Histological appearance of<unk>  <unk>  and immunohistochemical phenotype: - A - One focus (- B - One area of an<unk>  with associated calcifications intraluminal. Hematoxylin and Eosin stain. - C - Higher magnification of<unk>  shows low-grade nuclear atypia and monotonous cell proliferation along with secondary intraluminal architecture. Hematoxylin and Eosin stain. - D - Strong and uniform expression of estrogen receptors (ER). ER immunohistochemistry. - E - Lack of basal cytokeratins (CK5/6). CK5/6 immunohistochemistry. It is diagnosed based on tissue, e.g. a biopsy, showing<unk><unk> . There is no single definite cutoff that separates<unk>  from<unk>  carcinoma in situ, but the following are important distinctive features of<unk> , with suggested cutoffs: *Size less than 2 mm. *Not involving more than one duct. *The<unk>  epithelial proliferation is admixed with a second population of proliferative cells without atypia. *The proliferation completely involves the terminal<unk>  lobular unit(s), to a limited extent.
Atypical ductal hyperplasia
Invasive lobular carcinoma
Ductal carcinoma in situ
Intraductal papilloma
Lobular carcinoma in situ
Fibroadenoma
Atypical hyperplasia
Focal nodular hyperplasia