The history of modern medicine is riddled with stories of discovery,
skepticism, rejection, and, sometimes, redemption and acceptance.
For instance, the discovery of Helicobacter pylori by Marshall1 is a fairly recent example of initial rejection by the mainstream scientific community and ultimate redemption (as recognized by the Nobel Prize).
Similarly, reports from Japan in the 1980s and 1990s suggested that nonpolypoid (ie, flat or depressed) colorectal neoplasms (NP-CRNs)
were common and ominous.2,3 Depressed lesions commonly harbored in situ or submucosal carcinoma.
However, some western investigators were skeptical because such lesions were not commonly found in North American patient populations, and the rates of high-grade dysplasia in small flat polyps were low.4,5 In 1992, a prospective study from Nebraska found that although flat adenomas could be found with careful examination, none contained high-grade dysplasia.6 Subsequent studies from Sweden,7 Canada,8 the United States,9 and the United Kingdom10 reported that with careful examination technique,
flat and depressed lesions were indeed found in the West. Even though there was agreement that flat lesions are difficult to detect and might easily be missed with routine colonoscopy, the importance of such findings in the West remained uncertain but of concern.