Benign sclerosing lesions include radial scars and complex sclerosing lesions. Radial scars are are always ≤10 mm while complex sclerosing lesions are >10 mm. They exist as an area of hardened tissue in the breast that is usually first seen on mammogram. The term “radial scar” was coined by Dr. Hamperl in 1975. Prior to this, Semb had described the lesion in 1928 as a “rosette-like” lesion.
Pathogenesis
- Originate at the point of the terminal duct branching
- Contains fibrosis flecked by elastic streaks with firm central fibroelastic core
- Intact myoepithelial layer
Presentation
- Asymptomatic → often first seen on imaging
- Larger lesions may be palpable
- ± Breast skin dimpling
Imaging
- Mammogram
- Irregular spiculations in surrounding stroma → may look similar to carcinomas
- Distinguishing feature: has hollow center (cancer is solid mass in the center of the lesion)
- Histology: microcysts, epithelial hyperplasia, adenosis; prominent display of central sclerosis; central fibroelastic core with ducts and lobules radiating outward
Treatment
- Observation
- Annual clinical breast exam and mammogram
- Growth of lesion or change → excision
- Surgery
- Warranted if findings are discordant or high-risk lesion is present
Relevant Information
- Associated with 2x increase risk for breast cancer
- Easily confused as cancer on mammography due to spiculated pattern
- Complex sclerosing lesions used to be called a radial scar. The only difference between the two is that a complex sclerosing lesion is >10 mm and a radial scar is ≤10 mm.