As breast cells grow and divide, calcium deposits can build up in breast tissue. Called calcifications, these deposits can appear as bright white specks in mammograms. Calcifications don’t develop into breast cancer, and they’re usually associated with benign (harmless) processes. But sometimes they show up in patterns that might indicate breast cancer.

You can’t feel calcifications — they’re too small — and they don’t cause pain. Calcifications are fairly common, especially after age 50. Based on the calcification patterns that appear on a scan, your doctor may order more tests to make sure you’re cancer free.

Types of Breast Calcifications

If your radiologist sees calcifications on your mammogram, they’ll carefully assess the size, shape, and pattern. There are two main types of calcifications, macrocalcifications and microcalcifications, and it’s possible have to have one or both. Whichever type a person has, if calcium deposits are consistently the same size and shape, they’re less likely to be a sign of cancer.

Macrocalcifications

Calcium deposits larger than 0.5 millimeters are called macrocalcifications, which look like lines or dots on a scan. They become increasingly common after menopause, and they’re nearly always signs of a harmless process.

Microcalcifications

Calcium deposits smaller than 0.5 millimeters are known as microcalcifications. They’re also usually nothing to worry about, but doctors examine details of their size, shape, and pattern closely to determine the risk of breast cancer.

Patterns of Calcifications

The patterns formed by calcium deposits are also vital to assessing risk.

Patterns indicating harmless conditions include:

• Spheres with transparent centers — Dead fat cells or a breast cyst that’s hardened over time
• Larger white spots with a coarse shape, resembling popcorn — Benign tumors called fibroadenomas
• Long, smooth lines — Ducts that have become larger and filled with fluid

The pattern that causes concern among radiologists and oncologists involves calcifications that vary in shape and size and cluster in a certain part of the breast. Known as pleomorphic calcifications, this pattern can sometimes indicate ductal carcinoma in situ (DCIS).

Biopsy and Further Testing

If the radiologist judges that the deposits seem benign, no further testing is needed. If the deposits could be associated with an early sign of cancer, the radiologist may recommend more tests, such as an ultrasound or a breast biopsy, or another mammography in six months to see if the pattern has changed. Calcifications grow more rapidly with cancer cells, so a follow-up can provide more detail about risk.

Stay Calm

Being referred for further testing doesn’t need to be a cause for panic. Keep in mind that most biopsies ordered based on calcifications are negative for cancer. Even if you’ve had breast cancer before or have a family risk for breast cancer, calcium deposits are often signs of benign changes in your breast.

If you’ve been treated for breast cancer in the past, you may have anxiety around breast imaging because you’re worried about a relapse (disease recurrence). Breast cancer treatments such as surgery and radiation therapy make calcifications more likely to develop, so it’s not unexpected to see them on a scan.

Limits of Calcifications in Screening

It’s also important to recognize that while calcification patterns can be useful in screening, they have their limitations. Researchers have reported false-positive biopsy rates of between 30 percent and 87 percent for calcifications. This means that the radiologists’ impressions of the calcifications patterns weren’t accurate, indicating cancer when no cancer was present. As a result, people may worry and undergo additional testing needlessly.

If you have questions about screening or testing for breast cancer, talk with your doctor. They can help you assess the benefits and risks of each type of test and understand what your individual results mean.

Can Calcifications Be Prevented or Reduced?

There’s nothing you can do to prevent breast calcifications, and they’re not connected to calcium in supplements or the food you eat.

Finding fewer calcifications in a follow-up mammogram is rare and, in fact, may indicate cancer. While a shrinking tumor is often a sign that your outlook is improving, reductions in calcifications are very different. Reducing calcifications, even if it were possible, would not lower your risk of breast cancer.

Talk With Others Who Understand

MyBCTeam is the social network for people with breast cancer and their loved ones. On MyBCTeam, more than 65,000 members come together to ask questions, give advice, and share their stories with others who understand life with breast cancer.

Have you had a mammogram that showed calcifications? Were you referred for further testing? Share your experiences in the comments below, or start a conversation by posting on your Activities page.