ductal breast hyperplasia (EFO_0008500) is hyperplasia of the epithelial cells in the breast ducts. It includes the atypical ductal hyperplasia, papillary intraductal hyperplasia, intraductal myoepitheliosis, and ductal hyperplasia of the usual type. Also known as: breast epithelial hyperplasia, ductal hyperplasia of breast, ductal hyperplasia of the breast, epithelial hyperplasia of breast, epithelial hyperplasia of the breast.