Breast Disease in Men

Gynaecomastia is a breast manifestation of a systemic problem. Secondary care referral and investigation is not necessary in the vast majority of cases.

Breast lumps in men (rather than generalised breast swelling), or other suspicious features such as nipple inversion, nipple discharge or distortion should be referred to the Breast Unit as USC – please see guidance on RefHelp Breast Lump page and/or RefHelp Nipple Symptoms page.

The vast majority of referrals referred to EBU as men with breast lumps are found to have gynaecomastia. It is therefore recommended that in most cases where referral is being arranged, gynaecomastia bloods are arranged either prior to referral, or at point of referral.

However, if the clinical picture is clearly suggestive of a likely breast cancer then waiting for bloods should NOT delay referral.

Published data has shown that transgender women have a higher risk of breast cancer compared to men, and transgender men have a lower risk of breast cancer compared to women. In transgender women the risk of breast cancer is associated with hormone treatment. In cases of gender reassignment, it is important to provide sensitive and clinically appropriate care depending on individual circumstances and considering any hormone therapy involved. (Scottish Referral Guidelines for Suspected Cancer July 2025)

Referrals to the Breast Unit for men with USC are triaged in the same way and to the same timescale as USC referrals to the Breast Unit for women are triaged.

Gynaecomastia

Gynaecomastia is common, may be unilateral and is due to an imbalance of sex hormones.

Causes include:

• Physiological: puberty, old age
• Pharmacological: Alcohol, cannabis, opiates, steroids, protein supplements, antiandrogens, digoxin, spironolactone, omeprazole, allopurinol and many others.
• Systemic illness: Liver disease, renal disease, testicular issues, obesity, previous radiotherapy or chemotherapy

As per the SRGSC 2025 Gynaecomastia can be a feature of germ cell tumours. See below re examination and investigation to help rule out testicular cancer as a cause.

Predisposing causes can be address in Primary Care, and do not need referral to Breast Unit

Assessment

• Examine: Rule out discrete lumps or lymphadenopathy (that would require referral) rather than general swelling of breast tissue. Look for signs of systemic illness associated with gynaecomastia.
• Testicular examination should be performed to look for atrophy, absence or lump

If no obvious cause is found then consider blood tests for:

• Cr+Es, LFTs, LH, FSH, oestradiol, testosterone, prolactin, beta-HCG, AFP, TFTs
• In Primary Care can use grouped tests in ICE by selecting Gynaecomastia under the Endocrinology Tab. Only Cr+Es will need to be added on to this list.

Management

In those with persistent swelling, not improved by addressing underlying factors, and who wish intervention then medication can be trialled:

• Tamoxifen 10mg once daily for 3-9 months
• Anastrozole 1mg daily for 3 months

This is an unlicensed indication. It is most useful for recent onset gynaecomastia and usually improves breast sensitivity.  If prescription of a medication outwith its licensed indication is being considered, discussion with secondary care is an option, should this be felt necessary for the small number of patients who may benefit. 

Surgical intervention is considered via the exceptional aesthetic referral pathway via Plastic Surgery.

Please see this helpful video from CfSD about Breast Lesions in Men

Breast Lumps in Men

Men with a breast lump (with or without gynaecomastia) should be referred to Breast Clinic. Those with a clinically obvious lipoma may not need further investigation.

OY, LP & JB MAR 26