What it is
Men have a small amount of breast tissue behind the nipple, and cancer can start there. It's rare, so men often don't expect it — which is why knowing the signs matters.[1][2]
Male breast cancer is usually treated like breast cancer in women. Because men have less breast tissue, removal of the whole breast (mastectomy) is more common than lumpectomy.[1]
Male breast cancers are almost always hormone-receptor positive. Work-up includes clinical breast exam, mammography and ultrasound, core biopsy, hormone-receptor and HER2 testing, staging imaging where indicated, and genetic testing.[1]
See the chest wall: male breast tissue lies over the pectoralis major muscle.
See it in 3DBreast tissue itself is not modelled as a separate part; the chest wall muscle beneath it and the skin's mammary region are shown.
How common it is
Causes and risk factors
Things you can't change
- Older age.[1]
- Female relatives with breast cancer, or inherited BRCA1/BRCA2 changes.[1]
- Past radiation to the chest.[1]
- Klinefelter syndrome, and testicle problems such as an undescended testicle.[1]
Things you can change
- Obesity and liver cirrhosis, which raise oestrogen levels.[1]
Symptoms worth reporting to a doctor
- A lump or thickening in or near the breast, often under the nipple
- Nipple changes, including turning inward
- Clear or bloody fluid from the nipple
- An open sore, or scaly, red or swollen skin on the breast
- Dimpled skin like orange peel
- Swollen lymph nodes under the arm or near the collarbone
Many breast changes in men have less serious causes, but any unusual change should be checked.[1]
Screening: who, when and how
Screening mammograms are not usually recommended for men. Men at higher risk may be advised to have regular clinical breast exams and to watch for changes.[1]
How it's diagnosed
Stages in general terms
In general terms:[3]
- Localised: still where it started.
- Regional: spread to nearby tissue or lymph nodes.
- Distant: spread to other parts of the body.
An illustration, not a stage. Human Atlas never assigns a stage. Only your own tests and your care team can do that.
Types of treatment
- Surgery. Usually mastectomy, often with lymph node checks.[1]
- Other treatments. As in women, depending on stage and tests: hormone therapy, chemotherapy, radiation or targeted therapy.[1]
Which option fits depends on the details of each person’s situation. Your care team decides with you.
What you can do
Questions to ask your doctor
- Is this lump likely to be gynaecomastia or something else?
- Should I have genetic testing — and should my family?
- Which treatments will I need after surgery?
Myth vs. fact
Guided lesson
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Testicular cancer
A cancer of younger men — the average age at diagnosis is about 33. It's uncommon and usually very treatable. Know what's normal for you.
Understanding cancer: the basics
What cancer is, how screening differs from diagnosis, what 'stage' means, and the main types of treatment — in plain English.
Sources
- National Cancer Institute. Male Breast Cancer Treatment (PDQ®) – Patient Version. Checked 23 October 2026.
- American Cancer Society. Key Statistics for Breast Cancer in Men (2026 estimates). Checked 23 October 2026.
- National Cancer Institute. Cancer Staging. Checked 23 October 2026.
The owner of this website is not a doctor. Human Atlas provides educational anatomy information and does not diagnose, stage, or treat disease. Talk to a qualified clinician about anything concerning your own health.