Pit Pattern in Colorectal Neoplasia: Endoscopic Magnifying View

In vivo studies of the micro structure of the mucosal surface began in stomach diseases earlier than in colonic diseases, but a clear magnified image is difficult to obtain, because the gastric mucosa is often too damaged by gastric acid and/or inflammation in relation to Helicobacter pylori infection. In contrast, a normal colon is usually free of inflammatory changes, thus suitable for magnified observation. The surface micro structure of colorectal epithelium was first analyzed using dissecting microscopes on resected specimens in the 1970s. The surface morphology in normal rectal mucosa was described by Bank et al. 1, and subsequent investigations have demonstrated structural alterations in colorectal epithelial neoplasms. In the early 1980s Nishizawa et al. 2 stressed that the normal colonic mucosa, adenoma, and adenocarcinoma showed their own characteristic surface structures. Kawano et al. analyzed the stereomicroscopic pit pattern of depressed colorectal carcinoma 3. The development of magnifying fiber colonoscopes in the 1980 s enabled the micro structure of the various colorectal lesions to be seen in vivo 4. The advent of commercially available highresolution magnifying video colonoscopes (up to x 100) in the 1990 s accelerated the study of the microstrucrures of colonic lesions 5 6 7 . The combination of chromoscopy and magnifying colonoscopy is useful for detecting small localized lesions, for differential diagnosis, and for determining not only the lateral extent but also the depth of a lesion. Some investigators have also reported the analysis of the diffuse mucosal changes in inflammatory bowel diseases using magnifying colonoscopes.