Table 3.

Histological grading criteria.

Score	Lymphocyte	Crypt	Colon wall
	infiltration∗	aberrant	aberrant
1	10%	Few deepening and distortion	The structure of colon wall is integrated.
2	10–25%	Mild deepening and distortion	Colon wall thickening, no ulceration
3	25–50%	Medium deepening distortion	Vascular proliferation, colon wall thickening invading into muscular layer, no ulceration
4	>50%	Severe deepening distortion	Colon wall thickening invading into muscular layer with ulceration

^∗The lymphocyte infiltration was observed at 400× magnification.