A radial scar, also known as a complex sclerosing lesion, is a benign breast finding often detected during routine imaging. Although non-cancerous, its appearance on a mammogram can closely mimic aggressive breast cancer, causing concern. Clinical intervention is usually required to ensure a precise diagnosis and address associated risks. This article explores the nature of the radial scar, its management, and the likelihood of its reformation after treatment.
What Defines a Radial Scar
A radial scar is a benign proliferative breast lesion characterized by a central core of dense, fibrous tissue. This core pulls surrounding milk ducts and lobules inward, creating a distinctive stellate, or star-like, configuration. If the lesion measures larger than 1 centimeter, it is called a complex sclerosing lesion.
These lesions are typically asymptomatic and not palpable during a physical examination. Radial scars are usually discovered incidentally during a screening mammogram because their spiculated borders create an architectural distortion. Since this distortion is indistinguishable from invasive carcinoma on imaging, a tissue biopsy is always necessary to confirm the exact nature of the lesion.
Assessing the Associated Cancer Risk
The radial scar itself is benign and does not become cancerous. Its presence is significant because it is frequently intertwined with other high-risk lesions, such as atypical hyperplasia or ductal carcinoma in situ (DCIS), which may not be fully sampled during the initial core biopsy. These associated high-risk lesions, like atypical ductal hyperplasia (ADH), elevate a patient’s long-term risk of developing breast cancer.
Studies show that a radial scar is associated with atypia or malignancy in up to 30% of cases upon surgical removal. The presence of atypia is particularly important, as it significantly increases the risk of a cancer “upgrade” found upon complete excision. Therefore, the clinical decision to remove the scar is driven by the necessity of fully evaluating the entire area for these higher-risk components.
Standard Approach to Treatment
The clinical consensus for managing a radial scar found on core needle biopsy is often surgical excision, or lumpectomy. This intervention’s primary purpose is to obtain a complete tissue sample for thorough examination. This ensures no coexisting high-risk lesions or malignancy were missed by the initial needle biopsy. The goal is to remove the entire lesion with clear margins, meaning no abnormal cells remain at the edges of the removed tissue.
Evolving Management
The management of a pure radial scar without associated atypia found on a high-volume vacuum-assisted biopsy (VAB) is evolving. For smaller lesions (under 1 cm) that were well-sampled and show no atypia, some centers consider imaging surveillance as an alternative. However, surgical excision remains the standard practice in many settings, especially if the lesion is large or if the initial biopsy sampling was suboptimal.
Understanding Recurrence and Monitoring
The question of whether a radial scar can “come back” after complete removal with clear margins requires separating the scar itself from the underlying risk. True recurrence of the exact radial scar tissue in the same spot is uncommon following successful surgical excision. Since the lesion results from localized tissue changes, it is not expected to simply reform in that precise location.
However, patients remain at a slightly elevated lifetime risk for developing new proliferative lesions, including other radial scars or malignancies, in either breast. This is because the radial scar manifests underlying tissue characteristics that affect the entire breast. The risk of developing a new cancer is related to the overall breast environment and any coexisting atypical changes found in the excised tissue.
Continued surveillance is mandatory post-treatment due to this heightened overall risk. Monitoring protocols typically involve increased frequency of mammograms, sometimes supplemented with breast ultrasound or MRI. This long-term follow-up detects new, unrelated lesions or developing malignancies early, rather than looking for the return of the original radial scar.