What is intraductal papilloma from?

Sometimes. It's called id papillary adenocarcinoma...The importance is whether it invades or confined to duct, and whether the margins are clear. These are analgous to dcis, usually er/pr+. They have excelent 5 and 10 year prognosis..Close to 100% survial, but it is when they are harbingers of invasive cancers that there are threats to life and breast. There are no clear causes.