34th European Congress of Pathology - Abstracts
Nielsen, Patricia Switten; id_orcid 0000-0002-7859-6321, Georgsen, Jeanette Bæhr; id_orcid 0000-0002-9452-2920, Vinding, Mads Sloth, Østergaard, Lasse Riis, Steiniche, Torben; id_orcid 0000-0001-5689-3555
Abstract
Background & objectives: Chronic atrophic gastritis may contribute to the phenotype of gastric polyps in familial adenomatous polyposis (FAP).As the prevalence of Helicobacter-pylori infection in Portugal is up to 90%, we aim to characterize gastric polyps in a series of Portuguese patients.Methods: Fifty-six FAP patients followed up at our hospital in High-Risk Consultation of Digestive Tumours, from 1992 to 2021 were retrospectively selected.Thirty-two patients were males (57.1%), and the medium age was 52 (range: 26-87).Clinicopathological features, with particular emphasis on periodic upper endoscopic examinations, were studied.IBM SPSS (Release 27.0) was used for statistical analysis.Results: Our series encompassed 95 gastric polyps, including 53 (55.8%) fundic gland polyps (FGPs) without dysplasia (n=34) or with dysplasia (n=19) and 42 (44.2%)intestinaltype adenomas.Half of FAP patients (n=28, 50.0%) developed endoscopically visible gastric polyps, including FGPs in 12 patients (21.4%) and adenomas with or without FGPs in 16 patients (28.6%).Foveolar-type adenomas and pyloric gland adenomas were not identified in this series.Intestinaltype adenomas occurred predominantly in the distal stomach (62.5%, p=0.031), were larger than 7mm in 9/16 cases (56.3%, p=0.03), and were more frequently associated with duodenal adenomas (87.5%, p<0.001).Chronic atrophic gastritis and intestinal metaplasia was observed in the background mucosa in most cases (75.0%, p=0.009).Conclusion: To our knowledge, this is the first Western series showing high prevalence of intestinal-type adenomas in FAP patients, comparable to Asian studies.Chronic atrophic gastritis/intestinal metaplasia are likely responsible for this difference, with risk of neoplastic transformation and management implications.Endoscopists should have a high degree of suspicion in FAP patients and low threshold to biopsy/excision of gastric polyps, particularly in patients with chronic atrophic gastritis/intestinal metaplasia, in those with distal gastric polyps with worrisome features (namely >7mm) and/or duodenal adenomas.