Columnar Cell Change of the Breast with Atypia

**Semantic type:** Neoplastic Process

**Definition:** A columnar cell lesion characterized by the presence of enlarged terminal ductal lobular units with dilated acini. The acini are lined by one or two layers of columnar epithelial cells. Cytologic atypia is present.

**Synonyms:** - Columnar Cell Change of Breast with Atypia - Columnar Cell Change with Atypia