Background: The use of methylene blue chromoendoscopy in the diagnosis of specialized intestinal metaplasia in short-segment Barrett's esophagus is controversial. This study evaluated the use of magnifying endoscopy with methylene blue for this purpose.
Methods: A total of 30 patients (21 men, 9 women; median age 61 years, range 32-79 years) with short lengths of columnar-lined esophagus were enrolled in a prospective trial of magnifying endoscopy with methylene blue in which the appearance after methylene blue staining was used to target biopsy specimens. Patients were screened for Helicobacter pylori infection, and only those without infection were enrolled (because many Japanese patients have pan-gastritis caused by H pylori infection, and intestinal metaplasia distal to the squamocolumnar junction may be secondary to H pylori-induced gastritis). All biopsy specimens were stained with H and E; MUC2 immunostaining was used to identify specialized intestinal metaplasia.
Results: Thirty patients with short-segment columnar-lined esophagus underwent magnifying endoscopy with methylene blue. Ninety-three biopsy specimens were obtained, 33 from methylene blue-stained areas and 60 from unstained areas, each about 7 mm from the marginal edge of stained areas. Specialized intestinal metaplasia was confirmed in biopsy specimens from 28 of the 33 stained areas (sensitivity 84.8%); in biopsy specimens from 55 of the 60 unstained areas, specialized intestinal metaplasia was not found (specificity 91.7%). In magnified views of methylene blue-positive areas, a tubular, cavernous, or elliptical pattern was seen. Sixteen of 21 men (76.2%) and 3 of 9 women had specialized intestinal metaplasia, and short-segment Barrett's esophagus was diagnosed in these patients. Even in patients with less than 1 cm of columnar-lined esophagus, 8 of 10 stained areas contained specialized intestinal metaplasia (sensitivity 80%) and 23 of 24 unstained areas did not (specificity 95.8%). Six of 12 patients (50%) with less than 1 cm of columnar-lined esophagus had specialized intestinal metaplasia. In total, 19 of 30 patients had specialized intestinal metaplasia.
Conclusions: Magnifying endoscopy with methylene blue selectively detects specialized intestinal metaplasia within short-segment columnar-lined esophagus.