[Sessile serrated adenoma: an underdiagnosed colonic polyp]

Serrated polyps of the colon represent a large morphological spectrum of lesions. They comprise the hyperplastic polyp considered as an innocuous lesion for many years, the traditional serrated adenoma presenting a potential of cancerisation and the recently described the sessile serrated adenoma which seems to be a potential precursor of colonic cancer with microsatellite instability and which probably uses an alternate polyp-neoplasia pathway in addition to the classical adenoma-carcinoma sequence. The aims of this article intend to inform of new concept of colonic carcinogenesis, to be aware of a serrated colonic polyp entity recently described and to use a same nomenclature to facilitate the dialogue between pathologists and clinicians.