GynaecomastiaBMJ 2016; 354 doi: https://doi.org/10.1136/bmj.i4833 (Published 22 September 2016) Cite this as: BMJ 2016;354:i4833
- Paul Thiruchelvam, clinical lecturer in surgery and Winston Churchill fellow1,
- Jonathan Neil Walker, consultant in endocrinology and diabetes2,
- Katy Rose, specialist trainee year 2 in paediatrics3,
- Jacqueline Lewis, consultant oncoplastic surgeon1,
- Ragheed Al-Mufti, consultant oncoplastic and reconstructive breast surgeon1
- 1Academic Department of Surgery, Imperial College NHS Trust, Charing Cross Hospital, London W6 8RF, UK
- 2Royal Devon and Exeter Foundation Trust, Exeter, UK
- 3Queen Charlotte’s and Chelsea Hospital, London, UK
- Correspondence to: P Thiruchelvam
What you need to know
Gynaecomastia typically results from an imbalance between the level or action of oestrogen and androgen
Physiological gynaecomastia is common in newborns, adolescents, and older men and most do not require investigation
Removal of the underlying cause often leads to resolution of gynaecomastia
Early treatment with tamoxifen (unlicensed) is the most effective medical option in men with symptoms
Surgery is the only effective treatment option once gynaecomastia becomes fibrotic
Gynaecomastia is the benign proliferation of glandular breast tissue in men. It is characterised by the presence of a palpable, firm, subareolar gland and ductal tissue (not fat) resulting in breast enlargement.1 2 Gynaecomastia occurs in 35% of men and is most prevalent between the ages of 50 and 69.3 4 5 6 7 In pseudogynaecomastia there is a lack of glandular proliferation, with increase in breast size due purely to excess adiposity.8 9 10 11 It can be difficult to differentiate gynaecomastia from pseudogynaecomastia, as some patients will have an element of both adiposity and glandular proliferation. This article highlights the assessment and treatment of gynaecomastia but does not cover the management of breast cancer in men.
Sources and selection criteria
We searched Medline and Embase from 1980 to date, limited to publications in English and to studies in men. Our search strategy used a combination of MeSH, textwords, and appropriate word variants of “gynaecomastia” or “gynecomastia” and “male breast disease”. We supplemented these sources with selected systematic reviews. Additional information cited includes evidence based guidelines and published consensus statements, where available.
What causes gynaecomastia?
Oestrogens directly stimulate the breast duct development of both sexes, whereas testosterone is a potent inhibitor of breast growth.12 13 14 Gynaecomastia occurs predominantly as a result of either an excess of oestrogens or oestrogen precursors or a reduction in androgens or impairment of their actions (fig 1⇓ …