Developing Asymmetry on Mammography

IMAGING FINDINGS:​

​Developing asymmetry in the superior right breast on screening mammograms from three consecutive years. Focally increased density lacks convex borders and 3-dimensional shape but increases in size and conspicuity over time. “A density appears where it used to be fat.” 

WHY IT MATTERS:

1. Relatively rare mammographic finding has a relatively high rate of malignancy. 
2. Identification of a developing asymmetry depends on assessing a change from prior studies. It can be very hard to pick out on a single exam but looking at multiple exams you can see a change.
3. The differential diagnosis for a developing asymmetry includes malignancy, trauma, weight change and PASH.

FURTHER READING:
Developing Asymmetries at Mammography: A Multimodality Approach to Assessment and Management (RadioGraphics, 2016)