Breast Classic Lobular Carcinoma In Situ

**Semantic type:** Neoplastic Process

**Definition:** Breast lobular carcinoma in situ characterized by the presence of dyscohesive proliferations of type A and/or type B epithelial cells. Type A cells are small cells with uniform hyperchromatic nuclei, whereas type B cells have slightly larger vesicular nuclei, with mild variability in size and shape and with small nucleoli. The cell populations may be mixed in individual proliferations. (WHO 2019)

**Synonyms:** - Breast Classic LCIS