Breast Usual Ductal Hyperplasia

**Semantic type:** Neoplastic Process

**Definition:** A neoplastic ductal proliferative lesion of the breast characterized by the formation of secondary lumens and prominent intraductal proliferation of a heterogeneous cellular population that may include epithelial cells, myoepithelial cells, or metaplastic apocrine cells.

**Synonyms:** - Breast Hyperplasia without Atypia - Ductal Breast Hyperplasia of Usual Type - Ordinary Intraductal Breast Hyperplasia - UDH - Usual Ductal Breast Hyperplasia