breast ductal adenocarcinoma (Monarch Disease Ontology id MONDO_0005590) is a breast carcinoma arising from the ducts. While ductal carcinomas can arise at other sites, this term is universally used to refer to carcinomas of the breast. Ductal carcinomas account for about two thirds of all breast cancers. Two types of ductal carcinomas have been described: ductal carcinoma in situ (DCIS) and invasive ductal carcinoma. The latter often spreads to the axillary lymph nodes and other anatomic sites. The two forms of ductal carcinoma often coexist. Also known as: breast ductal carcinoma, ductal breast adenocarcinoma, ductal breast carcinoma, ductal carcinoma of breast, ductal carcinoma of the breast, mammary duct adenocarcinoma.