Source:http://linkedlifedata.com/resource/umls/id/C1333324
NCI: Epithelial dysplasia that develops in Barrett esophagus. It is classified as low or high grade. When technical reasons make the interpretation of atypia difficult, atypia is present but it is not quite to the level of dysplasia, or atypia is present at the bases of the crypts but does not reach the surface of the crypts, then the diagnosis of Barrett esophagus-indefinite for dysplasia is made.