Breast calcifications are small calcium deposits within breast tissue that appear as white spots on a mammogram. These deposits are a common finding, are too small to be felt during a physical exam, and in most instances, are benign (non-cancerous). While generally harmless, their appearance can sometimes signal early tissue changes that warrant a closer look.
Identifying Calcifications on a Mammogram
Macrocalcifications
The first major category is macrocalcifications, which are larger deposits. These appear as distinct, coarse white dots or dashes scattered randomly throughout the breast tissue. They are a frequent finding, especially in women over the age of 50, and are almost always considered benign. Because their appearance is so characteristic, macrocalcifications usually do not require any additional testing or follow-up.
Microcalcifications
Microcalcifications consist of tiny, fine specks of calcium, sometimes compared to grains of salt. While most are also benign, certain patterns can raise suspicion and require more detailed evaluation. Radiologists pay close attention when these specks are grouped in a tight cluster, form a linear or branching pattern, or have irregular shapes. These arrangements might indicate an area of increased cellular activity associated with precancerous or cancerous cells.
Common Causes of Benign Calcifications
Benign breast calcifications are often a byproduct of natural processes. A common cause is the aging of breast arteries, where calcium deposits form in the vessel walls. Previous trauma or injury to the breast tissue can also lead to calcification as part of the healing process.
Other non-cancerous conditions associated with calcification development include:
- Fibrocystic changes, a condition that can cause lumpy or rope-like breast tissue
- Benign breast cysts or non-cancerous growths known as fibroadenomas
- Past infections in the breast, such as mastitis
- Inflammation of the milk ducts
Dietary calcium intake does not influence the formation of breast calcifications.
When Calcifications Suggest Malignancy
Specific patterns of microcalcifications can be an early indicator of an underlying issue like Ductal Carcinoma in Situ (DCIS). In DCIS, abnormal cells contained within a milk duct create calcifications as they grow and die off. A suspicious finding on a screening mammogram will prompt a move to a diagnostic mammogram for more detailed images.
A diagnostic mammogram provides detailed images of the area, often using magnification views to enlarge the microcalcifications. This allows the radiologist to better assess their shape, size, and distribution pattern. The radiologist then uses the Breast Imaging Reporting and Data System (BI-RADS) to classify the findings. A BI-RADS category of 4 (suspicious) or 5 (highly suspicious) indicates a biopsy is recommended.
The Role of a Biopsy
A biopsy is the only procedure that can definitively diagnose whether cells associated with suspicious calcifications are benign or malignant. The most common method is a stereotactic core needle biopsy, a minimally invasive procedure guided by mammography.
During the procedure, a mammography machine takes X-rays from two angles to create a 3D map of the breast, allowing the radiologist to pinpoint the calcifications. A hollow needle is then guided to the targeted area to remove several small core samples of tissue. These samples are sent to a pathologist for microscopic analysis, and the resulting pathology report provides the final diagnosis to guide further treatment.