Breast Calcifications on Your Mammogram: What to Know

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Breast calcifications are calcium deposits that appear as white dots on a mammogram. They can vary in type (i.e., size), pattern, and arrangement, and the significance of each of these can vary considerably.

While many people associate calcifications with breast cancer, there are a number of other potential causes, ranging from benign breast conditions such as fibroadenomas to conditions unrelated to the breast.

It helps to know the characteristics of calcifications and how they may determine the meaning of any changes on your mammogram.

Breast calcifications are a very common finding on mammograms. In fact, half of all women over the age of 50 will have some type of calcification show up. The vast majority of these will be non-cancerous.

Non-Cancerous Causes for Breast Calcifications
Verywell / Cindy Chung

Types of Breast Calcifications

There are two types of breast calcifications, and they often mean very different things. Instead of using the following terms, your healthcare provider may simply call them large or small.


Macrocalcifications are large bits of calcium deposits found on a mammogram. They may be due to natural changes in a woman's breast, like hardening of her breast arteries. Macrocalcifications may also represent areas of inflammation from an old injury or breast trauma.

There is usually no need to worry about these larger breast calcifications. They are not usually linked to breast cancer and are more common in women 50 and older.


Microcalcifications are tiny bits of calcium deposits that may be an early sign of breast cancer, although they aren't always.

Pattern and Shape of Breast Calcifications 

The pattern and shape of microcalcifications are often different depending on whether the finding is benign (noncancerous) or malignant (cancerous). For example, calcifications described as eggshell, rim-like, popcorn-like, railroad tracks, coarse, or arranged in a loose cluster typically are benign. A high volume of calcifications that don't follow ducts is also a sign that they're not cancerous.

Calcifications that are irregular in size or shape, such as spiculated (spiky) calcifications, may be suspicious. Calcifications arranged in a tight cluster also raise concerns about cancer.

Likely Not Cancerous
  • Rim-like, popcorn-like, coarse

  • Railroad track pattern

  • Don't follow ducts

  • Loose cluster arrangement

Possibly Cancerous
  • Irregular size or shape

  • Spiky

  • Tight cluster arrangement

Benign (Noncancerous) Causes of Calcifications

Many different things can cause breast calcifications, both those that are benign and those that suggest malignancy.

Some of the benign causes of breast calcifications include:

  • Scar tissue related to old breast injuries (dystrophic changes), leftover from prior breast cancer surgery (fat necrosis), injuries or trauma to the breast, or simply due to the natural wear and tear of the breasts
  • Mastitis or inflammation caused by a breast infection
  • Calcium collected inside a dilated milk duct
  • Calcium mixed with fluid in a benign breast cyst
  • Radiation treatment for breast cancer
  • Calcification in the arteries within your breast
  • Calcifications in a fibroadenoma (benign growth)

Powders, ointments, or deodorants deposit calcium on the skin that may be mistaken for breast calcifications, which can cause concern about abnormal breast changes. That's why you're advised not to put on deodorant before a mammogram.

How Breast Calcifications Are Diagnosed

If your mammogram shows microcalcifications that may suggest breast cancer, a biopsy is recommended. A biopsy means that a small area of the suspicious breast tissue is removed and examined under a microscope for cancer cells.

The most common procedure after calcifications are found is a stereotactic breast core biopsy. In this procedure, the healthcare provider uses imaging to guide the process and make sure tissue from the suspicious area is sampled.

The odds of a breast calcification being cancerous are not high. In a 2019 study, 27.9% of those who had more than one calcification biopsied were found to have cancer. However, it is important to note that only suspicious calcifications need to be biopsied. Macrocalcifications, for example, don't usually point to cancer.

A biopsy is not always needed if there are microcalcifications; sometimes close follow-up is all that's warranted. No matter the course you and your healthcare provider decide to take, it’s extremely important to get the recommended follow-up exams and tests for safeguarding your health.

Treatment of Breast Calcifications

Benign breast calcifications do not need treatment. If your healthcare provider determines that they are not cancerous, you do not need to have your breast calcifications removed.

Calcifications in Breast Cancer

While the presence of calcifications on a mammogram can sometimes alert healthcare providers to breast cancers that would otherwise go undetected, experts are learning that breast calcifications also may provide information about the prognosis of breast cancer.

According to a 2018 study, breast cancers that have microcalcifications are more likely to be HER2-positive, tend to have a higher tumor grade, are more likely to have spread to lymph nodes, and have a greater risk of recurrence. This information may be helpful for women with early-stage breast cancers who are weighing the benefits of treatments such as chemotherapy after surgery.

Arterial Calcifications and Heart Disease

Calcifications believed to be in the arteries of the breast have traditionally been thought of as incidental findings not associated with breast cancer risk, so they didn't get much attention. However, that's changing.

Research from 2014 suggests that the presence of breast arterial calcifications is associated with underlying coronary artery disease in women over 40 who don't have any symptoms of heart disease. Their presence was even more likely to predict the presence of arteriosclerosis than risk factors such as high blood pressure, a family history of heart disease, and more.

Unfortunately, symptoms of coronary artery disease or a heart attack in women are often different from what is considered "typical," and symptoms such as profound fatigue, nausea, or even jaw pain may be the only ones heralding these concerns. Mammograms may, by finding arterial calcifications, help in detecting coronary artery disease before problems occur.

Since much of the research looking at the meaning of breast arterial calcifications is relatively new, it's important to be your own advocate and ask questions if you should see a note about these on your report.

A Word From Verywell

Healthcare providers do not always mention the word calcifications when talking to women about their mammograms. They may instead mention a "small abnormality." Ideally, you should ask for your report so that you can review it. Ask specifically what was found if you have an abnormal result, and be sure to ask about the description and pattern of any calcifications.

9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Lynne Eldridge, MD
 Lynne Eldrige, MD, is a lung cancer physician, patient advocate, and award-winning author of "Avoiding Cancer One Day at a Time."