Hyperplastic polyps of the duodenum: an unusual histological finding.

A 58-year-old man underwent upper gastrointestinal surveillance endoscopy for Barrett's oesophagus. This showed a possible gastric ulcer, although histological examination was normal. Follow-up endoscopy showed white ridges in the distal duodenum and these were subjected to biopsy. Histological examination of the biopsy specimens showed polypoid duodenal mucosa showing features similar to those of a hyperplastic polyp of the colon. In addition, the mucosal surface was focally of gastric surface type. The features were interpreted overall as most likely to represent an unusual form of regenerative change in the setting of previous chronic inflammatory mucosal damage. The case is presented as an unusual histological phenomenon at this site; it would be important not to overdiagnose neoplasia in this situation.