The superolateral margin of the glandular disc is one of the review areas on mammography. You should train your eye to review this area and together with the prepectoral fat, you should consciously scan this area on review. This way you will pick up subtle density and parenchymal changes. This patient had a normal clinical exam. The tumor was easily seen on ultrasound.
Gary Player said of golf: the more I practice, the luckier I get. The same is true of mammography.