Gynaecomastia
Key points
An increase in the amount of breast gland tissue in boys
Usually resolves after 1 year, unless it develops after 17 years of age
Physiological vs Pathological
Pathological Gynaecomastia
Increase in oestrogen
Decrease in androgen
Both
Increase in oestrogen:
Tumours: Testis, Liver, Adrenal
Exogenous oestrogen
Hyperthyroidism
Excess aromatase
CAH
Decrease in Androgens: Hypogonadism
Defective synthesis
Androgen insensitivity
Associated conditions
Peutz-Jegher’s syndrome - Sertoli cell tumour
Li Fraumeni syndrome - Adrenocortical tumour
Hepatic failure
Renal failure
Simon Classification of Gynaecomastia
Grade 1: Small enlargement with no excess skin
Grade 2a: Moderate enlargement with no excess skin
Grade 2b: Moderate enlargement with excess skin
Grade 3: Marked enlargement with excess skin
History
Onset of puberty (early, normal, late)
Onset of gynaecomastia (before, during, after puberty)
• Progression (rapid is physiological)
• Pain
• Tenderness
• Discharge
Surgical history
• Cryptorchidism
• Hypospadias
Medications that can cause gynaecomastia - 'DISCO M'
Digoxin
Isoniazid
Spironolactone
Cimetidine
Oestrogens
Marijuana
Also antidepressants, digitalis, steroids
Family history
• Gynaecomastia
• DSD
Social history
• Food
• Cosmetics
Physical Examination
General Examination
Breast Examination
Abdominal Examination
Testicular Examination
Investigations
Ultrasound
Laboratory bloods
• FSH
• LH
• Androgens
• Oestrogens
• Liver function tests
Referrals
Endocrinologist
Psychologist
Medical management
Treatment of underlying pathology
Tamoxifen
Anastrozole
Reassurance
Surgical
Usually have to be 18 then apply for funding for surgery
May be eligible if causing severe psychological distress
Liposuction (power assisted and ultrasound assisted)
VASER (Vibration Amplification of Sound Energy at Resonance)
Fibrous elements (direct excision or arthroscopic shaver)
Reduction mammoplasty
Subtotal/Total mastectomy
Subcutaneous mastectomy:
Incision around border of areola - lower half
Remove breast tissue
Weigh excised tissue and compare amounts on each side to check symmetry
Compression dressing
Suction drain for 1 day
Page edited by Prof. Ashok Daya Ram MBBS, FRCS, FRCPS, FEBPS, FRCS (Paed Surgery), Consultant Paediatric and Neonatal Surgeon, Norfolk and Norwich University Hospital, Norwich, UK. June 2025
Page edited by Mrs Charnjit Seehra BSc. June 2025
References
Vandeven HA, Pensler JM. Gynecomastia. [Updated 2023 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK430812/