title: Prevalence and clinicopathological features of nonpolypoid colorectal neoplasms: should we pay more attention to identifying flat and depressed lesions?
abstract: Flat and depressed (nonpolypoid) colorectal lesions have been described for over two decades by Japanese investigators. These neoplastic lesions are typically smaller than polypoid ones and can be more difficult to identify during screening colonoscopy. In particular, depressed type colorectal lesions are usually small in size, with a number of studies showing them to be at greater risk for developing high-grade dysplasia or submucosal invasive cancer. It has also been suggested that they may follow a different carcinogenic pathway to flat elevated or protruding adenomas. This paper summarizes recent data of nonpolypoid colorectal neoplasms from Western and Asian countries.
authors.affiliation: Endoscopy Division, National Cancer Center Hospital, Tokyo, Japan. tamatsud@ncc.go.jp
authors.forename: Takahisa
authors.initials: T
authors.lastname: Matsuda
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Saito
authors.forename: Kinichi
authors.initials: K
authors.lastname: Hotta
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Sano
authors.forename: Takahiro
authors.initials: T
authors.lastname: Fujii
mesh_terms: D003111:Colonic Polyps; D003113:Colonoscopy / Q000379:methods*; D015179:Colorectal Neoplasms / Q000453:epidemiology / Q000473:pathology*; D003937:Diagnosis, Differential; D014943:Global Health; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology*; D015995:Prevalence