Figure 2.

Three histological sections from one lesion. In our opinion, this lesion should be diagnosed as well-differentiated ductal carcinoma in situ (DCIS). These lesions are usually large (several centimetres in diameter). Well-differentiated DCIS often shows various growth patterns: clinging; micropapillary; cribriform. Every well developed cribriform DCIS [as shown in (c)] also contains areas with a clinging growth pattern (a). (a) Often diagnosed as columnar alteration with prominent apical snouts and secretions. (b) Often diagnosed as atypical ductal hyperplasia. These lesions are all in the spectrum of neoplasms characterized by a clonal proliferation of epithelial cells with monotonous round to oval nuclei, and for this reason they can best be classified as well-differentiated DCIS.