Synopsis
Confirm true glandular breast enlargement, detect breast or testicular malignancy and endocrine disease, remove reversible causes, and treat persistent pain or distress through an appropriate breast pathway.
- True gynaecomastia is benign proliferation of glandular breast tissue, usually felt as a rubbery or firm concentric subareolar disc; adipose enlargement without gland is pseudogynaecomastia.
- Physiological gynaecomastia occurs in newborns, puberty and later life, but the age does not remove the need to investigate a suspicious eccentric mass or systemic clue.
- The mechanism is increased oestrogen effect relative to androgen action from gonadal failure, liver or thyroid disease, tumours, medicines or exogenous hormones.
Key red flags
A hard irregular eccentric mass, skin dimpling, nipple inversion, unilateral bloody discharge or axillary nodes is suspicious and needs urgent breast referral.
Investigation priorities
Distinguish gland, fat and suspicious masses and identify a gonadal source.
Management branches
A person presents with unilateral or bilateral breast swelling, tenderness or a lump.
- Clarify duration, pain, nipple change, weight change, puberty, sexual and fertility symptoms, organ disease, family cancer risk, radiotherapy, medicines, anabolic agents, alcohol and supplements.
- Examine both breasts and nodes and distinguish subareolar gland from diffuse fat or an eccentric lesion; examine testes and secondary sexual characteristics with consent.
Key medicines
Tamoxifen specialist treatmentUse only the short specialist-selected off-label course for recent painful proliferative gynaecomastia.
Testosterone replacementUse a licensed formulation and specialist-titrated regimen only after symptomatic hypogonadism is repeatedly confirmed.