Ductal carcinoma in situ SNOMEDCT_US:109889007 SNOMEDCT_US:373176000 SNOMEDCT_US:86616005 SNOMEDCT_US:278053004 UMLS:C0007124 Presence of abnormal cells inside a milk duct, that is, non-invasive breast cancer. Ductal carcinoma in situ is considered to be a precursor lesion to invasive breast cancer. Neoplasm of the breast