Breast Lobular Neoplasia

**Semantic type:** Neoplastic Process

**Definition:** A spectrum of non-invasive neoplastic lesions that arise from the terminal ductal lobular units of the breast. There is atypical small epithelial cell proliferation. Pagetoid involvement of the terminal ducts may or may not be present. In the minority of cases, there is a risk for subsequent development of invasive ductal or invasive lobular carcinoma.

**Synonyms:** - Breast LN - LIN - LN - Lobular Intraepithelial Neoplasia - Lobular Neoplasia - Lobular Neoplasia