A radial scar is a form of sclerosing duct hyperplasia. There is typically no solid, dense central tumor corresponding to the size of the spicules. But, often there are translucent, circular, or oval regions in the center of the radiating structure which gives the radial scar a characteristic 'star-like' appearance. Radial scars may indicate a disturbance in the breast tissue and more specifically between the stromal (supportive)and functional elements (lobules, ducts, etc), that can lead to the formation of scar tissue, or possibly to cancer.
A radial scar moderately increases risk of breast cancer development
A finding of a radial scar is thought to be an increased risk factor for breast cancer. Women with a radial scar are thought to be at higher risk for breast cancer development, ranging from approximately 8% to 30%.
Radial scars are not seen on ultrasound
At mammography they may be detected as a kind of star-shaped feature with spiculated contours and no or little central mass. They are not detectable using ultrasound, and they are usually confirmed during biopsy.
The image below is a mammogram of a radial scar.
Biopsy is required for confirmation and differantial diagnosis
The spiculated, star-like configuration of the radial scar can resemble tubular carcinoma, so to establish a differential diagnosis, a biopsy is taken examined under a microscope. Typically one of two stains is applied to the tissue: either hematoxylin-eosin or immunohisotchemical actin. A finding of healthy myoepithelial cells in the histological workup exludes the diagnosis of tubular carcinoma.
Differntial diagnosis: ruling out tubular carcinoma by biopsy
The images below are histology slides of breast tissue, and show benign ducts within a sclerotic stroma, thus ruling out the possibility of tubular carcinoma. The breast tissue in both of these images has much thicker collagen (fibrous tissue ), than average, and would in fact feel much harder too the touch than normal.
Hematoxylin-eosin, and staining actin
Hematoxylin-Eosin is a type of stain, applied to the tissue, which makes things look a certain way under the microscope.
The second image uses a stain called 'staining-actin', often used to find smooth muscle tissue (actin).The actin stain shows the smooth muscle as the darker-brown color where muscle cells are lining the outside of ducts (tubules).
In both images above, the absence of any kind of abnormality affecting the epithelial lining of the tubules rules out tubular carcinoma, and confirms the diagnosis of radial scar.
Excisional biopsy reduces 'false negatives'
There is some danger of 'false negative' finding if the biopsy is done with very small samples, such as by fine needle aspiration or a needle core biopsy. In it not uncommon for a radial scar or complex sclerosing lesion to contain small amounts of malignant breast cancer cells. An excisional biopsy is usually recommended.
- Jacobs, TW et al. Abramson Cancer Center of the University of Pennsylvania .The New England Journal of Medicine Vol. 340 No. 6 p.430 February 11, 1999
- Tabar, Laszlo. M.D. Teaching Course in diagnostic breast imaging: Multimodality approach to the detection and diagnosis of occult breast cancer. Mammography Education, Inc. 2001.
- Mokbel, K., Price, R.K., Carpenter, R., Jacobs, T. W., Connolly, J. L., Schnitt, S. J. (1999). Radial Scars and Breast Cancer. NEJM 341: 210-210
- Brenner, R. J., Jackman, R. J., Parker, S. H., Evans, W. P. III, Philpotts, L., Deutch, B. M., Lechner, M. C., Lehrer, D., Sylvan, P., Hunt, R., Adler, S. J., Forcier, N. (2002). Percutaneous Core Needle Biopsy of Radial Scars of the Breast: When Is Excision Necessary?. Am. J. Roentgenol. 179: 1179-1184
- Douglas-Jones, A., Denson, J., Cox, A., Harries, I., Stevens, G., Radial scar lesions of the breast diagnosed by needle core biopsy: analysis of cases containing occult malignancy. J Clin Pathol 2007;60:295-298
Copyright Steven B. Halls, MD Last edited 14-August-2011