My Doctor Discovered a Radial Scar in My Breast. What Does That Mean?

Finding a lump in your breast is frightening, and feeling anxious about it is normal. There are a number of breast conditions that can cause lumps. However, some conditions—like radial scars—go undetected until a breast procedure reveals them. We talked to the experts about these elusive lesions so that you have the information you need to be proactive with your breast health.

What is a radial scar?

A radial scar is not actually a scar, but rather a star-shaped breast mass that can be benign, precancerous or cancerous. Also referred to as complex sclerosing lesions (CSL), they are growths within the breast tissue that may look like scar tissue when viewed through a microscope—hence their name.

Kecia Gaither, M.D., M.P.H., F.A.C.O.G., director of Perinatal Services at NYC Health + Hospitals/Lincoln in the Bronx, explained that these lesions are known by several other names, including:

• Sclerosing papillary proliferation
• Indicative mastopathy
• Infiltrating epitheliosis
• Benign sclerosis ductal proliferation

Structurally, radial scars are made up of a central core that is fibrous in nature. They have two rows of cells: epithelial and myoepithelial. The "radial" part of their name comes from the way their peripheral borders (a series of tubular structures) radiate from the core, giving them a "black star" appearance on imaging tests. It's possible to have multiple radial scars in the same breast.

These structures are usually benign. However, they may indicate abnormalities in the breast tissue, including cystic conditions or epithelial hyperplasia, so it's important to have further testing to evaluate.

What causes radial scars?

Radial scars are considered a hyperplastic proliferative disease of the breast. They are the result of an overgrowth of abnormal cells within a person's mammary tissues.

While no precise cause has been identified for these lesions, some experts say they may be caused by localized inflammatory reactions (essentially involving a hyperreactive immune system) or chronic ischemia accompanied by slow infarction.

"These lesions are of unknown etiology and have been postulated to arise from a prior injury with the development of fibrosis and retraction," Gaither said.

This type of breast mass appears to be rare among younger women. A 2017 study published in the American Journal of Roentgenology stated that radial scars are uncommon in women under 30 and are usually found in women between the ages of 30 and 60.

Should I be concerned about radial scars?

Here's the thing: Most women don't even know they have radial scars. Typically, radial scars are too small to be noticed during breast self-exams or on mammograms.

"These are far too small to be detected on mammograms or even through self-examination," confirmed Tiffany L. Chan, M.D., an assistant clinical professor for Breast Imaging at the UCLA Department of Radiological Sciences. "Indeed, most radial scars are diagnosed via biopsy—and biopsies are usually mandated if the scars are big enough (6mm or larger) to be detected on a mammogram."

When they are big enough to be seen on mammography, they appear as a dense central core with thin spicules radiating out from the center. Skin changes or masses are not found with these lesions.

Radial scars bigger than 6 or 7 millimeters in width are the most likely to have either cancer cells or be the result of atypical hyperplasia or an overgrowth of abnormal cells.

While radial scars themselves are most often benign, a 2014 meta-analysis found they are associated with an increased risk of breast cancer. In 30 percent of radial scar cases, these lesions are associated with in situ ductal carcinoma and tubular carcinoma of the breast. The possibility of these conditions happening is higher if there are notable traces of cellular atypia in the tissues.

Radial scars bigger than 6 or 7 millimeters in width are the most likely to have either cancer cells or be the result of atypical hyperplasia or an overgrowth of abnormal cells. A core needle biopsy and additional tests may be used for further diagnosis.

Chan added that physicians recommend women who have been diagnosed with radial scars undergo mammograms more frequently than most, to err on the side of caution.

Treatment and prevention of radial scars

When a radial scar is large enough to be discovered on mammography, doctors recommend it be removed.

"Since the finding on sonography or mammography can't fully be differentiated from carcinoma, it's recommended that surgical incision be performed on all cases," Gaither explained.

For the most part, any surgical procedures for the removal of radial scars are done for prevention.

"Some patients would rather have these masses surgically excised even if cancerous cells aren't detected," Chan said. "Such removal entails either an open surgical biopsy or even a lumpectomy. Still, the procedure is dependent on how big a radial scar was found in the patient's breast."

Most women diagnosed with radial scars don't need to undergo any form of additional treatment. If the biopsy determines no atypical or invasive cells are present within the scar, there is no need for radiation, chemotherapy or hormone therapy.

Unfortunately, because it's unknown what causes radial scars, there isn't a known way to prevent them from forming. However, living a healthy lifestyle coupled with regular appointments with your healthcare provider is always recommended.

Breast health is a crucial point of concern for all women. Women with an increased cancer risk due to family history or the discovery of radial scars need to exercise vigilance. Mammograms and monthly self-examinations are instrumental in helping women detect any changes to their breasts that may prove life-threatening.