What Does Breast Cancer Look Like on a Mammogram?

Ask a Doctor

I got my first mammogram yesterday, and luckily, it showed no lumps or masses that were concerning for the doctor. My question is, how did she know there was nothing wrong? The mammogram looked like just a gray-and-white mess, and I can’t imagine getting useful information from it. How do they know if a lump is worrisome? What does breast cancer look like on a mammogram?

Doctor’s Response

A mammogram is basically an X-ray image of the breast. The breast is compressed between two firm, flat surfaces to spread the tissue out. A mammogram can show breast changes such as calcifications, masses, or other symptoms that might be cancer. Abnormalities such as cancerous tumors usually appear brighter because they are denser.

Calcifications are calcium deposits within the breast tissue and they look like small white spots. A mass (a lump or tumor) may also be noted on a mammogram as an irregularly shaped shadow. A mass can also be non-cancerous, such as a fluid-filled cyst or a solid benign tumor (fibroadenoma).

Mammograms can also assess breast density, which shows the distribution of fibrous and glandular tissues in the breast versus fatty tissue. Dense breasts are common, and they are associated with a higher risk of breast cancer. Women without a history of breast problems usually have a screening mammogram performed. For women with a history of breast problems, a targeted mammogram may be performed to better evaluate a particular area of the breast. Sometimes special mammograms may be requested by your doctor.

  • Diagnostic mammogram: If results of a screening mammogram are unclear, abnormal, or if additional images are desired, the woman is asked to return for a diagnostic mammogram, which consists of additional images than those taken in the screening mammogram.
  • Ductogram: If additional views are needed for specific reasons, such as bloody discharge from the nipple, the doctor may request a ductogram. It consists of mammography performed after a fine plastic tube is placed into the opening of the duct into the nipple and a small amount of dye is administered.
  • Pneumocystography: This mammography is performed after a cyst is emptied with fine-needle aspiration and core biopsy, usually after the cyst has been seen on an ultrasound or if the cyst can be felt.
  • Stereotactic mammography: Based on mammograms taken from two angles, a computerized map shows the precise location of masses or calcifications. This technique allows, after local anesthesia, a metallic wire with a little hook at the end to be inserted into a breast lump. The wire then guides the surgeon during surgery to remove the tumor and the surrounding healthy tissue completely. After removal, a new film of the breast is taken to ensure that all the suspicious tissue has been removed. However, a stereotactic biopsy may be performed in which a small computer-controlled system guides the placement of a needle into the lesion or lump for sampling in a laboratory.
    • Two instruments have been developed to obtain stereotactic breast biopsies: the mammotome and the advanced breast biopsy instrument (ABBI). Both instruments use a rotating knife that cuts the tissue samples from the rest of the breast. Each type of biopsy has distinct advantages and disadvantages, but their accuracy is similar if well performed.
  • Other procedures are in limited use and some are undergoing clinical trials. These mammography procedures are used to improve the diagnostic accuracy of mammograms and are as follows: 3D mammography, MRI mammography, positron emission tomography (PET scan mammography), and diffuse optical tomography (light instead of X-rays produce the mammogram). Each specialized test has advantages and disadvantages; the radiologist who does the test can explain the need for such a new test.
  • Sometimes a woman could be recalled after a few days because the radiologist simply wants to be sure the breast images are the best possible and for a better evaluation of certain areas of the breast. In such cases, special mammographic tests may be performed.
  • If cancer is found, a number of treatment options, including surgery, radiotherapy, hormone treatment, and chemotherapy are available. The treatment option must be based on the individual woman and the type and size of breast cancer present.
  • What diseases or disorders can mammography diagnose?
  • Any suspicious area on a mammogram will be magnified and examined. The radiologist reading the mammogram will consider all views taken. Generally, if the radiologist can see defined margins in a suspicious area, they may indicate a benign or harmless lesion. If they are undefined, the mammogram may indicate a malignant or cancerous lesion. Obviously, the experience of the doctor who evaluates the mammogram is fundamental in order to distinguish the benign lesions from the malignant ones.
  • A mammogram could show white spots called - according to their size - calcifications and microcalcifications. The first are small deposits of calcium salts that occur in the breasts for many reasons. The second are very tiny and can be scattered throughout the breasts or gathered in small clusters and are normally due to aging or noncancerous causes (for example, from aging of the breast arteries, old injuries, or inflammations). Most of them are of no concern.
    • Suspicious microcalcifications must be evaluated further, and the doctor will consider their number, size, and where they are located, among other characteristics. Sometimes calcifications can indicate the presence of early breast cancer, but usually they just indicate the presence of tiny cysts.
    • If some microcalcifications are present on a mammogram, the woman may be asked to return for further assessment and use of special X-rays, which magnify the concerned area of the breast.

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Melissa Conrad Stöppler, MD coauthored this article


American Cancer Society. What Does the Doctor Look for on a Mammogram? 9 October 2017. 31 December 2018 .