Gastritis cystica profunda is associated with aberrant p53 and Epstein-Barr virus in gastric cancer: A clinicopathological, immunohistochemical and in situ hybridization study

Chronic active and atrophic gastritis as significant contributing factor to the development of gastric cystica profunda

Gastric cystica profunda (GCP) is an uncommon but underestimated gastric lesion. Its precancerous potential determines its significance. In addition to previous mucosa injury due to operations, biopsy or polypectomy, chronic active and atrophic gastritis may also lead to the development of GCPs. By carefully examining the stomach and taking biopsy samples from the susceptible regions, the stage of atrophy can be determined. Chronic atrophic gastritis is a risk factor for cancer evolvement and it can also contribute to GCPs formation. GCPs frequently occur close to early gastric cancers (EGCs) or EGC can arise from the cystic glands. Endoscopic resection is an effective and minimally invasive treatment in GCP.

The viral etiology of EBV-associated gastric cancers contributes to their unique pathology, clinical outcomes, treatment responses and immune landscape

Epstein-Barr virus (EBV) is a pathogen known to cause a number of malignancies, often taking years for them to develop after primary infection. EBV-associated gastric cancer (EBVaGC) is one such malignancy, and is an immunologically, molecularly and pathologically distinct entity from EBV-negative gastric cancer (EBVnGC). In comparison with EBVnGCs, EBVaGCs overexpress a number of immune regulatory genes to help form an immunosuppressive tumor microenvironment (TME), have improved prognosis, and overall have an "immune-hot" phenotype. This review provides an overview of the histopathology, clinical features and clinical outcomes of EBVaGCs. We also summarize the differences between the TMEs of EBVaGCs and EBVnGCs, which includes significant differences in cell composition and immune infiltration. A list of available EBVaGC and EBVnGC gene expression datasets and computational tools are also provided within this review. Finally, an overview is provided of the various chemo- and immuno-therapeutics available in treating gastric cancers (GCs), with a focus on EBVaGCs.

Large gastric hamartomatous inverted polyp accompanied by advanced gastric cancer: A case report

BACKGROUND

Gastric hamartomatous inverted polyps (GHIPs) are benign polyps of the gastric submucosal layer. Currently there are 52 reported cases in the English literature. According to a literature review, approximately 27% of GHIPs show a coexisting carcinoma.

CASE SUMMARY

A 66-year-old man was referred to our institution with ulcerative lesions detected on esophagogastroduodenoscopy (EGD) during a regular check-up. Other medical findings were nonspecific. The lesions had borderline histologic features that could not exclude malignancy and were followed up with three EGDs and biopsies at intervals of 3 mo. The latest biopsy was revealed as an adenocarcinoma. A total gastrectomy was performed to remove the tumor. The surgical specimen revealed a 6.9 cm × 4.5 cm sized GHIP with a coexisting 1.6 cm sized well-differentiated adenocarcinoma which extended to the muscularis propria. The malignancy did not originate from the GHIP but showed an overlap.

CONCLUSION

A large GHIP, which was unusually presented as an ulcerative lesion, was surgically removed, and was accompanied by advanced gastric cancer. Regular follow-up and thorough examinations of ulcerative lesions with equivocal biopsy have resulted in appropriate diagnosis and treatment. Therefore, aggressive intervention may be beneficial if GHIP is suspected.

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.