Calcium deposits in the breast tissue are calcifications, which despite popular belief are not related to the calcium that is ingested via supplements or diet. They can be composed of calcium phosphate or calcium oxalate and can arise from a variety of etiologies.
Calcifications appear as white dots or flecks on a mammogram (breast X-ray) that cannot be felt during a routine breast examination. These deposits of calcium are very common and be seen in up to 8 out of every 10 mammograms.
Breast calcifications are especially prevalent on mammograms after menopause and although most are usually benign (non-cancerous), certain patterns seen on a radiographic such as irregular shapes or tight clusters may be early indicators of breast cancer or precancerous changes to the breast tissue.
The presence of a benign breast calcification does not increase the risk of developing breast cancer. There are two types of breast calcifications: macrocalcifications and microcalcifications. Microcalcifications are grouped according to their underlying etiology, morphology, distribution, or location.
Macrocalcifications tend to be more prevalent in women after the fifth decade of life and they are coarser, larger calcium deposits. They are mostly associated with breast changes caused by arterial vessels in breast aging, injuries to the breast tissue from events such as trauma or surgery, inflammation of the breast tissues and benign growths such as fibroadenoma and cysts.
Macrocalcifications are almost always not associated with any malignancy and usually no further testing like biopsies or follow-ups are required.
Tiny calcium deposits in the breast tissue represent microcalcifications. These calcifications may suggest areas of increased activity in mammary cells whose uptake of calcium increases in proportional to their increased activity. Microcalcifications may be found solitary or in clusters and in some cases might be an indication of a cancer like ductal carcinoma in situ (DCIS).
Suspicious microcalcifications are biopsied and a repeat mammography is conducted in six months to rule out a neoplastic process. In cases where follow-up has been advised, it is imperative to note that some microcalcifications go for many years unchanged. Furthermore, some calcifications have been even seen to resolve.
Microcalcifications based on location can be classified with terms such as lobular (well defined and punctate), intraductal (DCIS), vascular (visible tram line if both walls of the vessel are calcified), and dermal (calcifications with lucent center) among others.
If the distribution of microcalcifications is taken into account then they may be diffuse, regional, clustered, linear or segmental, which are found throughout the breast, in particular regions, in small volumes, in a line or in segments, respectively.
The morphology of microcalcifications can be pleomorphic (varying shape, size, and density), rounded, punctuate, or amorphous. Pleomorphic calcifications are potentially alarming as they can be cancerous in nature. If grouped according to underlying etiology, then microcalcifications can be as a result of fat necrosis, malignancies, fibrocystic changes, fibroadenomas, metabolic abnormalities (e.g., tumoral calcifications within the breast), and from parasitic infections of the breast.
Reviewed by Susha Cheriyedath, MSc