Endoscopic treatment for gastrointestinal stromal tumor: Advantages and hurdles

Figure 2 Classification of gastrointestinal stromal tumors according to the location in the gastric wall. A: Type I is a gastrointestinal stromal tumor (GIST) that has a very narrow connection with the proper muscle layer and protrudes into the luminal side like a polyp; B: Type II has a wider connection with the proper muscle layer and protrudes into the luminal side at an obtuse angle; C: Type III is located in the middle of the gastric wall; D: Type IV protrudes mainly into the serosal side of the gastric wall. White dotted lines indicate the area dissected from the proper muscle layer. 1: Mucosa; 2: Submucosa; 3: Circular layer of proper muscle; 4: Longitudinal layer of proper muscle.