Sporadic microsatellite instability-high colon cancers rarely display immunohistochemical evidence of Wnt signaling activation.

Most sporadic colonic adenocarcinomas are microsatellite stable (MSS) and arise from conventional adenomas by dysregulation of the APC/β-catenin/Wnt signaling pathway. Sporadic adenocarcinomas with a high degree of microsatellite instability (MSI) likely arise from sessile serrated polyps through th