For example, a fibroadenoma containing a large calcification may demonstrate shadowing posterior to the calcified area but enhancement of the tissues deep to the uncalcified portion. A combined pattern of posterior features may also be seen in lesions that are evolving. One such example is a post lumpectomy seroma, which enhances posteriorly. As the fluid is resorbed and scarring develops, the features of fibrosis become evidence as spiculation of the margins and posterior acoustic shadowing.