Serial mammograms of the right breast over five years. There is a developing asymmetry in the right breast. Notice the gradual increase in density in the upper outer right breast without an obvious mass. It is difficult to appreciate an abnormality on any given year, however comparison with multiple prior studies reveals a definite change.
WHY IT MATTERS:
The Developing Asymmetry: Revisiting a Perceptual and Diagnostic Challenge (RSNA 2015)