The aim of this article is to introduce the term flat neoplastic lesion. This type of neoplasia is quite often errorneously described as sessile polyp from which differs geneticaly. In comparison with polyps, it is also more difficult to detect flat lesions and to treat them. Unsufficent attention of western endoscopits could be one of the reasons of interval cancers development.

        Key words: Flat neoplastic lesion, colorectal cancer, endoscopic polypectomy.