Narrow-band imaging observation of colorectal lesions using NICE classification to avoid discarding significant lesions

Table 1 Narrow-band imaging International Colorectal Endoscopic Classification¹

	Type 1	Type 2	Type 3
Color	Same or lighter than background	Browner relative to background (verify color arises from vessels)	Brown to dark brown relative to background; sometimes patchy whiter areas
Vessels	None, or isolated lacy vessels may be present coursing across the lesion	Brown vessels surrounding white structures2	Has area(s) of disrupted or missing vessels
Surface Pattern	Dark or white spots of uniform size, or homogeneous absence of pattern	Oval, tubular or branched white structures surrounded by brown vessels2	Amorphous or absent surface pattern
Most likely pathology	Hyperplastic	Adenoma3	Deep submucosal invasive cancer
Treatment	Follow up	Polypectomy/EMR/ESD	Surgical operation

¹Can be applied using colonoscopes with or without optical (zoom) magnification;

²These structures (regular or irregular) may represent the pits and the epithelium of the crypt opening;

³Type 2 consists of Vienna classification types 3, 4 and superficial 5 (all adenomas with either low or high grade dysplasia, or with superficial submucosal carcinoma). The presence of high grade dysplasia or superficial submucosal carcinoma may be suggested by an irregular vessel or surface pattern, and is often associated with atypical morphology (e.g., depressed area).

Table 2 Clinicopathological feature

Total patient	468
Male/female	290/178
Mean age	66.3 (32-97, SD:)
Polyps	878
Mean size (mm)	4.7 (1-9, SD:)
Location (right side/left side)	542/336
Shape (pedunculated/sessile/ flat/depressed)	12/274/590/2
Histology
Non-neoplastic	123 (HP:100, SSA/P:13, other:10)
Adenoma	753 (TA:717, TVA:26, SA:10)
Grade (low/high)	711/42
Invasive cancer	2

HP: Hyperplastic polyp; SSA/P: Sessile serrated adenoma/polyp; TA: Tubular adenoma; TVA: Tubulovillous adenoma; SA: Serrated adenoma.

Table 3 Pathological evaluation using NICE classification

NICE classification	Non-neoplastic	Adenoma (low/high)	Invasive cancer
	Diminutive/small	Diminutive/small	Diminutive/small
NICE 1	42/12	11 (11/0)/9 (9/0)	0/0
NICE 2	63/6	564 (546/18)/169 (145/24)	0/0
NICE 3	0/0	0/0	1/1

NICE: NBI international colorectal endoscopic; Diminutive: 1-5 mm in diameter; Small: 6-9 mm in diameter.