Radial scar of the breast

by Kimberly Wood, MD MSc FRCPC
November 19, 2023

A radial scar, also known as a complex sclerosing lesion, is a non-cancerous growth in the breast characterized by an increased number of glands and ducts around a central scar. Although non-cancerous, this condition is associated with a small increased risk of developing breast cancer when compared to women without radial scars.​

What are the symptoms of a radial scar?

Most radial scars in the breast do not cause any symptoms and the growth is found incidentally when imaging of the breast is performed for other reasons. Rarely, the growth becomes large enough to be felt as a lump in the breast.

What causes a radial scar of the breast?

At present doctors do not know what causes this condition to develop.

How is this diagnosis made?

Radial scars can be diagnosed after a small sample of tissue is removed in a procedure called a biopsy. The diagnosis can also be made after a larger area of tissue is removed in a procedure called a resection. For many patients, a radial scar is discovered incidentally after a biopsy or resection is performed for another reason. However, some radial scars can be seen on screening mammography/ultrasound, especially when they are greater than 1 cm in size. Because a radial scar can look very similar to breast cancer on mammography or ultrasound, a biopsy is performed to confirm the diagnosis.

What does a radial scar look like under the microscope?

When examined under the microscope, a radial scar is made up of abnormal connective tissue that pathologists describe as fibrosis. The abnormal connective tissue is sometimes described as showing elastosis or being elastotic because it contains numerous elastic fibers. Small irregularly shaped ducts and glands are often seen trapped within the area of fibrosis. Other non-cancerous changes that are often seen in the tissue surrounding the growth include usual ductal hyperplasia (UDH), cysts, and apocrine metaplasia.

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.

Related articles

Usual ductal hyperplasia (UDH)

Fibrocystic change

Columnar cell change

Other helpful resources

Atlas of Pathology