Figure 1. Examples of determination in surface features and fold convergency. (a) A 1.5 cm cancer with deep submucosal invasion in the transverse colon. The surface of the lesion is determined to be nodular. There is a fold convergency towards the protrusion (arrows). (b) A 0.9 cm cancer with deep submucosal invasion in the sigmoid colon. There is a smooth protrusion with fold convergency (arrows).