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Breast tissue enlargement in men and pubertal boys is very common. Not unusual for a teenager to arrive with his parents to discuss this issue. Gynaecomastia is derived from Greek -mastos means women and Gynae we all know is a woman. This chart on Gynaecomastia on A4Medicine explains the pathophysiology and causes of gynaecomastia. A brief assessment is followed by some practical management tips. Which investigations to order are mentioned and currently, we do not have a guideline on management of gynaecomastia. Use of Tamoxifen is discussed with evidence of benefit in the Nottingham study

Benign proliferation of glandular breast tissue in men characterized by presence of rubbery or firm mass extending concentrically from the nipples Common – up to 35 % of men Most common disorder of male breast Can occur at any age but ↑ common in older men
Peak in pubertal boys Oestrogens are major hormones responsible for proliferation of breast tissue in both sexes whereas testosterone is a potent inhibitor of breast growth
 Can result from hormone imbalance- either an excess of oestrogens or oestrogen precursors or a reduction in androgens or impairment of their actions

Presentation-Presents usually with a swelling of the breast , often unilateral Can be tender ( proliferation of glandular tissue ) sometimes painful Size can vary from a small amount of extra tissue around nipple to prominent breasts Teenagers – body perception and self image are very important at this age and breast enlargement can be quite distressing Secondary gynaecomastia can present with associated symptoms for eg thyrotoxicosis , liver disease or renal disease

history-Age of onset and duration Any change in nipple size , pain , discharge H/O mumps , testicular trauma Illicit drug use 
( particularly in younger men explore illicit drug use and body building supplements ) Family history of gynaecomastia ( 58 % of patients with persistent pubertal gynaecomastia have a +ve family history ) H/o sexual dysfunction , infertility or hypogonadism Medications

Examination-Thorough examination of breasts
○ palpate all areas including nipple
○ compare and note uni or bilateral
○ use thumb and index finger- place over 
the outer and inner breast margins brought
 together in pinching movement
○ a diameter of under 2 cm is considered
to be within normal limits ; above 2 cm is consistent with gynaecomastia
○ concentric enlargement around areola or discoid mass underneath areola
 Check for nipple discharge or 
axillary lymphadenopathy

 Offer testicular examination
○ if h/o suggestive of hypogonadism
○ any suggestion of testicular mass
 General physical examination to look
for signs of hyperthyroidism 
liver disease and hypogonadism
 Check BMI and assess secondary sexual characters Refer urgently to
 r/o breast cancer if 
 unusual mass , distorted nipples or areola , skin abnormality or axillary lymphadenopathy 
found If testicular mass noticed arrange urgent US + refer Urology Cancer is 
diagnosed in about
 1 % of cases of gynaecomastia

Medical management will be ineffective if fibrosis has occurred
 In UK Danazol is licenced but use is limited due to weight gain which may exacerbate the condition
 Tamoxifen is the most widely used medical treatment
○ not licenced
○ improves breast pain and is more effective when gynaecomastia is < 4 cm
○ Nottingham used @ 20 mg/daily for physiological gynaecomastia duration 6-12 weeks- conclusion effective treatment for physiological gynaecomastia , especially lump type



A concise and informative leaflet from Hormone Health Network – can be useful to print if you do not suspect a serious underlying cause

A useful page from Boston Children’s Hospital

Paediatric Endocrinology factsheet from American Academy of Paediatrics – useful one page leaflet

Andrology Australia has produced a printable leaflet on Gynaecomastia which is quite handy

American Pediatric Surgical Association information for parents on gynecomastia


European Academy of Andrology clinical practice guidelines – gynaecomastia evaluation and management

The Journal of Clinical Endocrinology and Metabolism Approach to the patient with Gynecomastia

Indian Journal of Endocrinology and Metabolism Gynecomastia : Clinical Evaluation and management

Wish to know if you could refer for surgical treatment – consider reading this Surgical Treatment of Gynecomastia

A quick read from update for GPs  Epworth GP Update

NICE Breast Cancer USC guidance


  1. Ismail AA, Barth JH. Endocrinology of gynaecomastia. Ann Clin Biochem. 2001;38(Pt 6):596–607. doi:10.1258/0004563011900993
  2. Clinical updates Gynaecomastia BMJ 2016 ;354 : i4833
  3. Ersöz Hö, Onde ME, Terekeci H, Kurtoglu S, Tor H. Causes of gynaecomastia in young adult males and factors associated with idiopathic gynaecomastia. Int J Androl. 2002;25(5):312–316. doi:10.1046/j.1365-2605.2002.00374.x
  4. e-medicine Gynecomastia Updated March 2017
  5. Gynecomastia Am Fam Physician . 2012 Apr 1; 85 (7) : 716-722
  6. GP management of gynaecomastia Dr Kamilla Porter February 2012
  7. Gynaecomastia and breast cancer in men BMJ 2008 ; 336 : 709
  8. First Consult Gynaecomastia May 2012
  9. Management of physiological gynaecomastia with tamoxifen The Breast Vol 13 , Issue 1 , February 2004 , Pages 61-65
  10. Algorithm for clinical evaluation and surgical treatment of gynaecomastia Cordova, Adriana et al.Journal of Plastic, Reconstructive & Aesthetic Surgery, Volume 61, Issue 1, 41 – 49
  11. Breast cancer care booklet- Gynaecomastia Hughes , Mansel & Webester’s
  12. Benign Disorders and diseases of the Breast . third Edition Elsevier Ltd Nottinghamshire Gyanecomastis Guideline








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