β-catenin Helices in the cytoplasm of sporadic and FAP duodenal adenomas.

Background: Initiation and progression in conventional adenomas is triggered by deregulation of Wnt/β-catenin signaling. In the absence of Wnt signal (off-state), β-catenin prevents phosphorylation of glycogen synthase kinase (GSK)-3β leading to aberrant nuclear accumulation in human tumors. While investigating the nuclear expression of β-catenin in biopsies from duodenal adenomas, we observed a non-previously reported phenomenon, namely the presence of β-catenin cytoplasmic helices (coils).