pylori. β-Catenin IHC was performed on cases with available blocks. The mean age at d-FGP diagnosis was 31 years for FAP patients and 61 years for non-syndromic patients (P < 0.0001). Sixteen FAP patients (59%) developed at least one subsequent d-FGP, as compared with 10 (27%) non-syndromic patients (P = 0.0099). The median time between d-FGP detection was 11.5 months in FAP patients and 7 months in non-syndromic patients (P = 0.82). Six FAP patients (22%) and 17 non-syndromic patients (44%) had non-gastric malignancies (P = 0.11). β-Catenin IHC showed nuclear positivity in 14 of 112 (13%) d-FGPs: 12 of 94 with LGD, two of three with HGD, and none of 15 with IFD polyps.

CONCLUSIONS

Familial adenomatous polyposis patients develop d-FGPs earlier and more often develop additional ones than non-syndromic patients. d-FGPs in FAP and non-syndromic patients have similar low rates of β-catenin nuclear IHC positivity. FAP and non-syndromic patients developed non-gastric cancers at similar rates, suggesting that d-FGPs may portend a general increased risk of carcinogenesis in non-syndromic patients.

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.

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.

Clinicopathologic Characteristics of Elderly with Gastric Cancer, and the Risk Factors of Postoperative Complications

PURPOSE

In China, gastric cancer (GC), which is one of the most common malignant tumors, has an increasing incidence in elderly population due to aging process. Since a considerable number of elderly patients with GC accepting surgical treatments developed postoperative complications, it is necessary to evaluate risk factors for postoperative complications.

MATERIALS AND METHODS

In the present study, the clinicopathologic characteristics of 3,024 elderly patients (aged ≥65 years) with GC, who underwent surgery between 1996 and 2006, were examined and contributing factors for postoperative complications were analyzed. A total of 2,915 non-elderly patients (aged <65 years) with GC during the same period were enrolled as a control group. Clinicopathologic characteristics of non-elderly patients were investigated and compared with elderly group.

RESULTS

As to clinicopathologic characteristics, significant differences were detected in terms of location of primary lesions between elderly patients and non-elderly patients (p <.05), whereas no statistical difference was observed in other characteristics between two groups (p >.05). Surgical property and method in elderly patients were similar to that in non-elderly patients (p >.05). Regression analysis showed that diabetes, chronic pulmonary disease, preoperative anemia, preoperative hypoalbuminemia, combined organ excision, and blood transfusion were independent factors for complications in elderly patients (p <.05), with some differences from non-elderly group.

CONCLUSIONS

Elderly group with GC had distinctive clinicopathologic characteristics. Surgery remains principal treatment for elderly, and proper preoperative measures are required to decrease postoperative complications.

Barrett's Esophagus: A Comprehensive and Contemporary Review for Pathologists

This review provides a summary of our current understanding of, and the controversies surrounding, the diagnosis, pathogenesis, histopathology, and molecular biology of Barrett's esophagus (BE) and associated neoplasia. BE is defined as columnar metaplasia of the esophagus. There is worldwide controversy regarding the diagnostic criteria of BE, mainly with regard to the requirement to histologically identify goblet cells in biopsies. Patients with BE are at increased risk for adenocarcinoma, which develops in a metaplasia-dysplasia-carcinoma sequence. Surveillance of patients with BE relies heavily on the presence and grade of dysplasia. However, there are significant pathologic limitations and diagnostic variability in evaluating dysplasia, particularly with regard to the more recently recognized unconventional variants. Identification of non-morphology-based biomarkers may help risk stratification of BE patients, and this is a subject of ongoing research. Because of recent achievements in endoscopic therapy, there has been a major shift in the treatment of BE patients with dysplasia or intramucosal cancer away from esophagectomy and toward endoscopic mucosal resection and ablation. The pathologic issues related to treatment and its complications are also discussed in this review article.

Gastric crypt dysplasia: a distinct subtype of gastric dysplasia with characteristic endoscopic features and immunophenotypic and biological anomalies

AIMS

Previous reports have shown that gastric epithelial dysplasia (GED) limited to the crypt (gastric crypt dysplasia, GCD) is commonly identified at the periphery of gastric carcinoma. However, it is unknown whether GCD is endoscopically identifiable, and how it relates to classic GED lesions.

METHODS AND RESULTS

We investigated 1196 consecutive endoscopic resections of GED lesions between January 2011 and December 2014. We also evaluated clinicopathological features of these lesions, as well as the immunohistochemical expression of mucin (Muc)2, Muc5AC, Muc6, CD10, Ki67 and p53. We found 51 (4.3%) lesions composed microscopically of GCD among 1196 GED lesions. Those were elevated mucosal lesions (66.7%) similar in colour and texture to the adjacent mucosa (68.6%). GCD was likely to have an antropyloric location and a higher grade than the adenomatous type, similar to the foveolar and hybrid types (P < 0.05). A gastric immunophenotype was more common in GCD compared to adenomatous GED (P < 0.05). Ki-67- and p53-positive cells were more evident in GCD compared to the adjacent gastric mucosa.

CONCLUSIONS

Our results demonstrated that GCD can be an endoscopically identifiable lesion, sharing many similarities with foveolar and hybrid GED, for which it may represent a precursor lesion in the gastric carcinogenic sequence.

Evidence that gastric pit dysplasia-like atypia is a neoplastic precursor lesion

Most gastric cancers develop via an intestinal metaplasia (IM)-dysplasia-carcinogenic pathway. We have noted that some patients with chronic gastritis have dysplasia-like atypia (DLA) limited to the pit epithelium but without involvement of the surface epithelium. We performed this study to determine the clinical and biological characteristics and outcome of DLA, to gain insight into its role in the pathogenesis of gastric cancer. The study consisted of 102 consecutive patients with resected gastric cancer, a separate cohort of patients (n = 166) with chronic gastritis and IM in their index gastric biopsies, and 44 controls. All specimens were evaluated for clinical and pathologic features of the cancer (in the resection cohort) and background mucosa. Of 102 patients with gastric cancer, 50 (49%) had DLA in areas of mucosa adjacent to or near either conventional dysplasia or cancer. This value was significantly higher than controls (DLA 6.8%; P < .0001). Gastric cancer patients with DLA showed a significantly higher age at presentation; intestinal-type adenocarcinoma; low-grade differentiation; stage 1 tumors; and a higher rate of chronic gastritis, IM, atrophy, and conventional dysplasia in the background mucosa compared to patients without DLA. DLA showed intestinal-type differentiation, and a higher Ki-67 rate and MUC6 positivity compared with IM. Of the 166 patients with biopsies, DLA was identified in 24 (14%). Upon follow-up, 38% of positive cases showed persistent DLA, whereas 25% progressed to conventional low-grade dysplasia. Based on these results, we conclude that DLA represents an important precursor lesion in gastric carcinogenesis and supports its interpretation as a neoplastic lesion.

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.