Intramucosal EGC Submucosal EGC
differentiated type without ulceration less than 30 mm in diameter
  with ulceration, less than 30 mm in diameter less than 500 mm submucosal penetration and without ulceration
undifferentiated type with ulceration, less than 20 mm in diameter  
Table 1: Criteria for ESD based on the Japanese gastric cancer treatment guidelines 2010 (ver. 3).