Sclerosing adenosis of the breast

by Jason Wasserman MD PhD FRCPC
November 19, 2023


Sclerosing adenosis is a non-cancerous growth made up of small glands in the breast. The glands are surrounded by a type of connective tissue that resembles a scar. When large enough, this type of growth can be seen in imaging studies such as mammography, and a biopsy may be performed to rule out cancer.

What are the symptoms of sclerosing adenosis?

Sclerosing adenosis alone rarely causes any symptoms and usually cannot be felt as a discrete lump in the breast. This condition is often only detected after imaging such as mammography.

What causes this condition?

At present, we do not know what causes sclerosing adenosis.

Is sclerosing adenosis associated with an increased risk of developing breast cancer?

A person with sclerosing adenosis has a 1.5 to 2-fold increased lifetime risk of developing breast cancer compared to a person without this condition.

How is this diagnosis made?

This diagnosis is made after tissue is examined under a microscope by a pathologist. The tissue often comes from a biopsy performed to investigate an abnormal area in the breast. However, this condition is also commonly an incidental (accidental) finding in breast tissue removed to treat another condition such as breast cancer.

What does sclerosing adenosis look like under a microscope?

When examined under a microscope, this condition is made up of round structures called glands arranged in groups called lobules. The glands are often surrounded by a dense connective tissue called collagen that resembles a scar. Small deposits of calcium called microcalcifications are commonly seen both within the glands and the connective tissue.

About this article

This article was written by doctors to help you read and understand your pathology report. Contact us if you have any questions about this article or your pathology report. Read this article for a more general introduction to the parts of a typical pathology report.

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Other helpful resources

Atlas of Pathology
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