Magnification Endoscopy and Chromoendoscopy in Evaluation of Specialized Intestinal Metaplasia in Barrett's Esophagus

Specialized intestinal metaplasia (SIM) in Barrett's esophagus is a risk factor of esophageal adenocarcinoma. It often occurs focally and cannot be distinguished from surrounding columnar epithelium with conventional endoscopy. The purpose of this study was evaluation of methylene blue (MB) staining and magnification endoscopy with comparison of pit-pattern classifications according to Endo and Guelrud, in detection of SIM in Barrett's esophagus. Twenty-five patients, aged 33-77 years (average 57 years), with displacement of Z line were prospectively enrolled and underwent gastroscopy with the use of magnification up to 115 times (Olympus GIF Q160Z). Biopsy for histopathologic examination was taken from sites stained with MB and/or places with particular pit patterns. A control group consisted of ten patients with normal gastro-esophageal junction. SIM was proved in nine patients, and significantly more frequently in patients with hiatal hernia and Barrett's segment longer than 3 cm. Round or thin linear pit patterns according to Guelrud's and small round and straight pit patterns according to Endo's classification were coupled with columnar epithelium. SIM was associated with deep linear and foveolar pit patterns in Guelrud's classification. Other pit patterns were less characteristic. Both classifications had high sensitivity (Endo's 85.7%, Guelrud's 92.8%) but poor specificity (respectively, 21.15 and 28.4%) in detection of SIM. Sensitivity and specificity of MB staining were, respectively, 71.4 and 40.6%. Despite existing association between mucosal surface structure and histology, we find no convincing data indicating that pit-pattern evaluation may replace multiple biopsies taken according to recommendations from Seattle for detection of SIM in Barrett's esophagus.