Columnar mucosa and intestinal metaplasia of the esophagus: fifty years of controversy.

OBJECTIVE To outline current concepts regarding etiology, diagnosis, and treatment of intestinal metaplasia of the esophagus and cardia. SUMMARY BACKGROUND DATA Previously, endoscopic visualization of columnar mucosa extending a minimum of 3 cm into the esophagus was sufficient for the diagnosis of Barrett's esophagus, but subsequently the importance of intestinal metaplasia and the premalignant nature of Barrett's have been recognized. It is now apparent that shorter lengths of intestinal metaplasia are common, and share many features of traditional 3-cm Barrett's esophagus. METHODS Themes and concepts pertaining to intestinal metaplasia of the esophagus and cardia are developed based on a review of the literature published between 1950 and 1999. RESULTS Cardiac mucosa is the precursor of intestinal metaplasia of the esophagus. Both develop as a consequence of gastroesophageal reflux. Intestinal metaplasia, even a short length, is premalignant, and the presence of dysplasia indicates progression on the pathway to adenocarcinoma. Antireflux surgery, as opposed to medical therapy, may induce regression or halt progression of intestinal metaplasia. The presence of high-grade dysplasia is frequently associated with an unrecognized focus of adenocarcinoma. Vagal-sparing esophagectomy removes the diseased esophagus and is curative in patients with high-grade dysplasia. Invasion beyond the mucosa is associated with a high likelihood of lymph node metastases and requires lymphadenectomy. CONCLUSIONS Despite improved understanding of this disease, controversy about the definition and best treatment of Barrett's esophagus continues, but new molecular insights, coupled with careful patient follow-up, should further enhance knowledge of this disease.