Definition, Derivation, and Diagnosis of Barrett's Esophagus: Pathological Perspectives

More than 60 years have elapsed since Barrett described the condition that continues to bear his name. Despite much research, clinical and basic, the defining features and the diagnosis of columnar-lined esophagus (CLO) are still embroiled with controversy and uncertainty. For pathologists, these controversies are notorious. The disease has been defined by the pathological demonstration of "specialized intestinal metaplasia" and yet there is compelling evidence that this approach is flawed due to sampling issues, poor levels of agreement between expert pathologists as to what constitutes "goblet cells," and the fact that most glandular epithelium in the esophagus is "intestinalized," even if goblet cells are not demonstrable. We believe that reliance on such pathological features can result in erroneous diagnoses of CLO and that the endoscopic diagnosis of CLO is more reliable with pathology corroborative in uncertain cases, when there is stricturing and/or ulceration and in shorter segment disease. Intriguingly, there are recent research findings that elucidate our understanding of the pathogenesis and the derivation of CLO and the way that initial gastric metaplasia converts to the unstable and neoplasia-associated intestinal phenotype. Even so, more research is required to enable a better understanding of the pathogenesis of CLO and to further improve the current management of the disease and its neoplastic complications.