What is dysplasia in the gastrointestinal tract?

Dysplasia in the gastrointestinal tract is considered both a carcinoma precursor and a marker of high cancer risk for the site at which it is found. Dysplasia is defined as unequivocally neoplastic epithelium, yet the specific criteria for making that determination are imperfectly defined. The current criteria actually include a mix of architectural and cytologic features, all of which occur in different intensities in different epithelia that are given the same diagnosis. Gastrointestinal dysplasias are divided into 2 grades, but there are problem areas in diagnosis at the lower end where low-grade dysplasias overlap with regenerating epithelia and in the middle where low- and high-grade dysplasias overlap. The diagnosis of dysplasia is too subjective with less than optimal reproducibility to be as useful a marker as needed. Pathologists need a dysplasia stain or a whole set of new markers of high cancer risk, presumably molecular and/or genetic, that are not dependent on pathologists' diagnoses of dysplasia and their inherent subjectivity.