Figure 4 Lesion composed of a peripheral population formed from columnar cells with apical snouts. However there is architectural atypia in the form of rudimentary cribriform spaces. In the central portion of the space, the epithelial cell nuclei are more rounded and uniform and show mild cytological atypia. Lesions with such features should be classified within the spectrum of atypical ductal hyperplasia/low grade ductal carcinoma in situ, depending on extent of the process.