The latest of several such candidates for use in BE surveillance is a small peptide sequence which has been

shown to bind specifically to the surface of dysplastic mucosa ex vivo; this bound peptide can be detected endoscopically by use of a fluorescent Epigenetics inhibitor tag.39 Rigorous assessments of the clinical utility of molecular probes for BE surveillance should appear in the next few years. A possible major limitation of using a highly specific probe is the considerable diversity of genetic changes seen in EA4. The demonstrated ability of endoscopic confocal microscopy to display mucosal histology is an impressive and provocative technical development. The most recent evaluations of its accuracy suggest that variability of diagnoses among observers is

a significant issue,40,41 which is no surprise, given the practical issues of interpretation of traditional biopsies discussed below. Another important limitation of this technique is that it may not provide sufficient opportunity for later review of histologic interpretations by another “pathologist” which, as discussed below, is so important to good management of BE. Considerably more research needs to be done before endoscopic confocal microscopy might be proven as a valid, routine diagnostic approach for mucosal assessment in BE. Pech and colleagues have used a Japanese learn more surface topographic classification (originally designed to aid recognition of early gastric cancers suitable for endoscopic mucosal resection), to reliably subdivide 380 early EAs into five topographic types. Most BE centers have adopted this classification, but early data suggest that it is not sufficiently sensitive for use as a primary method for defining the clinically crucial depth of penetration

of early EA.42 High frequency endoscopic ultrasound is a theoretically attractive option for staging early EA,42 but unfortunately this method has an unacceptably low (less than 30%) sensitivity for detection of submucosal penetration by early, mainly surveillance-detected EA, Tacrolimus (FK506) when histopathologic examination of endoscopically resected EA is used as the gold standard.43,44 These data relegate endoscopic ultrasound to a secondary role for staging apparently early EA. Endoscopic resection presents the pathologist with an extensive “surgical” specimen which gives a highly accurate measure of the extent of EA, both into the depth and along the length of the esophagus. The determination whether EA is confined to the mucosa is the crucial variable, since if this is so, there is only a low risk of metastatic spread: by contrast, penetration of EA into the submucosa to any degree not only makes complete local removal by endoscopic therapy difficult to achieve, but is also associated with a much higher risk of lymph node metastases irrespective of the depth of submucosal penetration.