R-2 Some features Precursor favored location gross patterns middle third exophytic polypoid ec chronic esophagitis barrett esophagus esophagus fungating endophytic ulcerative diffuse infiltrative GC atrophic gastritis lesser curvature of gastric adenoma antropyloric region Same CR villous adenoma ulcerative colitis rectum Same FAP mucinous mass with a gel-colloidR-2 Precursor favored location gross patterns EC chronic esophagitis barrett esophagus GC atrophic gastritis gastric adenoma CRC villous adenoma ulcerative colitis FAP middle third esophagus lesser curvature of antropyloric region rectum exophytic polypoid / fungating endophytic ulcerative diffuse infiltrative Same Same mucinous mass with a gel-colloid Some features