No abstract

The relative prevalence of fundic gland polyps in this population was much higher than that reported earlier, most likely because of the widespread use of proton pump inhibitors. H. pylori- and atrophy-associated polyps, including adenomas, were less common than in earlier series.

Increased numbers of intraepithelial lymphocytes (lymphocytosis) can be found in the esophagus, stomach, small intestine, and colon in a variety of clinical circumstances. This review, directed at practicing pathologists, portrays the normal resident lymphocyte population in the mucosa of each segment of the digestive tract and discusses the different situations that may result in quantitative or qualitative alterations of intraepithelial lymphocytes. Esophageal lymphocytosis has not been fully characterized and its clinical significance, if any, awaits definition. Thus, this diagnosis is presently discouraged. In the stomach, it is particularly important to exclude Helicobacter pylori infection and celiac sprue before diagnosing lymphocytic gastritis. Duodenal lymphocytic infiltrates, inextricably tied with alterations of the villous architecture of the mucosa, are often caused by gluten sensitivity. However, similar morphologic changes may be caused by a vast array of other conditions that must be carefully considered and excluded. Lymphocytic and collagenous colitis are most often unexplained, but their frequent association with autoimmune conditions or certain medications deserve a thorough investigation in each case. Using a combination of histologic and clinical clues, a cause for the intraepithelial lymphocytic infiltration can be identified in many instances. As some of the associated conditions are amenable to effective treatment, the importance of diligently seeking such associations before resorting to a diagnosis of primary lymphocytosis is emphasized.

1-4% of patients who undergo gastric biopsy have gastric polyps. These lesions may be true epithelial polyps, heterotopias, lymphoid tissue, or stromal lesions. Hyperplastic polyps, which arise in patients with underlying gastritis, and fundic-gland polyps, which are associated with PPI therapy, are the most common gastric polyps; however, prevalence varies widely relative to the local prevalence of Helicobacter pylori infection and use of PPI therapy. Some polyps have characteristic topography, size, and endoscopic appearance. Approximately 20% of biopsy specimens identified endoscopically as polyps have no definite pathological diagnosis. Evaluation of the phenotype of the gastric mucosa that surrounds a lesion will provide significant information crucial to the evaluation, diagnosis and management of a patient. The presence of a gastric adenoma should prompt the search for a coexistent carcinoma. The endoscopic characteristics, histopathology, pathogenesis, and management recommendations of polyps and common polypoid lesions in the stomach are discussed in this Review.