Calcifications are tiny mineral deposits in the breast tissue. When observed on a mammogram, calcifications may appear singly or in clusters.
There are two types of calcifications: macrocalcifications and microcalcifications. The presence of one or the other type of these calcifications helps radiologists determine how to interpret a mammogram.
Clusters of calcifications may indicate the presence of cancer, particularly clusters of microcalcifications, which often are associated with ductal carcinoma in situ (DCIS). DCIS is the most common form of non-invasive, early stage breast cancer. Treated early, DCIS is extremely curable. The presence of clusters of microcalcifications often results in a Category 4 or Category 5 evaluation. Nearly half of all cancers found by mammogram are identified by the presence of microcalcification clusters.