Breast calcifications are deposits of calcium that can be seen on a mammogram of the breast. There are two types: macrocalcifications and microcalcifications.
- Macrocalcifications usually are degenerative changes in the breast resulting from old injuries, inflammations, or aging of the breast arteries and are usually not related to cancer. Most often they do not require a biopsy. Macrocalcifications occur in about half the women in the U.S. who are over 50, and in about 10 percent of women under the age of 50.
- Microcalcifications are specks of calcium that may be found in an area of rapidly dividing cells. The residue left by rapidly dividing cells can appear as microcalcifications. When many are seen in a cluster, they may indicate a small cancer. About half the cancers detected appear as these clusters.
Informational brochures about mammography and breast cancer always warn women to look for breast lumps and have them checked, but rarely discuss calcifications or microcalcifications. Most breast calcifications are benign. The term microcalcification is often used for calcifications found with malignancy, which are usually smaller, more numerous, clustered, and variously shaped (rods, branches, teardrops). Calcifications associated with benign conditions are usually larger, fewer in number, widely dispersed, and round. In the middle are hard-to-tell calcifications which are often labeled indeterminate. Magnification views (enlarged mammograms of a particular part of the breast) are sometimes recommended to get a better picture of the quantity, shape, closeness, and arrangement of microcalcifications. If magnification views reveal additional smaller microcalcifications clustered with those visible on the regular mammogram, the likelihood of cancer increases. When calcifications are thought to be associated with benign conditions, a routine mammogram is called for in one or two (or more) years, depending on a woman's age and risk factors. When suspicious microcalcifications appear on a mammogram, but no lump is felt, a needle localization biopsy is recommended, so that breast tissue can be removed and examined under a microscope by a pathologist. Some radiologists take an aggressive approach when dealing with indeterminate calcifications, recommending a needle-localization biopsy to see whether malignancy is present. Others take a wait-and-see approach, recommending that women return in six months for a follow-up mammogram to see if calcifications have changed - a sign that a cancer could be growing. Physicians who recommend "waiting and watching" point to survival statistics, which suggest that a six-month delay in diagnosis and treatment does not affect a woman's chances for a 5-year disease-free outcome. They claim that waiting is not dangerous because six months is a short time in the life of a slow-growing cancer. They also assert that chances for long-term survival with a fast-growing cancer are low, and that early detection does not seem to matter, especially for premenopausal women. Whatever reasons a physician has for recommending a six-month wait, generalities do not address individual cases. Each woman must still decide whether to biopsy indeterminate calcifications. Calcifications revealed on mammograms are thought to be associated with an increased risk of subsequent breast cancer. Women with calcifications in both breasts are at higher risk than women with calcifications in one breast. Women with any calcifications are at higher risk than women with none.