How Is Breast Cancer Diagnosed?

Learn how breast cancer is diagnosed, including mammograms, breast biopsies, MRI-guided testing, biopsy results, and next steps after screening.

Older woman sitting on couch with two men in the background of the image

Updated September 18, 2026

By Lori Timmerman, DO, Breast Surgeon, Virtua Breast Care

Breast cancer is often detected before symptoms appear through routine mammograms. However, some women notice a breast lump, changes in their breasts, or other symptoms that require further evaluation. If a screening or physical exam detects a suspicious area, additional testing can help determine whether cancer is present.

The diagnostic process may include imaging tests, biopsies, and laboratory analysis of breast tissue. Understanding what to expect can help you feel more informed and confident throughout the process.

What happens after an abnormal mammogram?

An abnormal mammogram doesn't automatically mean you have breast cancer. In fact, many abnormal findings are benign, such as cysts, fibrocystic breast changes, or noncancerous growths.

If an area of concern is identified, your health care provider may recommend:

Additional mammogram images
Breast ultrasound
Breast MRI
A breast biopsy

These tests provide more information and help determine whether the abnormality is cancerous or benign.

Common symptoms that may lead to breast cancer testing

While many breast cancers are found through routine screening, some women seek medical evaluation after noticing symptoms, including:

A new breast lump or thickening
Changes in breast size or shape
Persistent breast pain
Nipple discharge
Nipple inversion
Dimpling or puckering of the skin
Redness or swelling of the breast

If you notice any of these symptoms, contact your health care provider immediately.

Tests used to diagnose breast cancer

Breast cancer diagnosis typically involves a combination of imaging studies and tissue sampling.

Breast imaging

Imaging tests help doctors identify suspicious areas and determine whether a biopsy is needed.

Common imaging tests include:

Diagnostic mammography: Provides additional images of the breast after an abnormal screening result.
Breast ultrasound: Uses sound waves to evaluate lumps and abnormalities.
Breast MRI: Uses magnetic fields and contrast dye to create detailed breast images, particularly in women with dense breast tissue or higher cancer risk.

While imaging can identify areas of concern, a biopsy is the only way to confirm whether cancer is present.

Breast biopsies

A biopsy removes breast cells or tissue so a pathologist can examine them under a microscope. Needle and surgical biopsies are the primary approaches.

Fine needle aspiration biopsy: Fine needle aspiration uses a thin needle to collect fluid or cells from a suspicious area. It's the least invasive biopsy option and may be useful for evaluating cysts or certain breast abnormalities. However, because the sample is small, additional testing may sometimes be necessary.
Core needle biopsy: A core needle biopsy uses a hollow needle to remove small cylinders of breast tissue. In some cases, a vacuum-assisted device may be used to obtain larger tissue samples. This is one of the most common biopsy techniques because it provides sufficient tissue for an accurate diagnosis while avoiding surgery in many cases.
Surgical biopsy: A surgical biopsy removes part or all of the suspicious area for examination. This procedure is typically performed in an outpatient setting using local anesthesia and sedation. A surgical biopsy may be recommended when a needle biopsy isn't possible or when additional tissue is needed for diagnosis.

Image-guided breast biopsies

When a lump or abnormality can't be easily felt, imaging technology can help guide the biopsy.

Stereotactic biopsy: A stereotactic biopsy uses mammography and computer-assisted imaging to precisely locate an abnormal area in the breast. This technique helps physicians accurately guide a core needle to the target tissue.
Ultrasound-guided biopsy: Ultrasound uses sound waves to visualize breast tissue in real time. It can guide a needle to the area of concern or assist with certain surgical procedures. Ultrasound-guided biopsies are often comfortable and efficient because they provide continuous visualization throughout the procedure.
MRI-guided biopsy: MRI-guided biopsy is used when an abnormality is visible on MRI but not on mammography or ultrasound. During the procedure, detailed MRI images guide the biopsy needle to the precise location.
Wire localization: Wire localization uses imaging guidance to place a thin wire or needle into a breast abnormality that can't be felt. The wire guides the surgeon to accurately remove the targeted tissue.

Understanding your breast biopsy results

After your biopsy, a pathologist examines the tissue sample to determine whether cancer cells are present.

Results may show:

Benign (noncancerous): The abnormality is not cancer and may require no treatment or routine follow-up monitoring.
Atypical cells: The tissue contains abnormal cells that aren't cancer but may increase future breast cancer risk. Additional evaluation may be recommended.
Ductal carcinoma in situ (DCIS): DCIS is a noninvasive form of breast cancer in which abnormal cells remain confined to the milk ducts.
Invasive breast cancer: Cancer cells have spread beyond the ducts or lobules into surrounding breast tissue. Additional testing helps determine the specific type and stage.

How long does it take to receive results?

The timeline varies depending on the testing performed. Imaging studies are often reviewed within a few days, while biopsy results are commonly available within several business days. Your care team will discuss your results and next steps as soon as they become available.

What happens if breast cancer is diagnosed?

If cancer is found, additional tests may be performed to better understand the disease and guide treatment decisions.

These may include:

Tumor receptor testing (estrogen, progesterone, and HER2)
Additional imaging studies
Genetic testing when appropriate
Cancer staging evaluations

Your care team may include breast surgeons, medical oncologists, radiation oncologists, radiologists, pathologists, nurse navigators, and other specialists who work together to create a personalized treatment plan.

Virtua is here with comprehensive breast care

Learn more about Virtua's breast health program, which offers the latest imaging technology, including 3-D mammography, breast ultrasound, and MRI, and includes a high-risk breast cancer evaluation and surveillance program.