Comedocarcinoma is one kind of very early-stage breast cancer which demonstrates central necrosis. It is a type of ductal carcinoma in situ. Comedo carcinomas are non-infiltrating and intraductal tumors.
The duct will have characteristic necrotic tissue with calcification that feels cord-like. Squeezing the duct will yield inspissated material that is cheesy-like and similar in consistency to toothpaste.
This article incorporates public domain material from the U.S. National Cancer Institute document "Dictionary of Cancer Terms".