Radial Scar of the Breast: Understanding Your Pathology Report

by Kimberly Wood, MD MSc FRCPC
August 13, 2026

A radial scar is a noncancerous (benign) growth in the breast made up of an increased number of glands and ducts arranged around a central area of scar-like tissue. Under the microscope, the glands appear to radiate outward from this center like the spokes of a wheel, which is where the name comes from. Despite the name, a radial scar is not a true scar and does not develop after an injury or surgery.

When a radial scar is larger, usually more than 1 cm, it is often called a complex sclerosing lesion. Both names describe the same type of growth, and which one appears on your report depends on the size of the lesion and the pathologist’s preference. A radial scar cannot spread to other parts of the body. It matters for two reasons: it can look very much like breast cancer, and it is associated with a small increase in future breast cancer risk. This article will help you understand the findings in your pathology report, what each term means, and why it matters for your care.

What are the symptoms of a radial scar?

Most radial scars cause no symptoms and are found incidentally when breast tissue is examined for another reason. Rarely, a radial scar becomes large enough to be felt as a lump. Larger radial scars may be seen on screening mammography or ultrasound, where they typically appear as an area with strands of tissue radiating outward from a center, a pattern that closely resembles breast cancer on imaging.

What causes a radial scar?

The exact cause of a radial scar is not known. It is believed to develop as part of the breast’s long-term response to normal processes within the tissue, and it is not caused by injury, surgery, or anything a person did. Radial scars are often found alongside other benign changes grouped under fibrocystic change.

How is the diagnosis made?

A radial scar is diagnosed after breast tissue is examined under the microscope by a pathologist. The tissue usually comes from a core needle biopsy performed because an abnormal area was seen on imaging, or from a larger sample removed by surgery. For many people, a radial scar is found incidentally when a biopsy or surgery is done for another reason.

Under the microscope, a radial scar has a central core of dense connective tissue that pathologists describe as fibrosis. The report may also describe this tissue as elastotic or showing elastosis, meaning it contains a large amount of a stretchy material called elastic fiber. Small, irregularly shaped ducts and glands are trapped within this central core, and ducts and glands radiate outward from it. Other benign changes are commonly seen in the surrounding tissue, including usual ductal hyperplasia, cysts, sclerosing adenosis, and apocrine metaplasia.

Because the trapped glands sit within scar-like tissue, a radial scar can closely resemble invasive ductal carcinoma under the microscope, just as it resembles cancer on imaging. The feature that separates them is the presence of myoepithelial cells, a supporting layer of cells that surrounds normal glands and is preserved in a radial scar but lost in invasive cancer. When the distinction is difficult, the pathologist performs immunohistochemistry (IHC) to highlight these cells and confirm the growth is benign.

Does a radial scar increase the risk of breast cancer?

A radial scar is associated with a modest increase in the lifetime risk of developing breast cancer, roughly 1.5 to 2 times that of a person without one. The overall risk remains low, and most people with a radial scar never develop breast cancer. The level of risk is higher when an atypical change, such as atypical ductal hyperplasia, is found within or near the radial scar. Because the increased risk applies to the breast tissue generally, follow-up considers both breasts rather than only the area where the radial scar was found.

What happens after this diagnosis?

Because a radial scar can hide more advanced changes within it, the main goal after diagnosis is to confirm that nothing more serious is present. The pathology findings, together with your imaging, guide what your team recommends.

Surgical excision — Removing the radial scar is often recommended when it is diagnosed on a core needle biopsy. This is because examining the whole area sometimes reveals atypical ductal hyperplasia, ductal carcinoma in situ, or a small cancer that the needle did not capture.
Observation — When a small radial scar is found incidentally, contains no atypical changes, and the biopsy result matches the imaging, close follow-up with examination and imaging may be recommended instead of surgery.
Routine screening — Your doctor will discuss the right breast screening schedule based on your overall risk factors.

Questions to ask your doctor

Was the radial scar the only finding, or were other changes also present?
Were any atypical changes, such as atypical ductal hyperplasia, found within or near the radial scar?
Did my biopsy result match my imaging findings?
Do I need surgery to remove the area, or is close follow-up enough in my case?
If it was removed, was anything additional found once the whole area was examined?
How much does this finding change my future risk of breast cancer?
Does the increased risk apply to both breasts?
What breast screening schedule do you recommend for me?