Table 2: NICE classification.

Type 1Type 2Type 3

Color Same or lighter than backgroundBrowner relative to background (verify color arises from vessels)Brown to dark brown relative to background; sometimes patchy whiter areas

VesselsNone, or isolated lacy vessels may be present coursing across the lesionBrown vessels surrounding white structures**Has area(s) of disrupted or missing vessels

Surface patternDark or white spots of uniform size, or homogeneous absence of patternOval, tubular or branched white structures** surrounded by brown vessels Amorphous or absent surface pattern

Most likely pathologyHyperplasticAdenoma***Deep submucosalinvasive cancer

TreatmentFollowupPolypectomy/EMR/ESDSurgery

*Can be applied using colonoscopes with/without optical (zoom) magnification.
**These structures (regular or irregular) may represent the pits and the epithelium of the crypt opening.
***Type 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).