[Barrett's neoplasia: where is the problem?].

The Barrett mucosa is characterised by metaplastic transformation in the distal oesophagus from squamous epithelium into columnar-lined cells and shows an increased risk for progression into adenocarcinoma. Up to date an international definition of Barrett's oesophagus is still lacking and it is also difficult to separate low-grade dysplasia/intraepithelial neoplasia from high-grade dysplasia/intraepithelial neoplasia. The present review describes the criteria for the histological diagnosis, discusses the possibilities of endoscopic diagnosis and highlights the biomarkers of the Barrett mucosa.