Adenosis

In adenosis, the breast lobules are enlarged, and they contain more glands than usual. Adenosis is often found in biopsies of women with 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, this condition is benign and 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) may form in adenosis, in sclerosing adenosis, and in cancers. These can be confusing on mammograms.

Because adenosis can often be confused with cancer based on breast exams or mammograms, a biopsy is usually needed to tell them apart. Fine needle aspiration (FNA) biopsy of these lumps can usually show if they are benign. A core needle biopsy can usually identify the mass as adenosis, but sometimes a surgical biopsy is needed to be sure it is not 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.