Novel Endoscopic Findings as Visualized by Magnifying Endoscopy with Narrow-Band Imaging: White Opaque Substance Is Present in Colorectal Hyperplastic Polyps.

Background: Magnifying endoscopy (ME) with narrow-band imaging (NBI) can visualize a white opaque substance (WOS) in gastric epithelial neoplasms, gastric intestinal metaplasias, and colorectal epithelial neoplasms. Histological examination showed the WOS to be lipid droplets accumulated in the epithelium. The white appearance of colorectal hyperplastic polyps suggests that they may contain WOS, but this has not been investigated as yet. Aims: The purpose of this study was to determine whether WOS is present in colorectal hyperplastic polyps. Methods: We retrospectively evaluated endoscopic images of 26 consecutive lesions investigated by ME with NBI and subsequently endoscopically resected and confirmed to be hyperplastic polyps. Results: WOS was present in 21 of the 26 colorectal hyperplastic polyps (80.8%) based on the findings of ME with NBI. Adipophilin was present in 24 of the 26 colorectal hyperplastic polyps (92.3%). Conclusions: This study is the first to demonstrate that WOS (i.e. lipid droplets) accumulates in the epithelium of colorectal hyperplastic polyps. [ABSTRACT FROM AUTHOR]