Gastric Epithelial Polyps: When to Ponder, When to Panic

Novel classification of gastric polyps: The good, the bad and the ugly

Gastric polyps (GPs) are increasingly common. On upper endoscopy, they should be examined with white light and occasionally chromoendoscopy, and their morphology classified according to the Paris classification. Most GPs have a typical endoscopic appearance and can be associated with diseases like Helicobacter pylori infection. Histological examination is necessary for an accurate diagnosis. While most polyps are non-neoplastic and do not require treatment, some carry a risk of malignancy or are already malignant. Therefore, understanding the diagnosis, classification, and management of GPs is crucial for patient prognostication. Our new classification categorizes GPs into "good", "bad", and "ugly" based on their likelihood of becoming malignant. We aim to provide descriptions of the endoscopic appearance, pathology, treatment, and follow-up for different GPs, as well as clinical management flowcharts.

Pathology of Gastrointestinal Polyposis Disorders

Gastrointestinal polyposis disorders are a group of syndromes defined by clinicopathologic features that include the predominant histologic type of colorectal polyp and specific inherited gene mutations. Adenomatous polyposis syndromes comprise the prototypical familial adenomatous polyposis syndrome and other recently identified genetic conditions inherited in a dominant or recessive manner. Serrated polyposis syndrome is defined by arbitrary clinical criteria. The diagnosis of hamartomatous polyposis syndromes can be suggested from the histologic characteristics of colorectal polyps and the association with various extraintestinal manifestations. Proper identification of affected individuals is important due to an increased risk of gastrointestinal and extragastrointestinal cancers.

Activating KRAS and GNAS mutations in heterotopic submucosal glands of the stomach

BACKGROUND

The heterotopic submucosal gland (HSG) is a common incidental finding in gastrectomy specimens. The majority of HSGs are small incidental lesions, which are also known as gastritis cystica profunda. However, larger lesions may appear as an inverted growth of well-organized mucosa referred to as gastric inverted polyps.

METHODS

To determine whether genetic alterations are involved in HSG development, we analyzed 63 gastric HSG lesions using targeted next-generation sequencing and immunohistochemistry.

RESULTS

Histologically, HSG lesions consistently had areas of pyloric gland differentiation with variable extent of foveolar differentiation. Although the background mucosa showed intestinal metaplasia in most cases (98%), intestinal-type epithelium was seen in only one HSG lesion (2%). Sequencing analysis identified activating KRAS, BRAF, CTNNB1, and GNAS mutations in 34 (54%), 1 (2%), 1 (2%), and 7 (11%) lesions, respectively. HSG lesions harboring a KRAS mutation were more likely to present extensive foveolar differentiation (P = 0.013) and absence of parietal cells (P = 0.0081). Five HSG lesions had a dysplastic component, and concordant genetic alterations were detected between the non-dysplastic and dysplastic areas of two lesions that were successfully analyzed. Immunohistochemical staining demonstrated diffuse expression of mutant KRAS protein in lesions with the most common genetic alteration, KRAS G12D.

CONCLUSIONS

Our study demonstrated that a major proportion of HSGs were proliferative lesions associated with oncogenic mutations, with more than half of lesions harboring activating KRAS mutations.

Juvenile polyposis diagnosed with an integrated histological, immunohistochemical and molecular approach identifying new SMAD4 pathogenic variants

Juvenile polyposis (JP) is a rare familial syndrome characterized by the development of numerous hamartomatous polyps of the gastrointestinal tract and by an increased risk of developing gastrointestinal cancers. It follows a pattern of autosomal dominant inheritance and is associated with germline variants of SMAD4 or BMPR1A genes. Differential diagnosis may be difficult based on histology alone, due to morphological similarities to other familial syndromes. Here we report a case of familial JP diagnosed in a 50-years woman with a familial history positive for gastrointestinal cancers and other tumor types. The patient presented with severe iron deficiency anemia and showed numerous polyps in the stomach and jejunum according to endoscopy and imaging. She underwent an intra-gastric laparoscopic removal of the major gastric polyp, followed by jejunal exploration and resection of a segment with multiple neoformations. Histological examination revealed the presence of hamartomatous polyposis. Gastric and intestinal samples were analyzed with next-generation sequencing. Molecular analysis showed that the patient harbored a germline splicing site variant of SMAD4, c.1139 + 3A > G, which was complemented by different somatic variants of the same gene in the different polyps. Immunohistochemistry for SMAD4 confirmed loss of protein expression in the polyps, with regular expression in normal cells. cDNA sequencing further confirmed the findings. We thus definitively diagnosed the woman as having JP thanks to an integrated approach based on histology, immunohistochemistry and molecular analysis. The identified variants, all previously reported as variants of unknown significance, were classified as pathogenic as they complemented each other leading to SMAD4 loss.

Analysis of pathological characteristics and nursing intervention of patients with gastric polyps based on image stitching algorithm and endoscopy

Objectives:

The paper uses image stitching algorithm to understand the clinical and pathological characteristics of gastric polyps under gastroscope, and provides objective basis for the clinical diagnosis and treatment of gastric polyps and nursing intervention.

Methods:

The endoscopic, pathological data and surgical conditions of 111 patients with gastric polyps detected in the hospital from January 2017 to August 2019 were retrospectively analyzed.

Results:

The elderly patients (≥60 years old) in this group were those with high incidence of gastric polyps (56.8%); 80 patients with single polyps (72.1%), 31 patients with multiple polyps (27.9%); polyps were mainly located in the stomach (53.2%); polyps diameter ≤0.5cm are more common (69.4%); polyps are mainly hyperplastic polyps (40.5%) and inflammatory polyps in 37 cases (33.3%). Polyps were removed by biopsy forceps in 30 cases, endoscopic submucosal injection of 0.9% NaCl solution combined with high-frequency electrosurgical removal of 54 cases, endoscopic mucosal resection (EMR) in 6 cases, and endoscopic submucosal dissection (ESD) in treatment of the 4 cases, the remaining 17 cases were treated with surgery, and 12 patients were followed up, 2 of whom relapsed.

Conclusion:

Gastric polyps are small in diameter and mostly single; polyps are mainly located in the stomach body, mainly hyperplastic polyps; treatment methods are mostly endoscopic resection, and there is a possibility of recurrence after polypectomy, and follow-up should be strengthened. Full preparation before the operation, close cooperation during the operation, and careful postoperative care are important links to ensure the safety of the operation and reduce complications such as upper gastrointestinal bleeding.

Gastritis, Gastric Polyps and Gastric Cancer

Gastric cancer is still an important disease causing many deaths worldwide, although there has been a marked reduction in prevalence during the last few decades. The decline in gastric cancer prevalence is due to a reduction in Helicobacter pylori infection which has occurred for at least 50 years. The most probable mechanism for the carcinogenic effect of H. pylori is hypergastrinemia since H. pylori infected individuals do not have increased risk of gastric cancer before the development of oxyntic atrophy. When atrophy has developed, the carcinogenic process continues independent of H. pylori. Autoimmune gastritis also induces oxyntic atrophy leading to marked hypergastrinemia and development of ECL cell neoplasia as well as adenocarcinoma. Similarly, long-term treatment with efficient inhibitors of acid secretion like the proton pump inhibitors (PPIs) predisposes to ECL cell neoplasia of a different degree of malignancy. Contrasting the colon where most cancers develop from polyps, most polyps in the stomach have a low malignant potential. Nevertheless, gastric polyps may also give rise to cancer and have some risk factors and mechanisms in common with gastric cancer. In this overview the most common gastric polyps, i.e., hyperplastic polyps, adenomatous polyps and fundic gland polyps will be discussed with respect to etiology and particularly use of PPIs and relation to gastric carcinogenesis.