Early colorectal cancer: concept, diagnosis, and management.

In colorectal cancers, although flat and depressed-type lesions are found by regular endoscopic view, magnification and pit-pattern observation are vital parts of the precise diagnosis of the lesion. The depressed-type lesions appear to have a prominent tendency to show malignant characteristics, and the recognition and timely treatment of such lesions is important for improving the morbidity and mortality of colorectal cancer. Chromoscopy is mandatory for an accurate diagnosis of these lesions. The pit-pattern classification correlates well with actual histological findings and can provide important additional information prior to endoscopic treatment of the lesion.