[Barrett's esophagus and carcinoma: Recommendations of the S2k guideline 2014 and the S3 guideline 2015].

In the current S2k guideline for gastroesophageal reflux disease and the new S3 guideline for esophageal cancer, histopathological evaluation of Barrett's esophagus has been revised and supplemented. The histological diagnosis of Barrett's esophagus still requires the proof of a specialized intestinal metaplastic epithelium (columnar epithelium with goblet cells). Barrett mucosa must be classified as negative, unclear/doubtful, and positive concerning the intraepithelial neoplasia (IEN)/dysplasia according to the current WHO guideline. Each IEN should be confirmed by an external second opinion due to poor interobserver variability. The pathological classification is of decisive importance here, since the recommended monitoring intervals are based solely on the ground of proved IEN. Risk factors in endoscopic resection specimens such as depth of infiltration (m1-m4; sm1-sm3; distance in µm); angioinvasion (L, V); grading and lateral/basal resection margin have to be reported. In surgical specimens, the reference of the tumor center to the gastroesophageal junction and in the neoadjuvant situation the tumor regression should be documented.