Figure 7 Cytonuclear atypia in a columnar cell process. Note the apical snouts and columnar morphology, but in association with nuclei showing atypia in the form of mild pleomorphism, variation in shape, clumped chromatin and prominent nucleoli. The degree is insufficient for the diagnosis of flat high grade ductal carcinoma in situ (DCIS); lesions such as this also fall within the spectrum of flat epithelial atypia. Note the mitotic figure; these are unusual in flat epithelial atypia, as in atypical ductal hyperplasia/low grade DCIS.