NICE Classification for Colorectal Polyps

NICE Classification System Overview

The NICE classification categorizes colorectal polyps into three types: Type 1 (Serrated Class), Type 2 (Conventional Adenoma), and Type 3 (Deep Submucosal Invasive Cancer), as recommended by the Colon Tumor NBI Interest Group 1, 2
Type 1 polyps are characterized by a pale color, invisible vessels, and a regular surface pattern with dark or white spots 1, 2, 3, 4
Type 2 polyps are characterized by a brown color, regular caliber brown vessels surrounding white structures, and a regular tubular or branched/papillary surface pattern similar to surrounding mucosa 1, 2, 4
Type 3 polyps are characterized by a brown to dark brown color, disrupted or missing vessels, and an amorphous or absent surface pattern 1, 2, 4

The NICE classification can be used with or without magnification endoscopy and has been validated in multiple studies 1, 2, 5

The Kudo Pit Pattern Classification requires magnification colonoscopy with dye spray and classifies pits into 6 patterns (I, II, III-S, III-L, IV, V) 6, 3
The Japanese NBI Expert Team (JNET) Classification further subdivides Type 2 into 2A (low-grade intramucosal neoplasia) and 2B (high-grade intramucosal neoplasia/superficial submucosal invasive cancer) 4
Other classification systems, such as Hiroshima, Sano, Showa, Jikei, and BASIC, are used mainly in Asian countries and are not commonly employed in the United States 2, 5

Careful assessment of vessel pattern and surface pattern characteristics using NBI is essential for optimal use of the NICE classification 1, 2
Type 3 lesions are highly specific (although not sensitive) for deep submucosal invasive cancer 2

Interobserver agreement can be modest, especially among non-expert endoscopists 4