A mammogram is first checked by the technologist and then read by a diagnostic radiologist. The radiologist looks for unusual shadows, masses, distortions, special patterns of tissue density and differences between the two breasts. The shape of a mass can be important too. A growth that is benign, such as a cyst, looks smooth and rounded and has a clearly defined edge. Breast cancer, in contrast, often has an irregular outline with finger-like extensions.
Many mammograms show nontransparent white specks.
These are calcium deposits known as calcifications. Macrocalcifications are coarse calcium deposits and are often seen in both breasts. They are most likely due to aging, old injuries or inflammations. Microcalcifications are tiny flecks of calcium found in an area of rapidly dividing cells. Clusters of numerous micro- calcifications in one area can be a sign of ductal carcinoma.