Abnormal Mammogram: What Happens Next?

Fewer than 1 in 10 women who are called back for more testing after a screening mammogram are found to have breast cancer. More than nine out of ten callbacks end without a cancer diagnosis.

A callback means the radiologist saw an area on the images that they cannot fully explain from the screening pictures alone. Screening mammograms use a small number of standard views. When something overlaps, looks slightly different from last time, or simply is not clear, the answer is more pictures — not a diagnosis.

Your results letter will explain what follow-up exams you may need. Screening results usually arrive within about two weeks, either by mail or in your electronic medical record.

Mammogram reports use a scoring system called BI-RADS. The number tells you exactly what the radiologist concluded and what should happen next.

Category	What it means	What follows
0	Need additional imaging evaluation	More imaging before a final category can be given
1	Negative	Continue regular screening mammograms
2	Benign (not cancer)	Continue regular screening mammograms
3	Probably benign	A follow-up mammogram in 6 months
4	Suspicious abnormality	May require biopsy
5	Highly suggestive of malignancy	Requires biopsy
6	Known biopsy-proven cancer	Biopsy already confirmed cancer before treatment

Most callbacks after a screening exam are category 0. That is a request for more information, not a verdict.

Your doctor will review your medical history and do a clinical breast exam. Then, depending on what was seen, one or more of these:

Diagnostic mammogram. More detailed x-ray pictures of the breast taken from different angles, so the abnormal area can be looked at closely. Because it needs images from more angles than a screening mammogram, the radiation dose is higher.

Breast ultrasound. High-energy sound waves make pictures of the inside of the breast. Ultrasound is especially good at answering one question quickly: is this lump solid, or is it a fluid-filled cyst?

Breast MRI. A powerful magnet, radio waves, and a computer make detailed pictures, usually after contrast dye is injected. MRI is used as a supplement to mammography, mainly for people at high risk.

Cysts are closed, sac-like pockets of tissue filled with fluid. They are most common before menopause and do not raise your risk of breast cancer.

Fibroadenomas are hard, round lumps that move easily under the skin. They are the most common benign breast tumors in women under 30, and simple fibroadenomas do not raise breast cancer risk.

Calcifications are calcium deposits visible on a mammogram but too small to feel. Large ones (macrocalcifications) are usually benign. Smaller ones (microcalcifications) are usually harmless too, but when they appear in tight groups they can be a sign of DCIS or cancer, which is why the radiologist wants a closer look at them.

A biopsy is the only sure way to diagnose breast cancer. Being sent for one does not mean the answer is already known.

• Fine-needle aspiration uses a thin needle to draw out fluid or cells.
• Core needle biopsy uses a wider needle to remove tissue samples about the size of a grain of rice.
• Vacuum-assisted biopsy removes a small tissue sample through a probe connected to a vacuum device, using a much smaller cut than surgery.
• Image-guided biopsy uses mammography (stereotactic), ultrasound, or MRI to steer the needle to the exact spot.
• Surgical biopsy either takes a sample of the area (incisional) or removes the whole lump or suspicious area (excisional).

Most biopsies are outpatient procedures. Non-surgical biopsies usually do not need anesthesia. Surgical biopsies use local or general anesthesia and take longer to recover from.

The pathologist then reports what the tissue shows — including where any abnormal cells sit (in the ducts or the lobes), the grade, and whether they have invaded surrounding tissue.

BI-RADS category 3 means the radiologist thinks the finding is very likely not cancer but wants to be certain it is not changing. The plan is a follow-up mammogram in 6 months. Put that date in your calendar before you leave the building.

• What is my BI-RADS category?
• Do I need follow-up testing, and which test?
• Why is this test needed, and what will it tell you?
• What do these findings mean?
• When will I know the biopsy results?
• When should I get my next mammogram?

Waiting for cancer test results is stressful. Ask directly when the results will be ready and who will contact you.

• National Cancer Institute — Understanding Breast Changes: A Health Guide: https://www.cancer.gov/types/breast/breast-changes/understanding-breast-changes.pdf
• National Cancer Institute — How Is Breast Cancer Diagnosed?: https://www.cancer.gov/types/breast/diagnosis
• National Cancer Institute — Mammograms: https://www.cancer.gov/types/breast/mammograms-fact-sheet