Sporadic foveolar-type gastric adenoma with a raspberry-like appearance in Helicobacter pylori-naïve patients

Evaluating the detection rate and pathological features of polyps in patients with upper gastrointestinal endoscopy

BACKGROUND

The incidence of gastric polyps (GPs) has ranged from 0.30% to 6.8% in various studies. Most GPs include hyperplastic polyps (HPs), fundic gland polyps (FGPs), and adenomatous polyps (APs). Although APs have a high malignant potential, HPs have a low risk of potential harm, whereas sporadic FGPs have no malignant potential. It is not enough to determine the type and displacement of a polyp by biopsy alone; therefore, some polyps may require an extensive biopsy or complete resection.

AIM

To evaluate the detection rate and pathological features of polyps in patients undergoing upper gastrointestinal endoscopy.

METHODS

This retrospective study included patients with GPs or polyphenic lesions with polyps or malignant histology found in polyps or by gastroscopy at the Department of Gastroenterology at the Shaanxi Provincial Hospital of Traditional Chinese Medicine from 2019 to 2023.

RESULTS

In a series of 10000 patients who underwent upper gastrointestinal endoscopy, 384 (3.84%) had GPs. There were 98 males (25.5%) and 286 females (74.5%). The mean age of patients was 62.8 ± 10.4 (36-75) years. The frequencies of HPs, APs, and FGPs were 88.5%, 5.2%, and 2.1%, respectively. The polyp size of 274 patients (71.3%) was ≤ 1 cm. Polyps were found in 262 cases (68.2%). The most common sites for polyps were the lumen and body of the intestine. Endoscopic polypectomy was performed in 128 patients. Bleeding events were observed and endoscopic treatment was required after endoscopic polypectomy.

CONCLUSION

The incidence of GPs was low. HPs were the most common types of GPs. Of note, as GPs have the potential to develop into adenocarcinoma or precancerous lesions, we suggest that appropriate GP resection technology (e.g., biopsy forceps or mesenchymal resection) be applied.

Multiple metachronous foveolar-type gastric adenomas in a Helicobacter pylori-naïve patient with long-term use of a proton pump inhibitor: a case report

A 69-year-old man undergoing long-term administration of a proton-pump inhibitor (PPI) underwent upper endoscopy, which found a small, whitish, flat lesion in the fundic gland (oxyntic) mucosa. The patient had never received treatment for Helicobacter pylori (Hp) infection, and diagnostic testing for Hp was negative, suggesting an Hp-naïve status. Two years later, the lesion appeared markedly enlarged and was endoscopically resected. Histological examination revealed a low-grade foveolar-type gastric adenoma (FGA), predominantly expressing MUC5AC by immunohistochemistry. Two years later, while PPI therapy was continued, three new flat lesions were found. These were endoscopically resected and histologically diagnosed as low-grade FGAs as before, suggesting that multiple metachronous tumors had developed in a short period of time during long-term PPI administration. A KRAS mutation and a CTNNB1 mutation were identified in the tumor. To our best knowledge, this is the first report of potentially PPI-associated multiple metachronous FGAs in an Hp-naïve patient. Here we report a case of multiple foveolar-type gastric adenomas with rapid metachronous recurrences during long-term use of a proton pump inhibitor in Helicobacter pylori-naïve patient.

Spectrum of gastric neoplasms in Helicobacter pylori-naïve patients

Chronic Helicobacter pylori (Hp) infection is the largest etiological factor for gastric cancer, but in recent years the reports of Hp-naïve gastric neoplasms (HpNGNs) have increased as the Hp-infected population in Japan has been declining. The histopathologic spectrum of HpNGNs differs significantly from that of conventional Hp-infected gastric neoplasms. Molecularly, the former harbor considerably fewer genetic and epigenetic abnormalities, reflecting the absence of chronic inflammatory conditions in the gastric mucosa. The majority of HpNGNs fall within several specific histological entities; each arise from particular background mucosa. Most originate from the fundic gland mucosa and have a gastric immunophenotype, as seen in foveolar-type gastric adenoma (FGA), oxyntic gland adenoma (OGA)/gastric adenocarcinoma of fundic gland type (GA-FG), signet-ring cell carcinoma (SRCC), and sporadic fundic gland polyp with dysplasia (FGPD). In contrast, tumors arising from the pyloric or cardiac gland mucosa have a diverse immunophenotype, as seen in intestinal-type gastric dysplasia (IGD) and gastric cardiac carcinoma. FGA, FGPD, SRCC, and IGD are mostly found as small intramucosal lesions. OGA/GA-FG frequently progresses to invasive carcinoma, but only a few have lymph node metastases. Thus, these tumors are regarded as precancerous lesions by Western pathologists, while in Japan they tend to be diagnosed as carcinomas, even in cases of low-grade dysplasia. Gastric cardiac carcinomas, on the other hand, are often found as advanced carcinomas and harbor a high malignant biological potential. A new diagnostic framework for gastric neoplasms is required in the present era of Hp-naïve individuals in Japan.

Case report: Detection and treatment of a rare submucosal gland duct adenoma of the esophagus

This article reports a rare case of esophageal submucosal gland duct adenoma (ESGDA). The patient was found to have this tumor after undergoing endoscopy in an outpatient clinic due to occasional tingling while eating. White light endoscopy revealed the tumor as a dumbbell-shaped bulge, and ultrasound endoscopy revealed it as a hypoechoic mass located in the submucosal layer. The tumor was successfully resected by endoscopic mucosal dissection with no postoperative recurrence and a good prognosis. In conjunction with literature analysis, the diagnosis of ESGDA relies mainly on endoscopic and pathologic examinations, and its histologic features are highly specific. Despite the rarity of ESGDA, accurate histologic evaluation is essential to avoid misdiagnosis. Complete endoscopic resection is an effective treatment with a favorable long-term prognosis. Further studies remain necessary to reveal its pathogenesis.

Analysis of clinicopathological factors associate with the visibility of early gastric cancer in endoscopic examination and usefulness of linked color imaging: A multicenter prospective study

BACKGROUND

This study investigated clinicopathological factors associated with the visibility of early gastric cancer and the efficacy of linked color imaging.

METHODS

Patients with early gastric cancer who underwent endoscopic treatment between April 2021 and July 2022 were enrolled. All cases underwent white light imaging and linked color imaging. Three experts evaluated lesion visibility using a visual analog scale. A mean score ≥3 on white light imaging was defined as "good visibility", and <3 as "poor visibility". We extracted patient information and endoscopic and pathological data for the lesion and background mucosa, analyzed factors associated with the visibility of early gastric cancer, and compared visibility between white light imaging and linked color imaging.

RESULTS

Ninety-seven lesions were analyzed, with good visibility in 49 and poor visibility in 48. Multivariate analysis revealed small lesion size (odds ratio 1.89) and presence of endoscopic intestinal metaplasia (odds ratio 0.49) as significantly associated with the poor visibility of early gastric cancer. Mean visibility score was significantly higher for linked color imaging (P<0.001). Mean score for linked color imaging was significantly higher in the poor visibility group (P<0.001), but not significantly different in the good visibility group (P = 0.292). Mean score was significantly higher with linked color imaging in cases with endoscopic intestinal metaplasia (P = 0.0496) and lesions <20 mm in diameter (<10 mm, P = 0.002; 10-20 mm, P = 0.004).

CONCLUSIONS

Lesion size and endoscopic intestinal metaplasia are associated with the visibility of early gastric cancer in white light imaging. Linked color imaging improves visibility of gastric cancer with these factors.

Clinicopathologic Features and Outcomes of Endoscopic Submucosal Dissection for Foveolar-Type Adenocarcinoma of the Stomach

PURPOSE

Foveolar-type adenocarcinoma of the stomach is a rare variant of gastric cancer. The clinicopathological features and outcomes of endoscopic submucosal dissection (ESD) for gastric foveolar-type adenocarcinoma remain unclear.

MATERIALS AND METHODS

This study included 1,161 patients who underwent ESD for single early gastric cancers (EGCs) (78 foveolar-type adenocarcinomas and 1,083 well-differentiated [WD] adenocarcinomas). The clinicopathological features and short- and long-term outcomes of ESD for gastric foveolar-type adenocarcinomas were reviewed and compared with those for WD EGCs.

RESULTS

Gastric foveolar-type adenocarcinomas were larger and more likely to exhibit an elevated macroscopic appearance than WD EGCs. Foveolar-type adenocarcinomas exhibited higher rates of lymphatic invasion, histological heterogeneity, and lateral margin involvement than WD EGCs. The en bloc R0 and curative resection rates of foveolar-type adenocarcinoma were 85.9% and 76.9%, respectively. Both foveolar-type adenocarcinoma rates were significantly lower than those of WD EGCs (95.8% and 91.3%, respectively). Lateral margin involvement accounted for 55.6% of the non-curative resection cases of foveolar-type adenocarcinoma. Among patients who underwent curative ESD for foveolar-type adenocarcinoma, no recurrence occurred during the median 62.3 months of follow-up. No lymph node metastases were detected in patients with foveolar-type adenocarcinoma who underwent additional surgery following ESD. The overall and disease-specific survival rates of patients with foveolar-type adenocarcinoma were comparable to those of patients with WD EGC.

CONCLUSIONS

Gastric foveolar-type adenocarcinomas have distinct clinicopathological features among WD EGCs. Given favorable long-term outcomes after curative resection, ESD can be indicated for early gastric foveolar-type adenocarcinomas.

Gastric dysplastic lesions in Helicobacter pylori-naïve stomach: Foveolar-type adenoma and intestinal-type dysplasia

Reports of Helicobacter pylori (Hp)-naïve gastric neoplasm (HpNGN) cases have been rapidly increasing due to the recent increase in the Hp-naïve population in Japan. Most HpNGNs exhibit the gastric immunophenotype and a low malignant potential regardless of histological type. Especially, foveolar-type gastric adenoma (FGA) and intestinal-type gastric dysplasia (IGD) rarely progress to invasive carcinoma. FGA is a foveolar epithelial neoplasm that occurs in the fundic gland (oxyntic gland) mucosa and is classified as the flat type or raspberry type (FGA-RA). The flat type is a large, whitish flatly elevated lesion while FGA-RA is a small reddish polyp. Genomically, the flat type is characterized by APC and KRAS gene mutations and FGA-RA by a common single nucleotide variant in the KLF4 gene. This KLF4 single-nucleotide variant reportedly induces gastric foveolar epithelial tumorigenesis and activates both cell proliferation and apoptosis, leading to its slow-growing nature. IGD consists of an intestinalized epithelial dysplasia that develops in the pyloric gland mucosa, characterized as a superficial depressed lesion surrounded by raised mucosa showing a gastritis-like appearance. Immunohistochemically, it exhibits an intestinal or gastrointestinal phenotype and, frequently, p53 overexpression. Thus, IGD shows unique characteristics in HpNGNs and a potential multistep tumorigenic process.

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.

Clinicopathologic differences of gastric neoplasms between Helicobacter pylori-infected and -naïve patients: a multicenter retrospective analysis

BACKGROUND

The incidence of gastric neoplasms in Helicobacter pylori (Hp)-naïve patients has recently increased due to a remarkable decrease in the Hp-infected population in Japan. We investigated the clinicopathologic differences between Hp-infected gastric neoplasms (HpIGNs) and Hp-naïve gastric neoplasms (HpNGNs) that have not been fully elucidated so far.

METHODS

This retrospective multicenter study investigated 966 consecutive patients with 1131 gastric dysplasia or cancers who underwent endoscopic or surgical treatment for the recent decade. Clinicopathologic features were compared between HpIGN and HpNGN cases.

RESULTS

One thousand and sixty-eight HpIGNs in 916 patients included 877 differentiated types and 191 undifferentiated types. Sixty-three HpNGNs in 50 patients included 57 differentiated types (35 foveolar types, 15 intestinal types, 6 fundic-gland types, and 1 other differentiated type) and 6 undifferentiated types. HpNGNs occurred in younger (59.5 vs. 71.8 years, p < 0.05) and female patients (40.0% vs. 26.5%, p < 0.05), were found more frequently in the proximal compartment (p < 0.05), and had smaller size (median 4.0 vs. 20.0 mm, p < 0.05). Histologically, HpNGNs and HpIGNs both primarily consisted of differentiated type (90.5% vs. 82.1%, p = 0.089) and HpNGNs showed lower prevalence of invasive cancer (11.1% vs. 37.6%, p < 0.05) and lymphovascular invasion (1.6% vs. 31.6%, p < 0.05). Nearly all HpNGNs (62/63, 98.4%) were diagnosed in early pathological stage, while 16.1% (172/1068) of HpIGNs were diagnosed in advanced stage (p < 0.05).

CONCLUSIONS

HpNGNs is recently on the increase but shows lower malignant nature regardless of histologic type than HpIGN. Endoscopic gastric cancer screening will be reviewed via cost effectiveness for Hp-naïve individuals in future.

Endoscopic differential diagnosis between foveolar-type gastric adenoma and gastric hyperplastic polyps in Helicobacter pylori-naïve patients

BACKGROUND

Foveolar-type gastric adenoma (FGA) occurs in Helicobacter pylori (Hp)-naïve individuals and morphologically mimics Hp-naïve gastric hyperplastic polyp (HpN-GHP). FGA is often difficult to distinguish from HpN-GHP even by biopsy, due to its low-grade histologic atypia. We conducted a retrospective study to create an endoscopic diagnostic index.

METHODS

We analyzed 51 FGAs in 41 patients and 36 HpN-GHPs in 24 patients. All lesions were photographed by white-light endoscopy (WLE) and narrow-band imaging with magnification endoscopy (NBIME). Three experts and three non-experts reviewed the WLE and WLE+NBIME images to assess six items for lesion diagnosis. We analyzed correlations between the diagnostic items and histologic features and compared the diagnostic accuracy between modalities. We created a composite diagnostic index and calculated its accuracy and consistency.

RESULTS

FGAs more frequently showed the following features vs. HpN-GHPs: bright-red color (94.1% vs. 44.4%), peripheral hyperplasia (58.8% vs. 8.3%), papillary/gyrus-like microstructure (96.1% vs. 33.3%), visible capillaries (70.6% vs. 38.9%), and demarcation line (98.0% vs. 41.7%) (P < 0.05). White-zone thickening was seen only in HpN-GHPs (52.8%). Diagnostic accuracy (mean, WLE vs. WLE+NBIME) was 90.8 ± 1.1% vs. 93.5 ± 2.4% (P = 0.15) for experts and 88.5 ± 3.0% vs. 86.6 ± 3.5% (P = 0.51) for non-experts. When satisfying the four criteria (bright-red color, papillary/gyrus-like microstructure, demarcation line, and absent white-zone thickening), sensitivity and specificity for FGA were 90.2% and 94.4%, respectively, with a kappa value of ≥ 0.6 for interobserver diagnostic agreement.

CONCLUSIONS

Composite diagnostic index contributes to the reproducible, accurate, preoperative differential diagnosis of FGA and HpN-GHP.

Endoscopic Diagnosis Strategy of Raspberry-Shaped Gastric Lesion in Helicobacter Pylori-Uninfected Patient

OBJECTIVES

We aimed to clarify the endoscopic and clinicopathological features of raspberry-shaped gastric lesions (RSGLs) and to establish an endoscopic diagnostic algorithm for RSGLs.

METHODS

We collected RSGLs from an endoscopic database at our hospital between May 2009 and August 2021. All RSGLs were histopathologically classified and compared based on their endoscopic and clinicopathological characteristics.

RESULTS

Sixty-five RSGLs in 54 patients were classified into five histopathological types: gastric adenocarcinoma of foveolar type (GA-FV, n = 43), gastric adenocarcinoma of fundic-gland type (GA-FG, n = 2), gastric adenocarcinoma of fundic-gland mucosa type (GA-FGM, n = 4), hyperplastic polyp (HP, n = 12), and proton pump inhibitor-related lesion (PPI-L, n = 4). All RSGLs exhibited polygonal or curved marginal crypt epithelium (MCE). GA-FV lesions had homogenously reddish (95%) and an irregular microvascular (MV) pattern (91%). GA-FG lesions were heterogeneously reddish with a submucosal tumor shape (100%) and had a regular MV pattern (50%). GA-FGM lesions were homogen+ously reddish (75%) and occasionally had a submucosal tumor shape (50%) with an irregular MV pattern (75%). HPs and PPI-Ls were homogeneously reddish (93%), with linear or dotted MCE (81%) and a regular MV pattern (100%).

CONCLUSION

Our diagnostic algorithm for RSGLs constructed using endoscopic features might be useful for the endoscopic differential diagnosis of RSGLs.

The features of gastric epithelial reactive hyperplastic lesions under magnifying endoscopy combined with narrow-band imaging

BACKGROUND AND PURPOSE

Gastric reactive hyperplasia (RH) is a common benign lesion of the gastric mucosa that can be resolved by conservative treatment without endoscopic intervention. Some RH lesions are indistinguishable from low-grade intraepithelial neoplasia (LGIN) lesions of gastric mucosa under endoscopy. The aim of this study was to investigate the morphological features of RH lesions under magnifying endoscopy combined with narrow-band imaging (ME-NBI).

METHODS

A retrospective study of 653 patients with superficial suspicious lesions of gastric mucosa was performed. According to the pathological results of biopsies, the final included lesions were divided into the RH group (n = 88) and LGIN group (n = 138). We analysed the microvascular and microsurface patterns of these lesions under ME-NBI, extracted the most significant combination of endoscopic features of RH lesions, and evaluated their diagnostic performance.

RESULTS

ME-NBI characteristics that could distinguish RH lesions from LGIN lesions after univariate analysis were included in multivariate logistic regression. The results showed that ten characteristics, including intervening part (IP) length homogeneity, type III gastric pit pattern and homogeneity of marginal crypt epithelium (MCE), were statistically significant. Receiver operating characteristic (ROC) analysis showed that the triad of these features was the best combination for diagnosing RH lesions with an AUC of 0.886 (95% confidence interval; 0.842-0.929), the sensitivity of 85.5% and specificity of 79.5%.

CONCLUSIONS

The triad of IP length homogeneity, type III pit pattern and MCE homogeneity under ME-NBI helps endoscopists to identify gastric RH lesions, thereby avoiding unnecessary biopsy and repeat endoscopy due to misjudgment of neoplastic lesions.

Randomised clinical trial: 3-year interim analysis results of the VISION trial to evaluate the long-term safety of vonoprazan as maintenance treatment in patients with erosive oesophagitis

BACKGROUND

VISION is a randomised, phase 4, open-label, parallel-group, multicentre study conducted in 33 centres in Japan. The aim of this study was to assess the long-term safety of vonoprazan for maintenance treatment of healed erosive oesophagitis versus lansoprazole.

METHODS

Patients with endoscopically diagnosed erosive oesophagitis were randomised 2:1 to once-daily vonoprazan 20 mg or lansoprazole 30 mg, for a 4- to 8-week healing phase. Patients with endoscopically confirmed healing entered a 260-week maintenance phase with a once-daily starting dose of vonoprazan 10 mg or lansoprazole 15 mg. Primary endpoint was change in gastric mucosal histopathology.

RESULTS

Of 208 patients (vonoprazan, n = 139; lansoprazole, n = 69) entering the healing phase, 202 entered the maintenance phase (vonoprazan, n = 135; lansoprazole, n = 67). At 3 years, 109 vonoprazan-treated and 58 lansoprazole-treated patients remained on treatment. Histopathological evaluation of gastric mucosa showed that hyperplasia of parietal, foveolar and G cells was more common with vonoprazan than lansoprazole at week 156 of the maintenance phase. There was no marked increase in the occurrence of parietal, foveolar and G cell hyperplasia among patients in the vonoprazan group from week 48 to week 156. Histopathological evaluation of the gastric mucosa also showed no neoplastic changes in either group. No new safety issues were identified.

CONCLUSIONS

In this interim analysis of VISION, no new safety concerns were identified in Japanese patients with healed erosive oesophagitis receiving vonoprazan or lansoprazole as maintenance treatment for 3 years. (CT.gov identifier: NCT02679508; JapicCTI-163153; Japan Registry of Clinical Trials: jRCTs031180040).

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.

Confusion and prospects for carcinogenesis of gastric adenoma and dysplasia: What is the correct answer currently?

There are differences in the diagnoses of superficial gastric lesions between Japan and other countries. In Japan, superficial gastric lesions are classified as adenoma or cancer. Conversely, outside Japan, the same lesion is classified as low-grade dysplasia (LGD), high-grade dysplasia, or invasive neoplasia. Gastric carcinogenesis occurs mostly de novo, and the adenoma-carcinoma sequence does not appear to be the main pathway of carcinogenesis. Superficial gastric tumors can be roughly divided into the APC mutation type and the TP53 mutation type, which are mutually exclusive. APC-type tumors have low malignancy and develop into LGD, whereas TP53-type tumors have high malignancy and are considered cancerous even if small. For lesions diagnosed as category 3 or 4 in the Vienna classification, it is desirable to perform complete en bloc resection by endoscopic submucosal dissection followed by staging. If there is lymphovascular or submucosal invasion after mucosal resection, additional surgical treatment of gastrectomy with lymph node dissection is required. In such cases, function-preserving curative gastrectomy guided by sentinel lymph node biopsy may be a good alternative.

KLF4 Mutation Shapes Pathologic Characteristics of Foveolar-Type Gastric Adenoma in Helicobacter pylori-Naive Patients

Along with a recent remarkable decrease in Helicobacter pylori-infected individuals, reports of gastric neoplasms such as sporadic foveolar-type gastric adenoma (FGA) in H. pylori-naive patients have been increasing. This tumor, with its raspberry-like appearance, is common in H. pylori-naive gastric mucosa. The current study investigated the genomic features of sporadic FGA. Fresh-frozen sporadic FGA tissue samples from H. pylori-naive patients were subjected to whole genome analysis using a next-generation sequencer. Proliferation ability and apoptotic profiles of human gastric epithelial cells, along with plasmid transfection of candidate variants, were examined. A mean of 6.65 × 108 total reads were obtained for each sample. Common genetic abnormalities in well-known proliferation driver genes of conventional gastric dysplasia/cancer were not found. However, a common single-nucleotide variation (SNV) was noted within the DNA-binding domain of the tumor suppressor gene KLF4. This novel SNV was located in the zinc finger 2 region. Additional experiments showed that it significantly suppressed proliferation of gastric epithelial cells compared with wild-type KLF4 plasmid-transfected cells, although suppression was reduced in early apoptotic phase-related genes. A novel SNV in the KLF4 zinc finger 2 region was commonly found in sporadic FGA tissue samples, which may explain the slow-growing properties of this neoplasm.

Intestinal-type gastric dysplasia in Helicobacter pylori-naïve patients

Gastric dysplasia and gastric cancer in Helicobacter pylori (Hp)-naïve patients usually exhibit a gastric phenotype, reflecting gastric mucosa without intestinal metaplasia (IM). We showed that intestinal-type gastric dysplasia (IGD) rarely occurs in the Hp-naïve stomach. In the last 10 years, we treated 1760 gastric dysplasia and gastric cancer patients, with 3.6% (63/1760) being Hp-naïve. Among these, ten were diagnosed with 14 IGDs and enrolled in this retrospective analysis. All lesions were observed by white-light endoscopy (WLE) and narrow-band imaging with magnification endoscopy (NBIME). We analyzed their endoscopic and microscopic features and patient demographics. Five men and five women aged 64 ± 21 years were included. WLE showed the depressed lesions mimicking a benign raised erosion in the prepyloric compartment. Multiple growths were confirmed in 30% (3/10) of patients. NBIME showed a near-regular microstructure and capillaries in 50% (7/14) of lesions with a gastritis-like appearance. Histologically, background mucosa was non-atrophic pyloric gland tissue, but 40.0% of samples (4/10) contained sporadic IM. Most of the lesions (8/14) were low-grade dysplasia, and others had a high-grade component, with one progressing to intramucosal carcinoma. The neoplastic surface was widely covered with foveolar epithelium in 57.1% (8/14). Immunohistochemically, neoplastic cells expressed CDX2 in all patients (14/14), MUC2 and CD10 in 92.9% (13/14), MUC5AC in 14% (2/14), and no expression of MUC6, showing an intestinal phenotype. Ki-67 was overexpressed with a mean labeling index of 58.3 ± 38.5%, and p-53 was overexpressed in 92.9% (13/14), regardless of the dysplastic grade. The IGD rarely occurs in Hp-naïve patients with distinctive clinicopathologic characteristics.

The updated WHO classification of digestive system tumours-gastric adenocarcinoma and dysplasia

The fifth edition of the World Health Organization (WHO) classification of digestive system tumours was published in 2019. The classification of invasive carcinoma is basically the same as in the fourth edition, but the description of each histological type has been updated, and some rare subtypes such as micropapillary carcinoma, gastric adenocarcinoma of the fundic gland type and undifferentiated carcinoma have been added and explained. Although this classification did not provide specific numerical criteria for the diagnosis of signet-ring cell carcinoma in poorly cohesive carcinoma, an additional study defined signet-ring cell carcinoma as having more than 90% signet-ring cells. The molecular classification of gastric cancer (Epstein-Barr virus-positive type, microsatellite instability type, genomically stable type, chromosomally unstable type) was additionally introduced. Many pages in the present classification have been devoted to precancerous lesions, and this article focuses on foveolar-type adenoma/dysplasia.