Yield of upper gastrointestinal screening in colonic adenomatous polyposis of unknown etiology: a multicenter study.

 The majority of patients with 10 or more cumulative colorectal adenomas have uninformative genetic testing and meet criteria for colonic adenomatous polyposis of unknown etiology (CPUE). The yield of upper gastrointestinal screening in patients with CPUE after multi-gene panel testing is unknown and our objective was to characterize this.  A multicenter, retrospective analysis of screening upper endoscopies in adults with CPUE after multi-gene panel testing was performed.