OMED E-Newsletter Issue 8, 2009: Brainteaser/image of the month
This is the duodenal cap of a 55 year old man undergoing gastroscopy for dyspepsia. He used to drink 1-2 glasses of wine each day but has recently reduced his alcohol intake as he found it to exacerbate his symptoms. He finished a one month course of a proton pump inhibitor six weeks earlier. The symptoms which settled with the therapy are now returning.
What is the most likely reason for the mucosal appearance in the duodenal cap?
- gastric metaplasia
- intestinal metaplasia
- scarring from previous ulceration
- hyperplastic polyps
- duodenal adenoma
Explanation
Option A is correct. Intestinal metaplasia is found in the stomach and is regarded as an intermediate step between gastric atrophy and dysplasia which may subsequently develop into intestinal-type gastric cancer.
In this case, the duodenal appearance is typical of gastric metaplasia. Areas of gastric metaplasia in the duodenum can be colonised by Helicobacter pylori, causing duodenitis. The extent of gastric metaplasia is related to the amount of acid entering the duodenum. It is lowest in patients with pernicious anaemia and highest in patients with Zollinger-Ellison syndrome. Patients with duodenal ulceration produce twice as much as normal. The mechanism for this is thought to be the predominantly antral gastritis which suppresses the somatostatin cells and increases gastrin release from the G cells in the gastric antrum.