Most sporadic FGPs have beta-catenin mutations [111] but very rarely contain dysplasia, whereas FGPs in patients with FAP contain a APC-mutation and dysplastic FGPs often contain a second hit APC mutation, but no beta-catenin mutation, which is believed to cause dysplasia and a risk of adenocarcinoma development. This evidence concerns the gene CTNNB1 and adenocarcinoma.