Tumors of the esophagogastric junction should be classified not only according to the TNM system with regards to tumor penetration (T stage), presence of lymph nodes (N stage) and distant metastases (M stage), also with regards to tumour location, namely oesophageal versus gastric extent. This has significant consequences with regards to surgical strategy. Initially, the Siewert classification 1 provided a good overview and was based on the location of the tumor center ... more on Endoscopy-Campus.com: