Intestinal metaplasia (IM) and dysplasia in Barrett's esophagus are recognized surrogates for esophageal adenocarcinoma risk.
While few would argue with the "hunt for dysplasia," there is a divide regarding the usefulness of the histological confirmation of intestinal metaplasia in endoscopically-apparent long-segment Barrett's esophagus.
Dr Rebecca Harrison and colleagues from the UK, USA, Australia and Canada aimed to assess the frequency of intestinal metaplasia in 125 consecutive patients with columnar-lined esophagus and to determine the optimal biopsy protocol to detect intestinal metaplasia.
|67.9% of endoscopies had intestinal metaplasia|
| The American Journal of Gastroenterology |
296 endoscopies were performed over a 4-yr period in Barrett's esophagus segments of mean length 4 cm (range 1-11 cm) at a single center and the resulting biopsies were analyzed retrospectively.
Biopsies were all processed with routine hematoxylin and eosin (H&E) staining, and a subset (N = 92) was subject to alcian blue/periodic-acid Schiff staining.
Using H&E staining, the team found that the optimum number of biopsies to diagnose intestinal metaplasia was 8 per endoscopy, mean 67.9% endoscopies having intestinal metaplasia.
In contrast, if only 4 were taken the yield was 34.7% with intestinal metaplasia.
Unless more than 16 biopsies were taken (100% yield of intestinal metaplasia), no additional significant detection was achieved.
Using additional alcian blue/periodic-acid Schiff staining only had a marginal benefit, with 5.4% of new cases of intestinal metaplasia being identified.
There is a proximal cephalo-caudal gradient of intestinal metaplasia, especially with increased chronological age, but doing repeat endoscopies on patients did not increase the detection of intestinal metaplasia.
Dr Harrison concluded that, "At least 8 random biopsies is the minimum to be taken, and analyzed with conventional H&E staining, to diagnose benign intestinal metaplasia", and that "taking more biopsies did not statistically increase the diagnosis of intestinal metaplasia except when greater than 16 were taken when 100% yield was obtained".