| This section deals with those epithelial abnormalities which
are not neoplastic but which need to be distinguished from neoplasia. It
includes the hyperplasias, the metaplasias, the epithelial changes which
are secondary to inflammation or chronic irritation (reactive atypia) and
those that result from therapy (treatment effects). Lastly, there are the
borderline cases in which the epithelium is not normal but a clear
distinction cannot be made between reactive atypia and low grade neoplasia
(atypia of uncertain significance). |
