Pathological study of distal mesorectal cancer spread to determine a proper distal resection margin

Table 3 Mode of distal mesorectal and intramural spread of lower rectal cancer.

Number	Pattern ofgrowth	Tumor Differentiation	pTNMstage1	Layer ofspread	Mode ofspread	Maximum extentin situ (mm)	Distal resection Margin (mm)	Outcome after2.5 yr
1	Infiltrating	Poor	pT2N1M0	Mesorectum	LN	11	45	Disease free
2	Infiltrating	Poor	pT2N2M0	Submucosa	LN	8	33	Disease free
3	Mixed	Moderate	pT2N1M0	Mesorectum	LN	13	35	Local recurrence
4	Infiltrating	Moderate	pT3N2M0	MP	ly	10	40	Disease free
				Mesorectum	LN	25
5	Infiltrating	Moderate	pT2N0M0	Submucosa	D	7.5	40	Disease free
6	Infiltrating	Poor	pT3N1M0	Mesorectum	LN	36	38	Disease free
7	Mixed	Moderate	pT3N2M1	MP	D	5	25	Distant metastasis
				Mesorectum	LN	14
8	Infiltrating	Well	pT2N2M0	Mesorectum	ly	8	43	Disease free
9	Infiltrating	Moderate	pT2N0M0	Mesorectum	D	6	23	Disease free
10	Infiltrating	Moderate	pT3N2M0	MP	vi	4	28	Disease free
				Mesorectum	LN	9

¹According to the American Joint Committee on Cancer Staging Manual[14]; LN = lymph node metastasis; ly = lymphatic permeation; vi = vessel invasion; D = direct infiltration; MP = muscularis propria.