Endoscopy of Aberrant Crypt Foci: The Expert Approach

Aberrant crypt foci (ACF) were found to be possible precursors of adenoma and cancer, as well as useful surrogate lesions for chemoprevention of colorectal cancer. The aberrant crypts are stained more darkly with methylene blue and have a thicker epithelial lining and a larger pericryptal zone than normal crypts. Recently, advanced endoscopic imaging techniques have been found to be more helpful to improve detection and characterization of ACF in the colon. For inspection of ACF, optimal bowel preparation and a high-resolution endoscope equipped with a magnifying function is required. After spraying plenty of methylene blue, the mucosal surface should be washed with plenty of water to remove the sticky mucus. Once the dark blue spot is recognized with low magnification, zooming up to the maximum point should be performed. This article is part of an expert video encyclopedia.