Gastric polyps: an update of their pathology and biological significance

Gastric polyps are clinically important lesions that are frequently encountered in routine pathology (2-3% of all gastroscopies). Polyps may occur sporadically or in polyposis syndromes, such as familial adenomatous polyposis coli (FAP), Peutz-Jeghers syndrome, juvenile polyposis, Cowden's disease and Cronkhite-Canada syndrome. In biopsy specimens taken during routine gastroscopic examinations, it is almost always possible to differentiate between neoplastic and non-neoplastic polyps and to type polyps. In this review, we focus on the morphological spectrum of gastric polyps in an attempt to assist the pathologist and the gastroenterologist in recognising the lesion and in treating patients with gastric polyps, respectively. Further, we propose that the World Health Organization (WHO) classification should be modified to include the following categories: non-neoplastic polyps (WHO: tumour-like lesion), hamartomatous polyps/polyps of polyposis syndromes (WHO: tumour-like lesion), heterotopic tissue polyps (WHO: tumour-like lesion), neoplastic polyps (WHO: epithelial, non-epithelial and endocrine tumours) and reactive polypoid lesions.