Gastric Adenocarcinoma of the Fundic Gland Type: Update and Literature Review

Fundic gland adenocarcinoma

Gastric malignancy is one of the most common malignancies diagnosed worldwide. Over the past many decades, extensive research has been made into the risk factors, pathogenesis and prognosis of gastric adenocarcinoma. However, gastric adenocarcinoma of the fundic gland (GA-FG) has been recently defined, and not much is known about its risk factors and pathogenesis. Since the first case, which was reported in 2007, only 195 cases have been described in the literature to date. The rarity of the lesion is the cause of unawareness of this entity among reporting pathologists, often leading to its misdiagnosis. Existing literature shows that the risk factors, pathogenesis and even the prognosis of GA-FG are remarkably different from gastric adenocarcinoma. Hence, early and correct diagnosis can have a significant impact on patient management and outcomes.

Mutational Landscape of Gastric Adenocarcinoma of the Fundic Gland Type Revealed by Whole Genome Sequencing

BACKGROUND

Gastric adenocarcinoma of the fundic gland type (GA-FG) is a newly described variant of gastric adenocarcinoma with lack of knowledges regarding its genetic features.

METHODS

We performed whole-genome sequencing (WGS) in formalin-fixed paraffin-embedded (FFPE) tumor tissues and matched adjacent noncancerous specimens from 21 patients with GA-FG, and integrated published datasets from 1105 patients with traditional gastric adenocarcinoma with the purpose of dissecting genetic determinants both common to conventional gastric adenocarcinoma and unique to GA-FG disease.

RESULTS

We characterized the genomic architecture of GA-FG disease, revealing the predominant proportion of C > T substitution among the six types of SNVs. GNAS was the most significantly mutated driver gene (14.29%). 42.8% of samples harbored "Kataegis." Distinct genomic alterations between GA-FG and conventional gastric cancer were identified. Specifically, low mutational burden and relatively moderate mutational frequencies of significantly mutated driver genes, coupled with the absence of non-silent alterations of formerly well-known drivers such as TP53, PIK3CA and KRAS were identified in GA-FG patients. Oncogenic signaling pathway analysis revealed mutational processes associated with focal adhesions and proteoglycans in cancer, highlighting both common and specific procedures during the development of GA-FG and conventional gastric cancer.

CONCLUSION

Our study is the first to comprehensively depict the genomic landscape highlighting the multidimensional perturbations in GA-FG patients. These discoveries offered mechanistic insights for novel diagnostic and therapeutic strategies for patients with such disease.

Oxyntic Gland Neoplasms - From Adenoma to Advanced Gastric Cancer: A Review of 29 Cases

PURPOSE

Oxyntic gland neoplasm (OGN) is a rare condition that can be classified as oxyntic gland adenoma (OGA) or gastric adenocarcinoma of fundic-gland type (GA-FG). GA-FG primarily presents as early gastric cancer, with only a few reported cases of advanced gastric cancer (AGC). We aimed to investigate the clinicopathological features of OGN and describe an aggressive variant.

MATERIALS AND METHODS

We investigated a total of 29 cases, including a patient with double primary cases, diagnosed with OGN or differentiated-type adenocarcinoma with GA-FG morphology, between November 2016 and April 2022. We analyzed 54 pathological specimens and reviewed their clinicopathological, endoscopic, and histological features. The lesions were reclassified as OGA or GA-FG, and immunohistochemical (IHC) staining for MUC-5AC and MUC-6 was performed on available resected GA-FG cases.

RESULTS

The median patient age was 65 years and males accounted for 58.6% of patients. Most cases occurred in the body horizontally (69.0%) and on the greater curvature side cross-sectionally (48.3%). Endoscopically, type 0-IIa (41.4%) and a subepithelial tumor-like appearance (24.1%) were the most common findings. Histologically, there were 8 cases of OGA (27.6%) and 21 cases of GA-FG (72.4%). In GA-FG, MUC-6 was positive in 13 cases (81.3%), whereas MUC-5AC was positive in 8 cases (50.0%). Three cases presented as AGCs.

CONCLUSIONS

Although OGNs are generally considered low-grade, they can present as AGCs and may exhibit features of lymphovascular or perineural invasion. Recognizing the clinicopathological features and accurately diagnosing OGN are important for providing adequate treatment.

Prevalence of Gastric Epithelial Tumors in Helicobacter pylori-uninfected Individuals Undergoing a Medical Checkup

Objective This study investigated the prevalence of gastric epithelial tumor in Helicobacter pylori-uninfected subjects who underwent esophagogastroduodenoscopy (EGD) as part of an annual checkup. Methods A total of 20,540 EGD examinations of H. pylori-uninfected individuals (12,917 men, 7,623 women; mean age 51.5±9.2 years old) were performed between April 2016 and March 2023. The prevalence of gastric epithelial tumor discovery and the size and location of each lesion type were analyzed. Results According to 20,540 examinations, 61 gastric epithelial tumors were endoscopically and histologically diagnosed in 58 of the subjects, with a prevalence rate of 0.28%. These tumors included signet-ring carcinoma (n=10, 0.05%), gastric adenocarcinoma of fundic-gland type (n=10, 0.05%), intestinal-type well-differentiated adenocarcinoma (n=2, 0.01%), and raspberry-type gastric foveolar tumors (n=36, 0.18%). One subject had two intestinal-type well-differentiated adenocarcinomas, and two each had two raspberry-type gastric foveolar tumors. The mean sizes of the signet-ring carcinomas, gastric adenocarcinoma of fundic-gland type, intestinal-type well-differentiated adenocarcinomas, and raspberry-type gastric foveolar tumors were 6.4, 4.7, 5.0, and 3.4 mm, respectively. Each lesion was located at a specific site in the stomach characteristic of its type. Conclusion In the present H. pylori-uninfected subjects, the prevalence of gastric epithelial tumors found on an EGD examination was 0.28%. Endoscopic examination should be performed in H. pylori-uninfected individuals to detect such tumors in characteristic locations.

Antacids and reflux esophagitis as a risk factor for gastric neoplasm of fundic-gland type: A retrospective, matched case-control study

BACKGROUND AND AIM

Since the first report of gastric adenocarcinoma of the fundic-gland type in 2010, the clinicopathological characteristics of gastric neoplasm of the fundic-gland type (GNFG) have become clearer; however, their risk factors remain unclear. This exploratory study aimed to identify the risk factors for GNFG.

METHODS

We conducted a single-center, retrospective, matched case-control study using medical information recorded at our health management center from January 2014 to July 2023. During this period, 39 240 people underwent upper gastrointestinal endoscopy. GNFG were extracted as cases and matched to controls, according to age and sex, in a 1:8 ratio, excluding those with a history of gastrointestinal surgery and those with a history or comorbidity of cancer. Univariate analysis was used to compare patient background and endoscopic findings. Multivariable analysis was performed, adjusting for factors with P values < 0.1 and antacid use.

RESULTS

A total of 20 GNFG cases and 160 matched healthy controls were included. In the univariate analysis, only reflux esophagitis was significantly more common in GNFG (40.0% vs 18.1%; P = 0.036). Factors antacids and duodenitis had P values < 0.1. Logistic regression analysis was performed, adjusting for antacids, reflux esophagitis, and duodenitis. Antacids and reflux esophagitis were the independent risk factors for GNFG (odds ratio = 3.68 [95% confidence interval: 1.04-11.91] and 3.25 [95% confidence interval: 1.11-9.35]).

CONCLUSIONS

Although the sample of patients with GNFG was small, antacids and reflux esophagitis were identified as a risk factor. The pathogenesis of antacids and reflux esophagitis may be involved in the development of GNFG.

Gastric carcinoma of the fundic gland type developed 32 years after Helicobacter pylori eradication for duodenal ulcer: a case report

Introduction

Gastric cancer has been reported to occur with mild to moderate mucosal atrophy, particularly after the eradication of Helicobacter pylori (HP) more than 10 years previously. However, no conclusion has been reached on how many years of esophagogastroduodenoscopy should be performed after HP eradication.

Presentation of case

This was a case of gastric carcinoma of the fundic gland type (GCFGT) 32 years after the eradication of HP, which is the longest posteradication period reported. A 62-year-old male patient was diagnosed with GCFGT after HP eradication and regular esophagogastroduodenoscopy, which revealed a white raised lesion on the anterior wall of the upper part of the body. Endoscopic submucosal dissection was performed for GCFGT, and the vertical and horizontal margins were negative.

Clinical discussion

In this case, HP was eradicated in 1990, and GCFGT developed 32 years later. To the best of our knowledge, this is the longest case in which gastric cancer appeared after HP eradication. HP eradication therapy for a duodenal ulcer was first reported in 1990, supporting that this is the longest case.

Conclusions

This is the first case of gastric cancer more than 20 years after the eradication of HP. The endoscopic findings of this case are typical of GCFGT and may be useful when encountering such cases in the future. Therefore, the risk of gastric cancer should be considered for an extended period even after the eradication of HP, and regular esophagogastroduodenoscopy is recommended even after the eradication of HP.

The white ring sign is useful for differentiating between fundic gland polyps and gastric adenocarcinoma of the fundic gland type

Background and study aims Gastric adenocarcinoma of the fundic gland type (GA-FG) is characterized by an elevated lesion with vessel dilation exhibiting branching architecture (DVBA). However, this feature is also found in fundic gland polyps (FGPs), posing a challenge in their differentiation. In this study, we aimed to investigate the clinicopathological features of gastric elevated lesions with DVBA and assess the efficacy of the white ring sign (WRS) as a novel marker for distinguishing between FGPs and GA-FGs. Methods We analyzed 159 gastric elevated lesions without DVBA and 51 gastric elevated lesions with DVBA, further dividing the latter into 39 in the WRS-positive group and 12 in the WRS-negative group. The clinicopathological features, diagnostic accuracy, and inter-rater reliability were analyzed. Results Univariate and multivariate analyses for gastric elevated lesions with DVBA identified the histological type consistent with FGPs and GA-FGs, along with the presence of round pits in the background gastric mucosa, as independent predictors. FGPs were present in 92.3% (36/39) of the WRS-positive group and GA-FGs were observed in 50.0% (6/12) of the WRS-negative group. WRS positivity and negativity exhibited high diagnostic accuracy, with 100% sensitivity, 80.0% specificity, and 94.1% accuracy for FGPs, and 100% sensitivity, 86.7% specificity, and 88.2% accuracy for GA-FGs. Kappa values for WRS between experts and nonexperts were 0.891 and 0.841, respectively, indicating excellent agreement. Conclusions WRS positivity and negativity demonstrate high diagnostic accuracy and inter-rater reliability for FGPs and GA-FGs, respectively, suggesting that WRS is a useful novel marker for distinguishing between FGPs and GA-FGs.

Prevalence, clinical characteristics and treatment outcomes of oxyntic gland neoplasm: a single-center retrospective study

BACKGROUND

Oxyntic gland neoplasm (OGN) is a rare subtype of gastric cancer. The aim of this study is to evaluate the prevalence, clinicopathological features, effectiveness and safety of endoscopic treatment, as well as the prognosis of OGN.

METHODS

We retrospectively analyzed the data of patients pathologically diagnosed with OGN at our hospital from November 1, 2019 to May 1, 2023.

RESULTS

A total of 36 patients with 45 lesions were identified, resulting in a disease frequency of 0.047% (36/76,832). The mean age was 55.0 ± 7.5 years, with a male-to-female ratio of about 1:1.12. Most lesions were ≤10 mm in size (84.4%), located in the upper third of the stomach (73.3%), exhibited slight elevation (75.5%), appeared whitish (55%), had dilated blood vessels on the surface (75.5%). 16 and 21 lesions were treated by precutting endoscopic mucosal resection (EMR-P) and endoscopic submucosal dissection (ESD), respectively. No significant differences were found between EMR-P and ESD in terms of en bloc resection rate (100% vs 100%, p = 1.000), complete resection rate (100% vs 90.5%, p = 0.495), and curative resection rate (93.8% vs 90.5%, p = 1.000). No complications such as bleeding and perforation were observed. No recurrence or metastasis was observed during the follow-up period.

CONCLUSIONS

OGN is a rare tumor with unique clinical, endoscopic, and pathological characteristics. EMR-P and ESD are deemed safe and effective for treating OGNs. The relatively faster and easier EMR-P seems at least non-inferior to ESD, especially for removal of smaller OGNs. The overall prognosis is favorable.

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.

Curative endoscopic full-thickness resection of a fundic gland-type gastric adenocarcinoma

Video 1Summary of the presented case. Macroscopic images of the lesion in a white-light endoscopy and narrow-band imaging and in an underwater view followed by scenes from the resection with circular marking, submucosal injection, circumferential incision, and submucosal dissection using a multi-bend double-channel endoscope, as well as clip traction, controlled full-thickness dissection, and inspection of the defect plus closure of the defect with the clip-and-loop technique.

A puzzling case report of well-differentiated neuroendocrine tumor mixed with gastric adenocarcinoma of the fundic gland type associated with autoimmune gastritis

Gastric adenocarcinoma of the fundic gland type (GA-FG) is a rare gastric neoplasm. We present a unique case of multiple GA-FG that coexisted with the well-differentiated neuroendocrine tumors in a patient with autoimmune gastritis. To our knowledge, this is the first documented instance of such a co-occurrence and the molecular mechanism of their origin has been reviewed systematically. A 47-year-old male presented to our hospital with abdominal distension for over 10 years. Gastroscopy revealed multiple gastric eminence lesions (0.2-1.5 cm). After endoscopic mucosal resection, the pathological morphology showed mixed tumor components infiltrating into the submucosa with puzzling similarity. One with uniform-sized tumor cells arranged in nests or tubes and the other a well-differentiated tubular adenocarcinoma with irregular branching and visible gland fusion. Immunohistochemistry findings revealed the first component expressed typical markers of neuroendocrine tumor, whereas the second component expressed pepsinogen and mucin-6, indicating the presence of oxyntic gland adenocarcinoma. Due to the tumors' proximity to the surgical margins, the patient underwent laparoscopic subtotal gastrectomy three months after the diagnosis without any tumor residue and showed no recurrence or metastasis occurred in the following regular checkups.

Unusual or Uncommon Histology of Gastric Cancer

This review comprehensively examines the diverse spectrum of gastric cancers, focusing on unusual or uncommon histology that presents significant diagnostic and therapeutic challenges. While the predominant form, tubular adenocarcinoma, is well-characterized, this review focuses on lesser-known variants, including papillary adenocarcinoma, micropapillary carcinoma, adenosquamous carcinoma, squamous cell carcinoma (SCC), hepatoid adenocarcinoma, gastric choriocarcinoma, gastric carcinoma with lymphoid stroma, carcinosarcoma, gastroblastoma, parietal cell carcinoma, oncocytic adenocarcinoma, Paneth cell carcinoma, gastric adenocarcinoma of the fundic gland type, undifferentiated carcinoma, and extremely well-differentiated adenocarcinoma. Although these diseases have different nomenclatures characterized by distinct histopathological features, these phenotypes often overlap, making it difficult to draw clear boundaries. Furthermore, the number of cases was limited, and the unique histopathological nature and potential pathogenic mechanisms were not well defined. This review highlights the importance of understanding these rare variants for accurate diagnosis, effective treatment planning, and improving patient outcomes. This review emphasizes the need for ongoing research and case studies to enhance our knowledge of these uncommon forms of gastric cancer, which will ultimately contribute to more effective treatments and better prognostic assessments. This review aimed to broaden the pathological narrative by acknowledging and addressing the intricacies of all cancer types, regardless of their rarity, to advance patient care and improve prognosis.

Prevalence of Raspberry-type Gastric Foveolar-type Tumor in Individuals Undergoing Medical Checkups

Objective This study was performed to clarify the prevalence of raspberry-type gastric foveolar-type tumors, along with the time-course changes in the size and clinical course. Methods The subjects were 10,663 consecutive patients who underwent a medical checkup between April 2016 and March 2022, including an esophagogastroduodenoscopy (EGD) examination and determination of Helicobacter pylori infection status (uninfected, positive, post-eradication). The presence of characteristic reddish polypoid lesions in the stomach was investigated, and a diagnosis of raspberry-type gastric foveolar-type tumor was made based on histological findings. Results Thirty-eight cases had gastric polyps with a raspberry-like appearance on endoscopy, with 29 lesions in 28 cases endoscopically and histologically diagnosed as a raspberry-type gastric foveolar-type tumor. All of the affected subjects were determined to be H. pylori-uninfected. The prevalence of this type of lesion in all subjects was 0.26%, while that in the 6,635 H. pylori-uninfected subjects was 0.42%. An older age and the presence of a fundic gland polyp were found to be significant risk factors associated with the occurrence of the tumor. The mean size was 3.8±1.9 (range: 2-10) mm, and the location was in a fundic gland area in all affected subjects. Furthermore, examinations of previous EGD images revealed that two-thirds of the lesions had not changed in size, while follow-up EGD findings showed that lesions ≤5 mm in size had disappeared after a biopsy procedure. Conclusion The prevalence of raspberry-type gastric foveolar-type tumors was 0.42% in H. pylori-uninfected subjects. More than half of the lesions were too small to be removed by an endoscopic biopsy.

Clinicopathological Features and the Prevalence of Oxyntic Gland Neoplasm: A Single-center Retrospective Study

Objective We explored the clinicopathological characteristics and disease frequency of oxyntic gland neoplasms (OGNs). Methods We retrospectively evaluated the data of patients pathologically diagnosed with OGN at an internal medicine clinic. Patients A total of 13,240 upper gastrointestinal endoscopies were performed on 7,488 patients between December 1, 2017, and March 31, 2021. Results We identified 27 patients with 30 histopathologically confirmed OGNs, yielding a disease frequency of 0.36% (27/7,488). Furthermore, multiple simultaneous lesions were found in 3 of 27 patients (11%). One (3.3%) of the 30 lesions was present in the antrum, whereas the remaining lesions occurred in the body of the stomach. Nine (33%) of the 27 patients had no history of Helicobacter pylori infection, whereas the remaining 18 (67%) were either currently or had been previously infected. Nevertheless, 27/30 lesions (90%) still occurred in non-atrophied regions. After endoscopic treatment, a histopathological examination of the resected specimens revealed submucosal infiltration in 8 (44%) of the 18 lesions; however, none of the lesions showed submucosal desmoplasia. For all patients with submucosal involvement, only observation was performed. There were no recurrent lesions found on follow-up. Conclusion The period prevalence of OGN was 0.36%, which is much higher than previously reported. The discovery of a small submucosal appearing lesion with a faded yellow or white color and dilated microvasculature, especially in a non-atrophic area of the stomach, should raise suspicion for an OGN, which can be endoscopically managed.

Oxyntic Gland Adenoma in a Patient With Refractory Reflux

A 58-year-old African American male was referred for endoscopic evaluation due to a persistent nine-year history of reflux. Previous endoscopy nine years ago revealed a small hiatal hernia and chronic gastritis caused by Helicobacter pylori (H. pylori), which was treated with triple therapy. During the current endoscopic evaluation, findings consistent with reflux esophagitis were identified, along with the discovery of an incidental 6 mm sessile polyp in the gastric fundus. Pathological examination revealed the presence of an oxyntic gland adenoma (OGA). Otherwise, the stomach was found to be unremarkable endoscopically and histologically. OGA is a rare gastric neoplasm that is primarily observed in Japan, with very few reported cases in North America. Studies have suggested a potential association with antacids, while the role of H. pylori in the development of OGA remains controversial. Our patient's OGA was completely resected during the endoscopy, with no recurrence noted on the three-month follow-up.

[Clinicopathological features of Helicobacter pylori-negative early gastric cancer]

OBJECTIVE

To investigate the clinicopathological features of Helicobacter pylori (Hp)-negative early gastric cancer.

METHODS

The clinicopathological data of 30 cases of Hp-negative early gastric cancer were collected retrospectively at Pingdingshan Medical District, 989 Hospital of PLA Joint Logistics Support Force, and Beijing Chaoyang Hospital, Capital Medical University, from 2009 to 2021, and the histomorphological characteristics and immunophenotype were observed, and combined with the literature to explore.

RESULTS

The median age of 30 patients was 58.5 years (range: 21-80 years), including 13 males and 17 females. The upper part of the stomach was 13 cases, the middle part of the sto-mach was 9 cases, and the lower part of the stomach was 8 cases. The median diameter of the tumor was 11 mm (range: 1-30 mm). According to the Paris classification, 9 cases were 0-Ⅱa, 7 cases were 0-Ⅱb, and 14 cases were 0-Ⅱc. Endoscopic examination showed that 18 cases of lesions were red, 12 cases of lesions were faded or white, and microvascular structures and microsurface structures were abnormal. In all the cases, collecting venules were regularly arranged in the gastric body and corner mucosa. There were 18 cases of well differentiated adenocarcinoma in the mucosa. The tumor presented glandular tubular-like and papillary structure, with dense glands and disordered arrangement; the cells were cuboidal or columnar, with increased nuclear chromatin and loss of nuclear polarity, and most of them expressed gastric mucin. Signet-ring cell carcinoma was found in 7 cases, all the cancer tissues were composed of signet-ring cells, and the cancer cells were mainly distributed in the middle layer to the surface layer of mucosa. Gastric oxyntic gland adenoma (gastric adenocarcinoma of the fundic gland type confined to mucosa) in 2 cases, gastric adenocarcinoma of the fundic gland type in 2 cases, and gastric adenocarcinoma of fundic gland mucosa type in 1 case. The tumor tissue was composed of branching tubular glands, except 1 case of mucosal surface epithelium was partially neoplastic, the other 4 cases of mucosal surface epi-thelium were all non-neoplastic; the cells were arranged in a single layer, and the nucleus was close to the basal side, and the nucleus was only slightly atypical. Pepsinogen I and H+/K+ ATPase were positive in 5 cases of gastric fundus gland type tumors, and 1 case of foveolar-type tumor cells at the surface and depth of mucosa showed MUC5AC positive. The gastric mucosa adjacent to cancer was generally normal in all cases, without atrophy, intestinal metaplasia and Hp.

CONCLUSION

Hp-negative early gastric cancer is a heterogeneous disease group with various histological types, and tubular adenocarcinoma and signet-ring cell carcinoma are common. Tubular adenocarcinoma mostly occurs in the elderly and the upper to middle part of the stomach, while signet-ring cell carcinoma mostly occurs in young and middle-aged people and the lower part of the stomach. Gastric neoplasm of the fundic gland type is relatively rare.

Preoperative endoscopy and pathology report of the specimen to be recommended in sleeve gastrectomy?

Objective

Preoperative upper gastrointestinal endoscopy (UGIE) and postoperative histopathological examination (HPE) of resected specimens are still controversial issues in bariatric surgery.

Methods

A retrospective review of prospectively collected laparoscopic sleeve gastrectomies (SG) performed at our institution for morbid obesity was carried out. All patients underwent pre-operative UGIE with biopsy, post-operative HPE and conventional post-operative follow-up.

Results

From January 2019 through January 2021 we performed a total of 501 laparoscopic SG. A total of 12 (2.4%) neoplasms were found, 2 evident at preoperative UGIE, 4 detected during operation, and 6 at HPE. Eight of these 12 cases had some malignant potential and 5 would not have been detected without HPE of the specimen. The most significant unexpected case was a fundic gland type adenocarcinoma in a 64-year-old female with severe obesity.

Conclusion

On the basis of our clinical experience, we recommend both preoperative endoscopic assessment and postoperative HPE of the specimen to provide the best available treatment to these patients.

Clinicopathological features of gastric adenocarcinoma of fundic gland type

BACKGROUND

Gastric adenocarcinoma of fundic gland type (GA-FG) is a newly discovered type of gastric cancer in recent years, and it is a form of well-differentiated malignancy unlike conventional intestinal and diffuse gastric cancers. It is expected that GA-FG will account for an increasing proportion of all gastric cancers, but the current lack of knowledge among endoscopists and clinicopathologists may lead to misdiagnosis.

AIM

To increase the diagnostic yield of GA-FG and reduce missed diagnosis and misdiagnosis, we conducted a systematic review of the endoscopic, clinical, and pathological features of GA-FG.

METHODS

The clinical, pathological, and endoscopic data of patients with GA-FG reported in the Chinese and English literature published between January 2007 and March 2022 were collected from PubMed and CNKI and retrospectively analyzed.

RESULTS

Data related to a total of 322 lesions in 320 patients with GA-FG were collected from 67 articles. Most of the lesions were located in the upper third of the stomach (81.6%), with an average lesion size of 9.66 mm (1 mm-85 mm), and approximately 76.88% of the lesions had an elevated gross morphology. Microvascular dilatation and disorganized or thickened microglandular structures were observed on the surface of the lesions by narrow band imaging. The main cell differentiation type accounted for approximately 74.84% of all lesions, which significantly expressed MUC6 and pepsinogen.

CONCLUSION

The incidence of GA-FG is low. Endoscopic complete resection and surgical operation can achieve curative resection. The prognosis is good, but it tends to be misdiagnosed. The diagnosis should be combined with its clinicopathological characteristics to reduce the rate of misdiagnosis and missed diagnosis.

Twenty cases of gastric adenocarcinoma of the fundic gland type

BACKGROUND

Gastric adenocarcinoma of the fundic gland type is a new subtype of gastric adenocarcinoma. In 2019, the World Health Organization (WHO) listed gastric adenocarcinoma of the fundic gland type (GA-FG) as a new and rare gastric tumour with a low incidence due to the small number of cumulative cases worldwide. Twenty cases of GA-FG found in our centre were retrospectively analysed to improve the diagnostic ability of endoscopy and pathology in this disease.

OBJECTIVE

To investigate the clinicopathological features of fundus-derived gastric tumours and to improve the understanding of and diagnostic accuracy of endoscopy for this disease.

METHODS

The clinicopathological characteristics of 20 GA-FG cases between 2018 and 2022 were analysed using clinical and follow-up data and endoscopic, immunohistochemical, and pathological morphology characteristics.

RESULTS

In all cases, GA-FG was found in the fundus and the body of the stomach. In total, there were 19 patients with 20 lesions, with most of the patients having a single lesion. One patient had multiple lesions, and another patient had complications from signet ring cell carcinoma (SRCC). All lesions occurred in non-atrophic areas, and 10 patients had gastric fundic gland polyps simultaneously. There were 14 cases of gastric fundus adenocarcinoma and 6 cases of acid-secreting adenoma. Fourteen lesions were treated with endoscopic submucosal dissection (ESD), without recurrence or metastasis during the follow up; 6 patients were followed up for observation, 2 of whom showed no lesions after the first biopsy by gastric endoscopy, and 4 of whom showed no significant changes.

CONCLUSIONS

The incidence rate for GA-FG lesions may be underestimated due to their benign course. ESD seems to be an adequate treatment for GA-FG.

MAIN POINTS

Gastric adenocarcinoma of the fundic gland type (GA-FG) is located in the fundus and body of the stomach. All lesions occur in non-atrophic areas, and almost one-half involve gastric fundus polyps simultaneously. GA-FG lesions typically follow a benign disease course. ESD seems to be an adequate treatment for GA-FG.

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.

Transcriptome analysis reveals the essential role of NK2 homeobox 1/thyroid transcription factor 1 (NKX2-1/TTF-1) in gastric adenocarcinoma of fundic-gland type

BACKGROUND

Gastric adenocarcinoma of fundic-gland type (GA-FG) is a gastric malignancy with little relation to Helicobacter pylori. Clinical characteristics of GA-FG have been established, but molecular mechanisms leading to tumorigenesis have not yet been elucidated.

METHODS

We subjected three GA-FG tumors-normal mucosa pairs to microarray analysis. Network analysis was performed for the top 30 up-regulated gene transcripts, followed by immunohistochemical staining to confirm the gene expression analysis results. AGS and NUGC4 cells were transfected with the gene-encoding NK2 homeobox 1/thyroid transcription factor 1 (NKX2-1/TTF-1) to evaluate transcriptional changes in its target genes.

RESULTS

Comprehensive gene expression analysis identified 1410 up-regulated and 1395 down-regulated gene probes with ≥ two-fold difference in expression. Among the top 30 up-regulated genes in GA-FG, we identified transcription factor NKX2-1/TTF-1, a master regulator of lung/thyroid differentiation, together with surfactant protein B (SFTPB), SFTPC, and secretoglobin family 3A member 2(SCGB3A2), which are regulated by NKX2-1/TTF-1. Immunohistochemical analysis of 16 GA-FG specimens demonstrated significantly higher NKX2-1/TTF-1 and SFTPB levels, as compared to that in adjacent normal mucosa (P < 0.05), while SCGB3A2 levels did not differ (P = 0.341). Transduction of NKX2-1/TTF-1 into AGS and NUGC4 cells induced transactivation of SFTPB and SFTPC, indicating that NKX2-1/TTF-1 can function as normally in gastric cells as it can in the lung cells.

CONCLUSIONS

Our first transcriptome analysis of GA-FG indicates significant expression of NKX2-1/TTF1 in GA-FG. Immunohistochemistry and cell biology show ectopic expression and normal transactivation ability of NKX2-1/TTF-1, suggesting that it plays an essential role in GA-FG development.

Endoscopic submucosal dissection for gastric adenocarcinoma of the fundic gland type (chief cell predominate type): Four years' experience from a tertiary hospital

OBJECTIVE

To summarize the endoscopic and clinicopathological features of gastric adenocarcinoma of the fundic gland type (GA-FG), and to evaluate the efficacy and safety of endoscopic submucosal dissection (ESD) for the treatment of GA-FGs.

METHODS

From September 2017 to August 2021, patients treated with ESD who were pathologically confirmed to have GA-FGs were included. Those with lymphovascular and distal metastasis were excluded before ESD. The medical records were retrospectively reviewed to obtain information regarding patient demographics, clinicopathological characteristics, tumor features, complete resection rate, and complications, etc. All patients underwent follow-up for at least 12 months to evaluate any local recurrence or distant metastasis.

RESULTS

A total of 15 patients with an average age of 56.9 ± 10.7 years were recruited, including 11 men and 4 women. Lesions were found at the upper third (13 [86.7%]) or middle third (2 [13.3%]) of the stomach. The average lesion size was 9.1 ± 4.8 mm. Macroscopically, lesions presented as a flat elevated type with reddish or erosion on top (n = 7, 46.7%), depressed type with pale color (n = 5, 33.3%), or submucosal tumor (SMT)-like appearance type (n = 3, 20.0%). En bloc resection, complete resection and curative resection were achieved in 14 (93.3%), 13 (86.7%), and 11 (73.3%) patients, respectively. Nine (60.0%) of the lesions had submucosal invasion. One patient underwent additional surgery. No local recurrence or metastasis was detected during the follow-up duration.

CONCLUSIONS

GA-FGs present with various endoscopic features. ESD appears to be effective and safe for treating early-stage GA-FGs.

Clinicopathological and molecular characterization of early gastric adenocarcinoma in Helicobacter pylori-uninfected patients: emphasis on differentiated gastric adenocarcinoma

BACKGROUND

Recently, Helicobacter pylori (HP)-uninfected gastric mucosal cancer has been reported; however, the clinicopathological and molecular features of HP-uninfected gastric cancer have not been elucidated.

METHODS

We evaluated the clinicopathological, immunohistochemical, and genetic alterations in HP-uninfected early gastric adenocarcinoma using next-generation sequencing (NGS).

RESULTS

Among 968 primary early gastric carcinomas, 64 (6.6%) were HP-uninfected gastric adenocarcinoma and were pathologically classified as gastric adenocarcinoma of fundic-gland type (GA-FG, n = 39), differentiated gastric adenocarcinoma (DGA, n = 16), and signet-ring cell carcinoma (SRCC, n = 9). Based on the expression profile of the mucin core protein, DGAs were classified into a gastrointestinal phenotype showing either MUC5AC or MUC6 expression and MUC2 or CD10 expression simultaneously (n = 5), and a gastric phenotype (n = 11) showing either MUC5AC or MUC6 expression. All DGAs with a gastrointestinal phenotype shared similar endoscopic characteristics, such as reddish depressed lesions in the antrum. In contrast, DGAs with a gastric phenotype exhibited several distinct endoscopic features, including a raspberry-shaped appearance and whitish flat-elevated appearance; the former expressed only MUC5AC and the latter exhibited co-expression of MUC5AC and MUC6. Among 16 HP-uninfected DGAs, seven were subjected to NGS. APC was recurrently mutated in DGA (42.9%) and was enriched in DGAs with a gastrointestinal phenotype (75%).

CONCLUSIONS

Overall, HP-uninfected gastric adenocarcinomas showed distinct clinicopathologic and endoscopic characteristics. Furthermore, HP-uninfected DGAs, especially those with a gastrointestinal phenotype, may be characterized by recurrent APC mutations.

Clinicopathological characteristics of signet-ring cell carcinoma derived from gastric fovelar epithelium

OBJECTIVE

We aimed to investigate the immunophenotype, differential diagnosis, and clinicopathological characteristics of signet-ring cell carcinoma (SRCC) derived from gastric foveolar epithelium.

METHODS

Clinical characteristics, endoscopic findings, histopathological features, and follow-up data of seven cases of SRCC derived from gastric foveolar epithelium with small intramucosal lesions were analyzed.

RESULTS

Seven patients with a mean age of 38.3 years were diagnosed with SRCC derived from gastric foveolar epithelium and small intramucosal lesions, all of them were negative for CDH-1 germline mutation. The glands proliferated and expanded, and then morphologically transformed into signet-ring cells and formed clonal hyperplastic SRCC, which expanded laterally along the gastric foveolar cells to a length of 3-6 mm. Periodic acid Schiff staining was positive, while CK7 and MUC6 were negative, in all cases. Ki-67-positive cells ranged 37%-60%. During a follow-up period of 6-30 months, no patients experienced tumor recurrence or metastasis.

CONCLUSIONS

SRCC derived from gastric foveolar epithelium is originated from the proliferative region of the bottom of the gastric pit and gland neck. It is easily missed diagnosed or misdiagnosed as it grows laterally along the gastric foveolar cells. Biological behavior, genetics, and etiology of such SRCC, as well as the clinicopathological characteristics, need to be further studied.

Endoscopic features of oxyntic gland adenoma and gastric adenocarcinoma of the fundic gland type differ between patients with and without Helicobacter pylori infection: a retrospective observational study

BACKGROUND

The endoscopic features of oxyntic gland adenoma and gastric adenocarcinoma of the fundic gland type have not been fully investigated in relation to Helicobacter pylori infection status. We compared the morphology, color, and location of these lesions between patients with and without H. pylori infection.

METHODS

We retrospectively enrolled 165 patients (180 lesions) from 10 institutions. We divided the patients into the (i) Hp group (patients with current H. pylori infection [active gastritis, n = 13] and those with past infection [inactive gastritis, n = 76]) and (ii) uninfected group (H. pylori-uninfected patients, n = 52). We compared the clinical and endoscopic features of the two groups. We also performed an analysis between (i) lesions with atrophy of the surrounding gastric mucosa (atrophy group) and (ii) lesions without atrophy of the surrounding gastric mucosa (non-atrophy group).

RESULTS

The average age was older in the Hp group than in the uninfected group (68.1 ± 8.1 vs. 63.4 ± 8.7 years, p < 0.01). Although the difference was not statistically significant (p = 0.09), multiple lesions were observed in 9 of 89 patients (10.1%) in the Hp group and in only 1 of 52 patients (1.9%) in the uninfected group. Meanwhile, significant differences were observed in the prevalence of lesions located in the gastric fornix or cardia (uninfected group: 67.3% vs. Hp group: 38.0%, p < 0.01), with an elevated morphology (80.0% vs. 56.0%, p < 0.01), with a subepithelial-like appearance (78.2% vs. 42.0%, p < 0.01), and with a color similar to that of the peripheral mucosa (43.6% vs. 25.0%, p = 0.02). The male-to-female ratio, lesion size, and presence or absence of vascular dilatation or black pigmentation on the surface were not different between the two groups. In the analysis comparing lesions with and without mucosal atrophy, the prevalence of multiple lesions was significantly higher (p = 0.02) in the atrophy group (5/25 patients, 20.0%) than in the non-atrophy group (7/141 patients, 5.0%).

CONCLUSIONS

The endoscopic features of oxyntic gland adenoma and gastric adenocarcinoma of the fundic gland type differ between patients with and without H. pylori infection.

SP70 is a potential biomarker to identify gastric fundic gland neoplasms

Background

Gastric neoplasms with fundic gland differentiation include oxyntic gland adenomas (OGAs) and gastric adenocarcinomas of fundic gland type (GA-FGs). Due to their well-differentiated and similar morphology with normal fundic glands, it is usually challenging to identify these lesions in pathological diagnosis, especially in biopsy specimens. This study aims to explore and verify the potential role of a newly developed monoclonal antibody (McAb) NJ001 (SP70) in differentiating fundic neoplasms from non-neoplastic fundic gland lesions.

Methods

Twenty-three cases of histological confirmed gastric fundic gland neoplasms were obtained, including 12 cases of OGAs and 11 of GA-FGs. Fifty cases of fundic gland polyps (FGPs) were taken as the control group. Six cases of well-differentiated gastric neuroendocrine tumors (NETs) (easily misdiagnosed) were also obtained. Key clinicopathological information was collected. SP70 immunostaining was performed (with para-tumor normal fundic glands as internal control). The positive intensity and staining pattern of SP70 were analyzed and compared.

Results

In normal gastric mucosa, SP70 was strongly and diffusely stained on the cytoplasm in fundic glands, but not in the foveolar epithelium. Therefore, a zonal distribution of SP70 was observed in normal mucosa. FGPs (50/50, 100%) shared a similar expression pattern with normal fundic glands. In fundic gland neoplasms, a significant down-expression of SP70 was observed in both OGAs and GA-FGs. The positive rate of SP70 in fundic gland neoplasms (6/23, 26.1%) was significantly lower than that in FGPs (100%) (P<0.0001). There was no difference in SP70 expression between OGAs (3/12, 25.0%) and GA-FGs (3/11, 27.2%) group (P>0.05). In these 6 NET cases, SP70 was weak to moderate intensity in the majority of tumor cells (with a different expression pattern).

Conclusion

Down-expression of SP70 is a specific feature to fundic gland neoplasms including OGAs and GA-FGs. Therefore, SP70 can serve as a potential biomarker in the identification and differential diagnosis of fundic gland neoplasms.

Pepsinogen I- and H+/K+-ATPase-immunohistochemical Positivity in Endoscopically Resected Early Gastric Neoplasia

Gastric adenocarcinoma of the fundic gland type (GAFG) has been recently classified by the World Health Organization (WHO), however, clinicopathologic features of pepsinogen I- or H+/K+-ATPase-positive gastric tumors remain unclear. Therefore, this study evaluates the frequency and clinicopathologic features of those tumors, using a tissue microarray block to identify pepsinogen I- or H+/K+-ATPase-positive tumors from 810 endoscopically resected, early gastric epithelial tumors. The frequency of pepsinogen I-positive lesions was 2.1%, and that of H+/K+-ATPase-positive lesions was 2.0%. Pepsinogen I- or H+/K+-ATPase positivity was not observed in undifferentiated-type tumors, while gastric tumors with morphologic similarity to fundic glands were positive for pepsinogen I- or H+/K+-ATPase. We divided pepsinogen I- or H+/K+-ATPase-positive gastric tumors into group A, with fundic gland-like structure, or group B, without fundic gland-like structure. The frequency of group A was 1.6%: 46.2% were positive only for pepsinogen I and 53.8% for H+/K+-ATPase and pepsinogen I. The frequency of group B was 1.5%: 25% were positive only for pepsinogen I, 8.3% for H+/K+-ATPase and pepsinogen I, and 66.7% only for H+/K+-ATPase. The 2 tumor groups differed in location and endoscopic features. Hematoxylin and eosin staining showed that group B had more exposed tumors to the surface, larger nuclei, and more background atrophy than group A. Immunostaining showed significantly higher positivity rates for MUC5AC, CD10, CDX2, and p53 expression, and a higher Ki-67 labeling score. Our results provide novel insights into the pathology of early gastric tumors with histologic or immunohistochemical evidence of fundic gland differentiation.

Clinicopathological features of early stage gastric adenocarcinoma of fundic gland type: Case series

INTRODUCTION

Gastric adenocarcinoma of the fundic gland type (GA-FG) is characterized by a well-differentiated neoplasm. More than 100 cases have been reported, but only a few cases have been described in China. Therefore, its clinicopathological characteristics need to be investigated further. Herein, we report five cases and briefly review the relevant literature.

PATIENT CONCERNS

Five patients, including three women and two men, were identified in the Ningbo Clinical Pathological Diagnosis Center between March 2017 and July 2020. Patients (case 1, case 2, and case 5) underwent gastroscopy due to epigastric pain. Apart from the lesion, others were occasionally discovered on physical examination.

DIAGNOSIS

Gastric adenocarcinoma of the fundic gland type (GA-FG).

INTERVENTION

Five patients were treated with endoscopic submucosal dissection.

OUTCOMES

Surgical outcomes were good. Esophagogastroduodenoscopy showed a scar with no recurrence, and no postoperative symptoms were observed from 3 to 43 months during the follow-up.

CONCLUSION

We present five cases of well-differentiated tubular adenocarcinoma that mimicked the fundic glands. Cell differentiation by MUC2, MUC5AC, MUC6, pepsinogen-I, and H+/K+-ATPase. Immunohistochemical findings in GA-FG suggested differentiation of the fundic glands. In addition, it has a low proliferation. p53 and Her-2 were negative, and β-catenin was positive in the cytoplasm, indicating that the pathogenesis of this tumor was different from that of traditional intestinal and diffuse gastric carcinomas. In summary, this neoplasm is rare and unusual. To better understand this issue, similar cases should be monitored in the future.

Gastric adenocarcinoma of the fundic gland: A review of clinicopathological characteristics, treatment and prognosis

Gastric adenocarcinoma of the fundic gland is a rare, well-differentiated gastric cancer entity, and very few patients transition to poorly differentiated tubular adenocarcinoma during progression. Gastric adenocarcinoma of the fundic gland originates from the mucosa of the gastric fundic gland, usually without chronic gastritis or intestinal metaplasia. Histologically, the tumor cells are closely arranged to form anastomosing tubular glands, and more than 95% of tumor cells differentiate towards chief cells. Most gastric adenocarcinoma of the fundic gland cases are characterized by submucosal involvement, but the tumor volume is usually small, with lymphatic and vascular invasion rarely observed. Therefore, endoscopic submucosal dissection can be an ideal treatment, leading to a favorable prognosis, and recurrence and metastasis of the disease are uncommon.

Gastric Adenocarcinoma of the Fundic Gland Type: A Case Report

BACKGROUND Gastric adenocarcinoma of the fundic gland type (GAFG) is an extremely rare neoplasm that consists of a mixed proliferation of oxyntic and chief cells. Differential diagnosis of GAFG is difficult in the absence of infiltration. Here, we report a case of GAFG and discuss the clinicopathological features. CASE REPORT A 78-year-old man was diagnosed with gastritis and reflux esophagitis, status after esophagectomy for carcinoma of the esophagus in 2015. The patient underwent repeated gastric biopsies in 2017 and an atypical epithelium was observed, but no diagnosis was confirmed. There was no evidence of tumor extension in the submucosa. The tumor was resected via endoscopic mucosal resection, and pathological examination was performed. Microscopic findings revealed an oxyntic-type gastric mucosa with atypical dense or dilated glands with abundant pale basophilic cytoplasm and round nuclei with prominent nucleoli. The majority of the tumor cells resembled chief cells, suggesting they were derived from gastric fundic glands. However, the tumor appeared to have no submucosal infiltration or focal stromal desmoplastic reaction. Sections stained positive for MUC6 and pepsinogen-I in chief cells, and H+/K+ ATPase and PDGFRa in parietal cells, but were mostly negative for CDX2, chromogranin A, synaptophysin, and CD10. Sections stained for mib-1 expressed very low proliferative activity, with an average of 10%. Staining for TP53 overexpression was negative. CONCLUSIONS Immunostaining markers are a supportive tool for histological diagnosis of GAFG. However, if there is no infiltration, as in our case, it is difficult to consider it as a malignant tumor. Further elucidation is needed in the future, including an officially accepted diagnostic name.

Gastric epithelial neoplasm of fundic-gland mucosa lineage: proposal for a new classification in association with gastric adenocarcinoma of fundic-gland type

BACKGROUND

Gastric adenocarcinoma of fundic-gland type (GA-FG) is a rare variant of gastric neoplasia. However, the etiology, classification, and clinicopathological features of gastric epithelial neoplasm of fundic-gland mucosa lineage (GEN-FGML; generic term of GA-FG related neoplasm) are not fully elucidated. We performed a large, multicenter, retrospective study to establish a new classification and clarify the clinicopathological features of GEN-FGML.

METHODS

One hundred GEN-FGML lesions in 94 patients were collected from 35 institutions between 2008 and 2019. We designed a new histopathological classification of GEN-FGML using immunohistochemical analysis and analyzed via clinicopathological, immunohistochemical, and genetic evaluation.

RESULTS

GEN-FGML was classified into 3 major types; oxyntic gland adenoma (OGA), GA-FG, and gastric adenocarcinoma of fundic-gland mucosa type (GA-FGM). In addition, GA-FGM was classified into 3 subtypes; Type 1 (organized with exposure type), Type 2 (disorganized with exposure type), and Type 3 (disorganized with non-exposure type). OGA and GA-FG demonstrated low-grade epithelial neoplasm, and GA-FGM should be categorized as an aggressive variant of GEN-FGML that demonstrated high-grade epithelial neoplasm (Type 2 > 1, 3). The frequent presence of GNAS mutation was a characteristic genetic feature of GEN-FGML (7/34, 20.6%; OGA 1/3, 33.3%; GA-FG 3/24, 12.5%; GA-FGM 3/7, 42.9%) in mutation analysis using next-generation sequencing.

CONCLUSIONS

We have established a new histopathological classification of GEN-FGML and propose a new lineage of gastric epithelial neoplasm that harbors recurrent GNAS mutation. This classification will be useful to estimate the malignant potential of GEN-FGML and establish an appropriate standard therapeutic approach.

Gastric adenocarcinoma of fundic gland (chief cell predominant type) coexisting with well differentiated intestinal adenocarcinoma: A case report

RATIONALE

Gastric adenocarcinoma of fundic gland (chief cell predominant type) (GA-FG-CCP) is a new, rare variant of gastric adenocarcinoma, which is characterized by mild nuclear atypia and specific immunohistochemical markers.

PATIENT CONCERNS

An 84-year-old Chinese man was referred to our hospital for endoscopic resection of a gastric lesion.

INTERVENTIONS

We performed endoscopic submucosal dissection, and successfully removed the lesion.

DIAGNOSIS

Esophago gastroduodenoscopy showed a slightly elevated lesion with a diameter of 22 mm in the posterior wall of cardia. Magnifying endoscopy with narrow band imaging revealed an abnormal microsurface and microvessels on the tumor surface. Endoscopic ultrasonography revealed a hypoechoic mass located in the first layer. The pathological diagnosis of the biopsy specimens indicated that the tumor was high grade intraepithelial neoplasia. The pathological diagnosis differed between the superficial and deeper part of the lesion. The superficial part was composed of a tubular structure with prominent atypia and was diagnosed as well differentiated intestinal adenocarcinoma. The deeper part was composed of a well-differentiated tubular adenocarcinoma mimicking the fundic gland cells, mainly the chief cells. The tumor cells showed mild nuclear atypia and was positive for pepsinogen-I (PG-I) and mucin-6 (MUC6). This deeper part was diagnosed as GA-FG-CCP.

OUTCOMES

The tumor was successfully removed. This patient had no discomfort during the follow-up period (10 months).

LESSONS

We present a rare case of GA-FG-CCP coexisted with well-differentiated tubular adenocarcinoma. GA-FG-CCP exists in the deep mucosal layer and the muscularis mucosa, which could not be found under endoscopy, but could be discerned in pathology with mild nuclear atypia and special biomarkers.

Endoscopic resection is a suitable initial treatment strategy for oxyntic gland adenoma or gastric adenocarcinoma of the fundic gland type

The aim of this study was to reveal the histological features of oxyntic gland adenomas and gastric adenocarcinoma of the fundic-gland type (GA-FG). We retrospectively examined the histological features of 126 lesions of oxyntic gland adenoma and/or GA-FG in 116 patients. The prevalence of oxyntic gland adenomas and GA-FG was approximately equal. The majority of the lesions were resected by endoscopic mucosal resection using a diathermic snare (EMR, n = 42) or endoscopic submucosal dissection (ESD, n = 72). Histologically, there were no lesions with invasion at the level of the muscularis propria or deeper, and lymphovascular invasion was present in 1.6%. Of the ESD and EMR specimens, there were no lesions that were positive for vertical margins. Among the eight GA-FG patients with deep (≥ 500 μm) submucosal invasion, six were treated with endoscopic resection alone, and no recurrence was documented. No patients died of the disease during the median follow-up period of 14.5 months. In conclusion, all lesions were confined to the mucosa or submucosa and were negative for vertical margins. Lymphovascular invasion was present in only 1.6% of the patients. Thus, we believe that endoscopic resection is a suitable initial treatment method for oxyntic gland adenoma and GA-FG.

Helicobacter pylori-negative Gastric Cancer

<i>Helicobacter pylori (H. pylori)</i>-negative gastric cancer is diagnosed when gastric malignancies are found in patients in <i>H. pylori</i>-naïve stomachs. There are four types of noncardiac <i>H. pylori</i>-negative gastric cancers. The signet ring cell-type poorly cohesive carcinoma is most common, followed by the chief cell-predominant type gastric adenocarcinoma of the fundic gland. Extremely well-differentiated adenocarcinoma of the corpus and well-differentiated pyloric gland cancers are rare outside Japan because of country-specific differences in diagnostic criteria. In endemic areas of <i>H. pylori</i> infection, strict criteria are required for diagnosing an <i>H. pylori</i>-naïve stomach. Both invasive and noninvasive <i>H. pylori</i> tests should show negative results in a subject without a history of <i>H. pylori</i> infection. Furthermore, the serum pepsinogen (PG) assay and endoscopic findings of the background gastric mucosa are required to discriminate subjects with past infections owing to spontaneous regression or unintended eradication of <i>H. pylori</i>. There should be no gastric corpus atrophy (PG I ≤70 ng/mL and PG I/II ≤3.0). Gastroscopy should reveal a regular arrangement of collecting venules without gastric xanthoma, metaplastic gastritis, or advanced atrophy over the angle. On biopsy, there should be no gastric atrophy, intestinal metaplasia, neutrophils, or <i>H. pylori</i> infiltration, and only a mild degree of mononuclear cell infiltration is permitted. The types and characteristics of noncardiac <i>H. pylori</i>-negative gastric cancers are summarized in this review, along with current diagnostic challenges found in Korea.

Gastric adenocarcinoma of the fundic gland type: clinicopathological features of eight patients treated with endoscopic submucosal dissection

BACKGROUND

Gastric adenocarcinoma of the fundic gland type (GA-FG) has been added to the 2019 edition of the World Health Organization's list of digestive system-associated cancers. This lesion differentiates toward the fundic gland and mostly involves chief cell-predominant differentiation with low-grade cytology. Clinicians and pathologists are still unaware of this rare disease; consequently, some cases are incorrectly diagnosed. This study aimed to investigate the clinicopathological features of GA-FG using retrospective analyses of endoscopic and pathological findings.

MATERIALS AND METHODS

Samples were collected from patients diagnosed with GA-FG. The clinical courses of all patients were monitored prospectively and reviewed retrospectively. Available clinical information, endoscopic features, pathological appearance, and follow-up data were assessed. Immunohistochemistry [mucin (MUC) 2, MUC5, MUC6, P53, CDX2, Ki67, SYN, CD56, CGA, β-catenin, and pepsinogen-I] was examined using Envision two-step method.

RESULTS

Eight cases of endoscopic submucosal dissection (ESD) were obtained from our institution. Patient age ranged from 48 to 80 years (mean, 65 years). Some patients were on acid-suppressing medication. Most lesions were located in the upper third (n = 7) and one was in the middle third of the stomach. Six lesions were of the superficial flat type, whereas two were of the superficial elevated type. Narrow-band imaging using magnifying endoscopy showed irregular microvascular patterns (MVPs) in four cases and regular MVPs in the remaining cases. All lesions were primarily solitary and ~ 6 mm in diameter (largest, 12 mm). The main body of the tumors were localized in the mucosal layer, of which six cases invade into the submucosal layer. Well-formed glands of chief cells were predominant. Tumor cells were positive for pepsinogen-I, MUC6, SYN, and CD56. Lymphatic and vascular infiltration and metastatic and recurrent disease were not observed in any case.

CONCLUSION

GA-FG, a well-differentiated adenocarcinoma with mild atypia, can be completely removed using ESD, with a favorable prognosis in patients.

Histopathologic Change of a Case of Gastric Oxyntic Neoplasm (Gastric Adenocarcinoma of Fundic Gland Mucosa Type) Through 5 Years With Concurrent Other Oxyntic Gland Lesions

Some gastric epithelial neoplasms show predominant chief cell differentiation (oxyntic gland neoplasms), in which the entity of "gastric adenocarcinoma of fundic gland type" was firstly designated, whereas a possible more aggressive subgroup "gastric adenocarcinoma of fundic gland mucosa type" (GA-FGM) was subsequently proposed. However, the histopathologic progression mode of these neoplasms has not been sufficiently reported. In this article, we describe a case of GA-FGM in which we could observe its progression during 5 years. The tumor was removed by endoscopic submucosal dissection 5 years after the first biopsy, which had already shown a feature of oxyntic gland neoplasm. During the follow-up period, the endoscopy revealed little change in the tumor appearance. However, the histology of endoscopic submucosal dissection showed submucosal extension with its histological progression. Besides, other oxyntic gland neoplasms of the stomach were observed metachronously or synchronously, giving an implication about a common pathogenetic basis of these lesions.

Precancerous lesions of the stomach, gastric cancer and hereditary gastric cancer syndromes

Gastric cancer accounts for about 6% of cancers worldwide, being the fifth most frequently diagnosed malignancy and the third leading cause of cancer related death. Gastric carcinogenesis is a multistep and multifactorial process and is the result of the complex interplay between genetic susceptibility and environmental factors. The identification of predisposing conditions and of precancerous lesions is the basis for screening programs and early stage treatment. Furthermore, although most gastric cancers are sporadic, familial clustering is observed in up to 10% of patients. Among them, hereditary cases, related to known cancer susceptibility syndromes and/or genetic causes are thought to account for 1-3% of all gastric cancers. The pathology report of gastric resections specimens therefore requires a standardized approach as well as in depth knowledge of prognostic and treatment associated factors.

Gastric Epithelial Polyps: When to Ponder, When to Panic

This review provides an overview of different types of gastric epithelial polyps. The polyps are classified based on their cell or epithelial compartment of origin. Some of these polyps can be considered reactive or nonneoplastic, whereas others are neoplastic in origin, are sometimes associated with a hereditary polyposis/cancer syndrome, and may have malignant potential. The aim of this review is to provide a pragmatic overview for the practicing pathologist about how to correctly diagnose and deal with gastric epithelial polyps and when (not) to ponder, and when (not) to panic.

Gastric adenocarcinoma of the fundic gland type: A case report

INTRODUCTION

Gastric adenocarcinoma of the fundic gland type (GA-FG) is a newly described entity that is characterized by well-differentiated neoplasm with unclear etiopathogenesis.

PATIENT CONCERNS

A 60-year-old Chinese man was referred to our hospital for abdominal distension.

DIAGNOSIS

Esophagogastroduodenoscopy (EGD) showed a depressed lesion found using in the greater curvature of the stomach. The pathological diagnosis of the biopsy specimens indicated that the tumor was GA-FG (chief cell predominant type, GA-FG-CCP).

INTERVENTIONS

Endoscopic submucosal dissection (ESD) was performed. The histopathological examination of the ESD specimen revealed gastric hyperplasia of the fundic gland type around the adenocarcinoma cells.

OUTCOMES

The surgical outcomes were good. The EGD showed a scar with no recurrence, and no symptoms were observed 1 year postoperatively during the follow-up.

CONCLUSION

We present a rare case of a depressed lesion with a pathogenic expression suggesting gastric hyperplasia of the fundic gland type around the adenocarcinoma cells. Considering the origin of oxyntic mucosa, we consider that it may develop into GA-FG. To understand this issue better, similar cases should be monitored in the future.

Oxyntic gland neoplasm of the stomach: expanding the spectrum and proposal of terminology

Gastric neoplasms exhibiting oxyntic gland differentiation typically are composed of cells with mild cytonuclear atypia differentiating to chief cells and to a lesser extent, parietal cells. Such tumors with atypical features have been reported also and terminology for this entity remains a matter of considerable debate. We analyzed and classified 26 tumors as oxyntic gland neoplasms within mucosa (group A, eight tumors) and with submucosal invasion. The latter was divided further into those with typical histologic features (group B, 14 tumors) and atypical features, including high-grade nuclear or architectural abnormality and presence of atypical cellular differentiation (group C, four tumors). Groups A and B tumors shared similar histologic features displaying either a chief cell predominant pattern characterized by monotonous chief cell proliferation, or a well-differentiated mixed cell pattern showing admixture of chief and parietal cells resembling fundic gland. In addition, group C tumors displayed atypical cellular differentiation, including mucous neck cell and foveolar epithelium. Moderate or even marked cytological atypia was noted in group C, whereas it was usually mild in the other groups except for three group B tumors with focal moderate atypia. More than 1000 μm submucosal invasion and lymphovascular invasions were recognized only in group C. Mutation analyses identified KRAS mutation in one group C tumor as well as GNAS mutation in in one group A and group B tumors. Intramucosal tumors appear to behave biologically benign and should be classified as "oxyntic gland adenoma". Those with submucosal invasion also have low malignant potential; however, a subset will have atypical features associated with aggressive histologic features and should be designated as "adenocarcinoma of fundic gland type". Especially, we suggest "adenocarcinoma of fundic gland mucosa type" for tumors with submucosal invasion exhibiting atypical cellular differentiation, because the feature is likely to be a sign of aggressive phenotype.

Gastric adenocarcinoma of fundic gland type after Helicobacter pylori eradication: A case report

BACKGROUND

Gastric adenocarcinoma of fundic gland type (GA-FG) has recently been proposed as a novel histological type of gastric cancer.

CASE SUMMARY

We report a case of GA-FG in a 77-year-old Chinese woman with epigastric distention who was referred to endoscopy for the management of an incidentally found submucosal tumor-like elevated lesion in the lower part of the gastric body. The tumor occurred after Helicobacter pylori (H. pylori) eradication therapy without long-term use of proton pump inhibitors. Complete and curable removal of the tumor was performed by endoscopic submucosal dissection. Histopathological findings showed numerous cells with basophilic cytoplasm and mildly atypical nuclei-like chief cells of the fundic gland. The tumor was observed to have the so-called “endless glands” pattern of the well-differentiated mixed phenotype. A safe resection margin without lymphatic and venous invasion was observed. As the tumor occurred after H. pylori eradication therapy, it is unknown whether there was a relationship with H. pylori eradication. The patient will be followed up by periodic gastroscopic observation.

CONCLUSION

In conclusion, we report a case of GA-FG after H. pylori eradication therapy without long-term proton pump inhibitors use. Further analysis of similar cases will reveal the clinical behavior of GA-FG.

Emerging evidence supports grouping by location of early gastric carcinoma for appropriate clinical management in Chinese patients

Gastric cancer is common in China. At present, early detection with prompt resection of early gastric carcinoma (EGC) is crucial for improving patient's survival. Because of high heterogeneity of EGC in Chinese patients we reviewed recent clinicopathological and molecular evidence and proposed a grouping EGC in three subgroups according to their location for appropriate management. In group 1 (cardia), most patients with EGC in this small location were elderly men. The tumors originated in the cardiac mucosa with a high proportion of cases with slightly elevated gross patterns and intestinal adenocarcinoma histology with moderate to well differentiation. Poorly cohesive carcinoma was infrequent. As the risk for lymph node metastasis in this kind of tumor was significantly lower than that in the distal stomach, endoscopic therapy is preferred. Group 2 (fundus-corpus), many patients with EGC in this large location were young women. The EGCs originated in the oxyntic mucosa with pure and mixed poorly cohesive carcinomas that are more commonly present in this area than in any other. Most tumors were poorly differentiated with a high risk for lymph node metastasis. Thus, endoscopic therapy may be appropriate for intramucosal, but not for submucosal, carcinoma. Group 3 (antrum-pylorus). EGC tumors arose from the antral mucosa, primarily because of Helicobacter pylori infection, following the Correa gastric cancer tumorigenetic pathway. Erosive and ulcerated gross patterns were most frequently observed. While most EGCs in this location were mainly intestinal adenocarcinomas, poorly differentiated EGCs were substantial in number. Because the risk of lymph node metastasis remains to be illustrated, clinical management requires an individualized approach. This preliminary observation requires verification in large nationwide multicenter studies.