Barrett esophagus is a complication of chronic GERD that is characterized by intestinal metaplasia within the esophageal squamous mucosa. The incidence of Barrett esophagus is rising; it is estimated to occur in as many as 10% of individuals with symptomatic GERD. White males are affected most often and typically present between 40 and 60 years of age. The greatest concern in Barrett esophagus is that it confers an increased risk for development of esophageal adenocarcinoma. Molecular studies suggest that Barrett epithelium may be more similar genetically to adenocarcinoma than to normal esophageal epithelium, consistent with the view that Barrett esophagus is a direct precursor of cancer. In keeping with this, epithelial dysplasia, considered to be a preinvasive lesion, develops in 0.2% to 1% of individuals with Barrett esophagus each year; its incidence increases with duration of symptoms and increasing patient age. Although the vast majority of esophageal adenocarcinomas are associated with Barrett esophagus, it should be noted that most individuals with Barrett esophagus do not develop esophageal cancer.
MORPHOLOGYBarrettesophagusisrecognizedendoscopicallyastonguesorpatchesofred,velvetymucosaextendingupwardfromthegastroesophagealjunction(
Fig.15.10A ).Thismetaplasticmucosaalternateswithresidualsmooth,palesquamous(esophageal)mucosaproximallyandinterfaceswithlight-browncolumnar(gastric)mucosadistally(
Fig.15.10BandC ).High-resolutionendoscopeshaveincreasedthesensitivityofBarrettesophagusdetection.
MostexpertsrequirebothendoscopicevidenceofabnormalmucosaabovethegastroesophagealjunctionandhistologicallydocumentedgastricorintestinalmetaplasiafordiagnosisofBarrettesophagus.Thedefiningfeatureofintestinalmetaplasia,andafeatureofBarrettesophagus,isthepresenceofgobletcells,whichhavedistinctmucousvacuolesthatstainpalebluebyH&Eandimparttheshapeofawinegoblettotheremainingcytoplasm(
Fig.15.10C ).Dysplasiaisclassifiedaslow-gradeorhigh-gradeonthebasisofmorphologiccriteria.Intramucosalcarcinomaischaracterizedbyinvasionofneoplasticepithelialcellsintothelaminapropria.
Diagnosis of Barrett esophagus is usually prompted by GERD symptoms and requires endoscopy and biopsy. The best course of management is a matter of debate, but most clinicians recommend periodic surveillance endoscopy with biopsy to screen for dysplasia. Dysplasia is often treated and more advanced lesions, including high-grade dysplasia and intramucosal carcinoma, always require therapeutic intervention. Available modalities include surgical resection (esophagectomy); newer approaches include photodynamic therapy, radiofrequency ablation, and endoscopic mucosectomy.
Fig. 15.10 Barrettesophagus.(A)NarrowbandimagingofBarrettesophagusduringendoscopy.Notethetanislandsofectopicmetaplasiawithinbluishsquamousmucosa.(B)GrossimageofBarrettesophagus(compareto