Radial scars are often detected in screening mammography (0.9 per 1,000 women screened) or as incidental findings in excision breast biopsy for another pathology. Their importance lies in that they may mimic carcinoma.
Typically, a radial scar will appear as an area of distortion with long radiating strands and a small mixed-density center (compared with a typical carcinoma, which has short spicules and a dense center). Associated fine granular calcification is common. The features of a radial scar and a carcinoma frequently overlap, however, making reliable distinction impossible.
Radial scars often appear as distorted areas of architecture with no definite mass lesion. Again, distinction from a carcinoma is unreliable.
The sliced lesion has a stellate outline, firm consistency, often with central puckering, and white color with yellow elastotic foci, which are usually centrally placed. The size can vary from a few millimeters to several centimeters. The larger lesions are sometimes termed complex sclerosing lesions.
Characteristically the lesion has a dense, sclerotic center with foci of elastosis and scattered flattened and angulated tubules lined by an inner epithelial and an outer myoepithelial layer. Radiating from this central sclerotic area are bands of less dense fibrous stroma that contain ductal and acinar structures showing a range of changes that include florid epithelial hyperplasia, blunt duct adenosis, sclerosing adenosis, apocrine metaplasia and papilloma formation. In a small number of cases, particularly those larger than 10 mm, atypical hyperplasia of ductal or lobular type may be seen.
Very occasionally in situ carcinoma is detected in these lesions.
Surgical excision by mammographic localization of the lesion is recommended in order to exclude an underlying carcinoma. There is no clear evidence for an increased risk of breast cancer in patients who have been treated for a radial scar.
A.D. Purushotham, P. Britton and L. Bobrow
A prospective study of benign breast disease and the risk of breast cancer. JAMA 2002