Sclerosing lesions of the breast

Sclerosis of the breast is an area of hardening of the breast tissue that can occur as the breast ages. Sclerosis is found in these benign (not cancer) breast conditions:

  • sclerosing adenosis
  • radial scar/complex sclerosing lesions.

What is sclerosing adenosis?

Breasts are made up of lobules (milk-producing glands) and ducts (tubes that carry milk to the nipple), which are surrounded by glandular, fibrous and fatty tissue. Sclerosing adenosis is a benign condition in which extra tissue grows within the breast lobules. It can cause recurring pain or result in a small, firm lump in the breast.

It is commonly seen as part of the normal aging process, especially in women in their 30s and 40s, but can occur at any age. Most women will not notice any symptoms and it is often only diagnosed during a routine mammogram (breast x-ray) or following investigation of an unrelated breast condition.


Sclerosing adenosis can be difficult to diagnose as on a mammogram it can sometimes look like breast cancer. Because of this, a biopsy may be needed to make a firm diagnosis. This may be done in a few ways:

Although sclerosing adenosis can often be diagnosed with a core biopsy, occasionally a small operation (excision biopsy) may be needed to remove the affected area and confirm that it is not breast cancer.

Follow up

Once a diagnosis has been confirmed as sclerosing adenosis, no further treatment is needed.

What are radial scars and complex sclerosing lesions?

Radial scars and complex sclerosing lesions are benign conditions (not cancer) that are essentially the same thing but are identified by size, with radial scars usually being smaller than 1cm and complex sclerosing lesions being more than 1cm. They are most common in women aged between 35 and 65.

A radial scar or complex sclerosing lesion is an area of hardened breast tissue. Most women will not notice any symptoms and these conditions are often only found on a routine mammogram or during investigation of an unrelated breast condition.

It may not be possible to clearly identify a radial scar and complex sclerosing lesion from a breast cancer on a mammogram. So your doctor may suggest you have a core biopsy, which removes small samples of breast tissue, to confirm the diagnosis. Sometimes they may suggest a vacuum assisted biopsy be done instead. See ‘Diagnosis’ (above) for more information about both these procedures.

Follow up

Even though the diagnosis can usually be made on a core biopsy, your doctor may suggest a small operation (excision biopsy) or a vacuum-assisted technique to remove the radial scar or complex sclerosing lesion completely. Once this has been done and confirmed as a radial scar, or a complex sclerosing lesion, no further tests or treatments will be needed.

Experts disagree as to whether having a radial scar or complex sclerosing lesion might mean a slightly increased risk of developing breast cancer in the future. Some doctors believe that any increase in risk is determined by what else is found in the tissue removed, for example, an area of atypical hyperplasia.

Content last review November 2012; next planned review 2014