This review, based on the content of the 2020 US Gastrointestinal Pathology Society's Rodger Haggitt Lecture, concerns an array of tubular gastrointestinal tract dysplastic or possible "predysplastic lesions" with an almost purely morphologic focus based on our collaborative efforts over the past few years. These processes include esophageal epidermoid metaplasia, Barrett esophagus-associated dysplasia, polypoid gastric dysplastic lesions, small intestinal dysplasia, and the ability of metastases to mimic it, the controversial "serrated epithelial change" encountered in the setting of long-standing ulcerative and Crohn colitis, and recently described anal columnar human papilloma virus-associated neoplasms
