How Breast Cancer Is Diagnosed

Expect tests and biopsies

In This Article

A breast cancer diagnosis often starts with a mammogram. If something suspicious shows up, your doctor will likely start you down a multi-step process for diagnosing or ruling out breast cancer. That involves self-checks, clinical evaluation, imaging tests, and biopsy procedures.

If you develop symptoms of breast cancer, you should seek medical attention. However, breast cancer can be diagnosed long before symptoms occur. Breast self-checks, your doctor's clinical examinations, and yearly mammograms are diagnostic screening tools that can detect early-stage breast cancer.

Earlier-stage breast cancer is typically more easily treated and has a better outcome than later-stage breast cancer.

Self-Checks/At-Home Testing

Breast cancer can produce changes in the appearance or texture of your breast. Women (and men) need to pay attention to any variations, which can include discoloration, a visible lump, nipple discharge, or bleeding. Painful breasts can also be a sign of breast cancer, but it's a rare one.

Women should start doing monthly breast self-checks during the teenage years and continue throughout life, and men who are at risk of breast cancer should also do monthly self-checks.

Regular breast self-checks are an important part of a breast cancer diagnosis. You may be able to feel lumps and growths with your fingers even if they don't produce visible changes in your breasts. Experts recommend monthly breast self-examination, which should be mid-cycle (two weeks after your period) if you are premenopausal.

Labs and Tests

A number of tests can help diagnose breast cancer. A clinical breast exam is a standard part of your yearly physical, and some women will also have genetic testing for breast cancer, although this is not standard.

Physical Exam

During your annual physical, your physician will typically conduct a clinical breast exam to identify lumps or variations in your breasts.

Your doctor will ask you about any changes you may have noticed, such as marks on your skin or an inverted nipple. If these are congenital (meaning you've had them since birth), then they aren't necessarily concerning even if they're unusual. Your doctor may note congenital breast issues in your chart so that your medical team will be aware of them and follow up on changes.

If you have one or more lumps, your doctor will recommend an imaging test, and possibly a biopsy as well. If you have dense or large breasts, it may be difficult for your doctor to feel small lumps during an examination.

Genetic Testing

Mutations are defects in genes, and they can lead to cancer. Numerous mutations are associated with breast cancer.

No blood tests can diagnose breast cancer, but genetic testing (which typically uses a blood sample or saliva) can identify a predisposition to the condition.

This testing may be recommended for women who have already had cancer at a young age (before menopause), who have a strong family history of the condition, or who have family members who carry breast cancer genes. In some instances, men may be tested for breast cancer genes as well.

BRCA genes, including BRCA1 and BRCA2, are the most common genes associated with breast cancer. Additionally, at least 70 non-BRCA gene mutations have also been linked to the condition. Your test will be tailored to your medical history and family history to detect the genes you are most likely to have.

You can also order at-home genetic tests for breast cancer for yourself without a doctor's recommendation, but these can only detect a few of the genes that are associated with breast cancer. Doctors have access to more comprehensive tests.

Genetic testing can tell you if you have a predisposition to breast cancer, but it cannot tell you whether you do or don't have the disease. You can develop breast cancer even if you don't have any breast cancer genes.


A mammogram is an X-ray image of the breast. It's a key screening tool that can detect breast cancer up to two years before it can be felt by physical examination. Screening mammograms are recommended yearly for women over the age of 40, and sometimes for younger women or men who have a high risk of breast cancer.

Mammograms can visualize benign (non-cancerous) breast conditions and breast cancer, but they can't always verify the difference.

A few other imaging tests are also used in breast cancer diagnosis.

Diagnostic Mammogram

While a screening mammogram looks at the whole breast, a diagnostic mammogram generally examines one section in greater detail, usually by getting more images of a small area to visualize it better. You might have a diagnostic mammogram if your doctor is concerned about something on your screening mammogram.


Breast ultrasound creates images of the breast using sound waves. Sometimes used as a follow-up test after a mammogram with an abnormal finding, a breast ultrasound can help differentiate between a liquid-filled cyst and a solid mass, such as a tumor.

Breast Magnetic Resonance Imaging (MRI)

Breast MRI uses magnetic fields to create an image of the breast. It may be recommended to aid diagnosis in some instances but is not used in all situations because it's not as effective as a mammogram for many breast conditions.

While these imaging techniques can help with diagnosing breast cancer, a biopsy is the only test that can make a definite diagnosis.

Breast Biopsies

During a breast biopsy, a small tissue sample is removed from an area of concern in the breast. A pathologist then examines the tissue under a microscope. Some molecular characteristics are tested, as well.

Several biopsy types and methods are used to diagnose breast cancer.

  • Fine needle aspiration (FNA): A small amount of tissue is taken from the suspicious area using a thin needle attached to a syringe. If the sample turns out to be a cyst, the fluid in the cyst can be drained. If the sample contains cancerous cells, you may need to have a larger biopsy, and you will most likely need to have your breast cancer surgically removed.
  • Core needle biopsy: A large hollow needle withdraws tissue from the suspicious area in the breast, providing a larger sample than a fine needle aspiration.
  • Stereotactic core needle biopsy: X-ray equipment and a computer analyze pictures of the breast. The computer helps direct the needle to the exact location that requires biopsy.
  • (MRI)-guided biopsies: These are used for women with a suspicious area that can only be found by MRI.
  • Vacuum-assisted core biopsy: A small incision is made and a tissue sample removed with the assistance of suctioning pressure.
  • Excisional biopsy: The entire area of abnormality is removed. This is particularly common if the mass is small.

    These procedures generally involve numbing the skin around the area, and you may need a few stitches after your procedure. You might experience mild pain for a few days after a breast biopsy, but most women do not experience any pain or adverse effects afterward.

    If your breast cancer might have metastasized (spread beyond your breast), your surgeon may also take a sample of tissue from the lymph nodes underneath your arm. This sample will be examined to see if it contains breast cancer cells, which is evidence of metastatic breast cancer.

    Breast Cancer Staging and Grading

    A pathology evaluation will detect the absence or presence of breast cancer in your biopsy sample.

    The pathology report will describe the type of breast cancer and its characteristics, such as:

    • Whether it's invasive or noninvasive
    • Size
    • Growth rate
    • Hormone and genetic status
    • Other factors that will influence treatment planning

    When test results are completed and reviewed, your doctor will determine the grade and stage of your cancer. Staging is the process of determining the spread of cancer at the time it is found, and this relies on imaging tests as well as a pathology report. Cancer grade is a way of describing how aggressive the cancer is and how likely it is to grow and spread.

    Breast Cancer Doctor Discussion Guide

    Get our printable guide for your next doctor's appointment to help you ask the right questions.

    Doctor Discussion Guide Woman

    While breast cancer cells in the sample provide a definitive diagnosis of breast cancer, you may have the disease even if no cells were found in that particular sample.

    Differential Diagnosis

    Not all lumps or suspicious mammogram images are a sign of cancer. It could be due to a lot of other things, including benign (harmless) breast lesions such as cysts, fibroadenomas, and fat necrosis. A pre-cancerous lesion, such as a radial scar or carcinoma in situ, is also possible. Pre-cancerous lesions can evolve into breast cancer, but they have a very high cure rate if treated promptly.

    And, while it is not common, a breast mass or lump can be the result of metastasis (spread), from another cancer in the body.

    A Word From Verywell

    While it may be difficult, try not to jump to conclusions about what's going on after a suspicious mammogram or if you or your doctor have found a lump. It may not be cancer at all, and if it is, you have a lot of treatment options available to you.

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