Practical uses of chromoendoscopy and magnification at colonoscopy.

New technologies in the form of high-magnification or zoom colonoscopy complemented by chromoscopic agents permits early detection of neoplastic colorectal lesions, particularly flat and depressed types. Establishing suitability for endoscopic resection or surgical excision can be enhanced using these techniques. Chromoscopic colonoscopy may play an important role in the routine endoscopic colorectal cancer surveillance programs in patients assuming a high risk of colorectal neoplasia. This article summarizes recent data regarding the prevalence and histopathologic characteristics of flat and depressed colorectal lesion in Western cohorts and describes how their detection and management can be improved by chromoscopy and magnification technology. The techniques required for chromoscopic colonoscopy and magnification imaging are outlined along with a review of the literature on these subjects.