Gynaecomastia and breast cancer in men

Summary points

• Most breast enlargement in males is due to the benign enlargement of breast tissue (gynaecomastia)

• Physiological gynaecomastia occurs in neonates, at puberty, and with obesity and ageing

• Gynaecomastia is due to an increased oestrogen to testosterone ratio; possible causes are many

• Treatments for painful or embarrassing gynaecomastia include an anti-oestrogen, such as tamoxifen, or surgery (liposuction or mammoplasty)

• One per cent of breast cancers occur in men, with higher rates in men with a family history of breast cancer or previous chest radiation

• Irregular, eccentric, hard or fixed breast tissue, ulceration, nipple abnormalities, or associated adenopathy suggest breast cancer

• Men typically have more advanced breast cancer at diagnosis than women; management is similar

Sources and selection criteria

We searched Medline for English language papers with the key words “gynaecomastia”, “gynecomastia”, and “male breast cancer”; the Cochrane database for clinical trials; our personal archives of references; and websites with those terms. We also referred to our institutional experience with gynaecomastia and male breast cancer.