Non-Cancerous Breast Conditions

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In adenosis the breast lobules are enlarged, and they contain more glands than usual. Adenosis is often found in biopsies of women who have fibrocystic changes. There are many names for this condition, including aggregate adenosis, tumoral adenosis, or adenosis tumor. Even though some of these terms contain the term tumor, adenosis is not a cancer.

Sclerosing adenosis is a special type of adenosis in which the enlarged lobules are distorted by scar-like fibrous tissue.


If many enlarged lobules are close to one another, they may be large enough to be felt. When this is the case, it may be hard for the doctor to tell these lumps from a breast cancer with only a breast exam. Calcifications (mineral deposits) can form in adenosis, in sclerosing adenosis, and in cancers. These can be hard to tell apart on mammograms, so a biopsy is usually needed to know if they’re caused by adenosis or cancer. (In a biopsy, tissue is removed and checked under a microscope.)


Women with adenosis do not need treatment, but might be watched closely.

How does adenosis affect your risk for breast cancer?

Some studies have found that women with sclerosing adenosis have a greater risk of developing breast cancer – about 1½ to 2 times the risk of women with no breast changes.

Last Medical Review: 03/16/2015
Last Revised: 04/21/2016