History
51 year-old asymptomatic woman presents for annual bilateral screening mammogram (LEFT side not shown.)

Diagnosis
Radial scar with sclerosing adenosis and luminal calcifications

Description of Findings

• Mammography shows an area of architectural distortion with associated pleomorphic calcifications in the right breast upper outer quadrant, middle to posterior depth. There is central lucency amidst the distortion.
• Ultrasound displays an irregular hypoechoic mass with an echogenic halo and posterior acoustic shadowing in the right breast at 10:30 o’clock axis, 5 to 6 cm from the nipple.
• Color Doppler imaging demonstrates flow adjacent to the hypoechoic mass.

Discussion
Radial scar is a benign lesion with imaging features that can mimic primary breast carcinoma. This lesion has been referred as complex sclerosing lesion (when >1-2 cm), sclerosing papillary proliferation, infiltrating epitheliosis, sclerosing duct hyperplasia, and benign sclerosing ductal proliferation. Radial scars are usually detected on screening examination in asymptomatic patients. Imaging alone is insufficient to distinguish a radial scar from carcinoma.

The classic mammographic appearance is an area of architectural distortion characterized by long spicules and central lucency, or an irregular mass with spiculated margins. Radial scar can have a variable appearance on different mammographic projections. When microcalcifications are present, they are associated with adenosis or atypical ductal hyperplasia (ADH). A correlate may not be detectable on ultrasound, but when present, radial scar appears as an irregular hypoechoic mass, with or without posterior acoustic shadowing. On MRI, radial scar appears as a spiculated enhancing mass indistinguishable from carcinoma.

Although radial scar is considered benign, there are reported associations with atypical ductal hyperplasia (ADH), ductal carcinoma in situ (DCIS) and tubular carcinoma. Therefore, when radial scar is diagnosed on core biopsy, complete surgical excision followed by histological examination is generally recommended. On histopathology evaluation, a radial scar appears spiculated, with long, thin connective tissue spicules coming off of a central point. Ducts near this lesion become distorted, exhibiting adenosis and epithelial proliferation.

References

1. Tabar, L., & Dean, P. B. (2001). Teaching Atlas of Mammography (Rev. ed.). New York, NY: Thieme
2. Kopans, D. B. (1998). Breast Imaging (2nd ed.). Philadelphia, PA: Lippincott-Raven Publishers
3. De Paredes, E. S. (2007). Atlas of Mammography (3rd ed.). Philadelphia, PA: Lippincott Wiliams & Wilkins

Case Contributed By
Anita Ahmed, MS
American University of Antigua

Biren A. Shah, MD
Henry Ford Hospital, Detroit, Michigan