Colon polyps-nomenclature, histology, and molecular pathology

Polyps are macroscopically visible protrusions of the mucosa in hollow organs. In the colon, epithelial neoplasms deriving from the mucosa dominate. These can be classified based on their morphology into classic and serrated adenomas and show different degrees of epithelial dysplasia. The histological subtypes show various molecular alterations and can be assigned to different pathways of carcinogenesis. These must be separated from hamartomatous polyps of the colon mucosa, which can occur sporadically or as part of hereditary syndromes.