Polyps and tumour-like lesions of the small intestine

Lesions come to clinical attention because they cause obstructive symptoms or are incidentally detected during upper endoscopy. Sporadic adenomas are found more frequently in the peri-ampullary area than the more distal small bowel. Although sporadic duodenal adenomas are rare, they are universally present in adult familial adenomatous polyposis patients. Peutz-Jeghers syndrome classically has three components: gastrointestinal polyposis, perioral pigmentation and an autosomal dominant pattern of inheritance. Peutz-Jeghers syndrome has a well-established cancer risk, and many patients die from malignancies, often at a comparatively young age. Sporadic juvenile polyps occur almost exclusively in the distal colorectum, with rare lesions occurring more proximally in the large bowel. Brunner’s gland hyperplasia is commonly encountered in association with peptic duodenitis, and it is therefore mostly limited to the duodenal bulb. Small myo-epithelial hamartomas composed of dilated gland elements and surrounded by muscle occur in the duodenum, usually in relation to the ampulla of Vater.