Table 2.

Siewert classification for gastroesophageal junction carcinomas

Classification	Description
Type I	Adenocarcinoma of the distal esophagus, which usually arises from an area of Barrett’s esophagus and which may infiltrate the GEJ from above. Located more than 1 to 5 cm proximal to GEJ.
Type II	True carcinoma of the cardia arising from the cardiac epithelium or an area of Barrett’s esophagus at the GEJ. Also referred to as “junctional carcinoma.” Located within 1 cm proximal and 2 cm distal to GEJ.
Type III	Subcardial gastric carcinoma that infiltrates the GEJ and distal esophagus from below. Located more than 2 to 5 cm distal to GEJ.

Abbreviation: GEJ = gastroesophageal junction. From Siewert & Stein.¹⁰