[Endocytoscopy in the colorectum]

Endocytoscopy (EC; Olympus), which involves a contact light microscopy system (380- or 450-fold) on the distal tip of a colonoscope, is a novel emerging endoscopic system. EC enables prediction of the lesion histology or the depth of a cancer by on-site observation of both structural and cytological atypia. According to the retrospective analysis of 514 colorectal lesions observed with use of EC, the diagnostic accuracy of differentiating neoplastic change was 96.5%, while that of differentiating massively invasive submucosal cancers was 96.3%. In this article, we report the usefulness of EC focusing on the EC classification which classifies colorectal lesions on the basis of EC findings.