According to the American Cancer Society, calcifications or microcalcifications seen on a mammogram are small mineral deposits that show up as white spots on the mammogram film. Calcifications can be benign, but they may be a sign of breast cancer.

Calcifications can be sorted into two groups: macrocalcifications and microcalcifications.

Macrocalcifications are large deposits of the mineral calcium, and are most likely caused by aging of the breast arteries, old injuries, or inflammation. These deposits are related to noncancerous conditions and do not require a biopsy.

Microcalcifications are small pieces of calcium in the breast tissue. They may appear alone or in clusters. Microcalcifications are more worrisome, but do not always signal the presence of cancer. The shape and pattern of microcalcifications will help determine whether cancer is present. In most cases, microcalcifications do not require a biopsy.

Sometimes additional tests, such as repeat mammograms, are used to monitor calcifications. In cases where the microcalcifications are more suggestive of cancer, the health care provider will recommend a breast biopsy. A biopsy is more likely if the calcifications are tightly clustered or have characteristics that concern the radiologist.