Assessment of likelihood of submucosal invasion in non-polypoid colorectal neoplasms.

Although of lower prevalence compared with polypoid neoplasms, the non-polypoid neoplasms, especially the depressed type, are important to diagnose because they belong to a distinct biologically aggressive subset, given the high rate of intramucosal or submucosal cancers. The detection and diagnosis of the non-polypoid colorectal neoplasm presents a challenge and an opportunity. Above all, characteristic colonoscopic findings obtained by a combination of conventional colonoscopy and magnifying chromoendoscopy are useful for determination of the invasion depth of non-polypoid colorectal cancers, an essential factor in selecting a treatment modality.