Gynaecomastia
Summary
Gynaecomastia is the benign proliferation of male breast glandular tissue, causing breast enlargement. It results from an imbalance between oestrogen and androgen activity at the breast tissue level (increased oestrogen effect or decreased androgen effect). It is common, affecting 30-60% of males at some point in life. Physiological gynaecomastia occurs at three life stages: Neonatal (Maternal oestrogen), Pubertal (Transient, ~60% of boys), and Elderly (Declining testosterone). Pathological causes include Drugs (Spironolactone, Digoxin, Cimetidine, Finasteride, Cannabis, Anabolic steroids), Liver disease (Reduced oestrogen metabolism), Thyrotoxicosis, Hypogonadism (Primary or Secondary), Testicular/Adrenal tumours (Oestrogen/hCG-secreting), and Klinefelter's Syndrome (47,XXY). Key investigation is clinical examination to exclude male breast cancer (Hard, eccentric, fixed mass ± skin/nipple changes). Blood tests include LH, FSH, Testosterone, Oestradiol, LFTs, TFTs, and USS Testes. Management involves treating the underlying cause, stopping offending drugs, and Tamoxifen (Anti-oestrogen) for painful gynaecomastia. Surgery (Mastectomy) is offered for fibrotic or cosmetically distressing cases. [1,2]
Clinical Pearls
Breast Cancer Exclusion First: Hard, Non-concentric, Fixed lump with skin/nipple changes = Concern for Malignancy. Male breast cancer is rare but occurs.
Drug History is Essential: Many drugs cause gynaecomastia. Always ask about Spironolactone, Digoxin, Finasteride, PPIs/H2 blockers, Cannabis, Anabolic steroids.
Pubertal Gynaecomastia is Normal: Transient, bilateral, often tender breast development in adolescent boys. Usually resolves in 6-24 months. Reassurance.
Testicular USS if Unexplained: Rule out testicular tumour (Leydig cell, hCG-secreting germ cell tumour) in unexplained gynaecomastia, especially with testicular mass or asymmetry.
Prevalence
- Very Common: 30-60% of males at some life stage.
- Pubertal: ~60% of boys aged 10-16 years.
- Elderly: Up to 70% in men aged >50 years.
Physiological Gynaecomastia (3 Peaks)
| Stage | Age | Mechanism |
|---|---|---|
| Neonatal | Birth | Transplacental maternal/placental oestrogens. Resolves in weeks. |
| Pubertal | 10-16 years | Transient imbalance (Oestrogen production peaks before Testosterone). Resolves in 6-24 months. |
| Elderly (Senescent) | >50 years | Declining Testosterone. Increased peripheral aromatisation of androgens to oestrogens (Adipose tissue). |
Mechanism
Oestrogen:Androgen Imbalance at Breast Tissue
- Increased Oestrogen: Exogenous (drugs, phytoestrogens), Increased production (Tumours, Liver disease), Increased aromatisation (Obesity).
- Decreased Androgen: Hypogonadism (Primary or Secondary), Androgen resistance, Drugs blocking androgens.
- Receptor Level: Increased oestrogen receptor sensitivity or Androgen receptor blockade.
Common Causes
| Category | Examples |
|---|---|
| Physiological | Neonatal, Pubertal, Senescent. |
| Drugs (Very Common) | Spironolactone (Anti-androgen), Digoxin (Oestrogen-like), Cimetidine (Anti-androgen), Finasteride/Dutasteride (5α-reductase inhibitors), PPIs, Ketoconazole, Anabolic Steroids (Aromatisation), Cannabis, Alcohol (Liver damage + Direct effect), Oestrogens, Metoclopramide/Domperidone (Hyperprolactinaemia). |
| Hypogonadism | Primary (Testicular failure – Klinefelter's, Torsion, Mumps orchitis). Secondary (Pituitary disease, Kallmann's). |
| Tumours | Testicular Tumours (Leydig cell – Oestrogen secreting; Germ cell – hCG secreting). Adrenal Tumours (Oestrogen/Androgen secreting). |
| Liver Disease (Cirrhosis) | Reduced oestrogen metabolism. Alcohol also has direct effect. |
| Hyperthyroidism | Increased SHBG → Reduced free Testosterone → Relative oestrogen excess. |
| Chronic Kidney Disease | Hypogonadism. |
| Androgen Insensitivity Syndrome | X-linked. Feminisation due to receptor defect. |
| Idiopathic | ~25%. No cause identified. |
| Condition | Key Features |
|---|---|
| Gynaecomastia (True) | Concentric, Rubbery disc of tissue behind nipple-areola. Mobile, Non-fixed. Usually bilateral (Can be unilateral). |
| Pseudogynaecomastia (Lipomastia) | Fatty tissue only (No glandular tissue). Obese patients. Soft, No discrete disc. |
| Male Breast Cancer | Hard, Fixed, Eccentric mass (Not behind nipple). Unilateral. Skin changes (Dimpling, Ulceration). Nipple retraction/discharge (Bloody). Lymphadenopathy. Risk: Klinefelter's, BRCA2. |
Symptoms
| Symptom | Notes |
|---|---|
| Breast Enlargement | Uni- or Bilateral. Often asymmetric. |
| Breast Tenderness | Common, especially in early/active phase. |
| Cosmetic Concern | Major reason for presentation, especially in adolescents. |
| Nipple Discharge | Rare. If bloody → Concern for malignancy. |
Signs
| Feature | Gynaecomastia | Pseudogynaecomastia | Breast Cancer |
|---|---|---|---|
| Tissue Type | Glandular disc palpable | Fatty only | Hard mass |
| Location | Concentric around nipple | Diffuse | Eccentric, Not centred on nipple |
| Consistency | Rubbery, Firm | Soft | Hard, Fixed |
| Skin/Nipple Changes | None | None | Dimpling, Retraction, Ulcer |
| Bilaterality | Often bilateral | Bilateral | Usually unilateral |
Examination Technique
Assess for Underlying Cause
Purpose: Exclude Malignancy + Identify Cause
| Investigation | Purpose |
|---|---|
| Clinical Examination | Most important. Distinguish Gynaecomastia vs Pseudogynaecomastia vs Cancer. |
| LH, FSH | Distinguish Primary (High) vs Secondary (Low/Normal) Hypogonadism. |
| Testosterone (Total + Free) | Low in Hypogonadism. |
| Oestradiol | Elevated in Oestrogen-secreting tumours. |
| βhCG | Elevated in hCG-secreting Germ Cell Tumours. |
| Prolactin | Elevated in Prolactinoma / Drug-induced hyperprolactinaemia. |
| LFTs | Liver disease. |
| TFTs | Hyperthyroidism. |
| U&E / eGFR | CKD. |
| Testicular Ultrasound | If testicular mass palpable or unexplained gynaecomastia (Exclude tumour). |
| Mammography / Breast USS | If clinical concern for malignancy (Hard mass, Eccentric). |
| Karyotype | If Klinefelter's suspected (XXY – Small testes, Tall, Infertility). |
Stepwise Approach
- Exclude Malignancy (Clinical).
- Review Drug History (Stop offenders).
- Baseline Bloods: LH, FSH, Testosterone, Oestradiol, βhCG, Prolactin, LFTs, TFTs.
- USS Testes if indicated.
Management Algorithm
MALE WITH BREAST ENLARGEMENT
↓
CLINICAL EXAMINATION
(Exclude Malignancy: Hard, Eccentric, Fixed, Skin Changes?)
┌────────────────┴────────────────┐
SUSPICIOUS FOR CANCER NOT SUSPICIOUS
↓ ↓
URGENT REFERRAL CONFIRM GYNAECOMASTIA
MAMMOGRAPHY / USS (vs Pseudogynaecomastia)
± BIOPSY ↓
REVIEW DRUG HISTORY
(Spironolactone, Digoxin, Cannabis, etc.)
┌────────────────┴────────────────┐
DRUG CAUSE NO DRUG CAUSE
↓ ↓
STOP/SUBSTITUTE DRUG BASELINE BLOODS
(If safe) LH, FSH, Testosterone,
Observe for Resolution Oestradiol, βhCG, Prolactin,
LFTs, TFTs
± USS Testes
↓
CAUSE IDENTIFIED?
┌────────────┴────────────┐
YES NO (IDIOPATHIC)
↓ ↓
TREAT CAUSE OBSERVATION
- Hypogonadism: TRT (Especially if Pubertal
- Hyperthyroidism: Rx – Usually resolves)
- Tumour: Surgery
↓
SYMPTOMATIC MANAGEMENT (If Persistent/Painful)
┌──────────────────────────────────────────────────────────┐
│ MEDICAL THERAPY (For Active, Tender Gynaecomastia) │
│ - TAMOXIFEN 10-20mg OD (SERM) │
│ - Most effective for Painful/Active gynaecomastia. │
│ - Off-label use. 3-6 month trial. │
│ - RALOXIFENE (Alternative SERM). │
│ - ANASTROZOLE (Aromatase Inhibitor) – Less evidence. │
└──────────────────────────────────────────────────────────┘
↓
REFRACTORY / FIBROTIC / COSMETIC CONCERN?
┌──────────────────────────────────────────────────────────┐
│ SURGICAL MANAGEMENT │
│ - SUBCUTANEOUS MASTECTOMY │
│ - If gynaecomastia is fibrotic (Long-standing, >2yrs)│
│ and will not respond to medical therapy. │
│ - Significant cosmetic/psychological distress. │
│ - ± LIPOSUCTION (For Pseudogynaecomastia component). │
└──────────────────────────────────────────────────────────┘
Treatment Summary
| Scenario | Management |
|---|---|
| Physiological (Pubertal) | Reassurance. Observation. Usually resolves in 6-24 months. |
| Drug-Induced | Stop/Substitute offending drug (If safe). |
| Underlying Cause | Treat cause (Hypogonadism → TRT, Hyperthyroidism → Rx, Tumour → Surgery). |
| Symptomatic/Active/Tender | Tamoxifen 10-20mg OD for 3-6 months. Effective in early/active phase. |
| Fibrotic/Long-Standing/Cosmetic | Surgery (Subcutaneous Mastectomy). Medical therapy less effective once fibrosed. |
When Medical Therapy Works
- Active Phase (Pain, tenderness, less than 12-24 months duration).
- Less effective once tissue becomes fibrotic (Usually >2 years).
| Complication | Notes |
|---|---|
| Psychological Distress | Significant in adolescents. Body image issues. Social embarrassment. |
| Underlying Malignancy (If Missed) | Male breast cancer. Testicular tumour. |
| Cosmetic Deformity | If long-standing and fibrotic. |
- Physiological (Pubertal): >90% resolve spontaneously within 2 years.
- Drug-Induced: Usually resolves on stopping drug (May take months).
- Pathological: Depends on underlying cause.
- Fibrotic Gynaecomastia: Unlikely to resolve with medical therapy. Surgery if intervention wanted.
Key Guidelines
| Guideline | Organisation | Key Recommendations |
|---|---|---|
| Endocrine Society Guidelines (2018) | Endocrine Society | Investigation pathway. Tamoxifen for symptomatic. Surgery for refractory. |
What is Gynaecomastia?
Gynaecomastia is the enlargement of breast tissue in males. It is caused by an imbalance of hormones (Oestrogen and Testosterone) and is very common. It is NOT the same as fat (Pseudogynaecomastia).
Is it serious?
Usually, no. Gynaecomastia itself is benign. However, it's important to check that it is not a sign of an underlying problem (like a hormone imbalance, liver disease, or rarely a tumour) and to rule out breast cancer (which is rare in men but can occur).
Why did I get it?
There are many causes:
- Normal/Physiological: Common in newborns, teenage boys, and older men.
- Medications: Some drugs can cause it (e.g., Spironolactone, Digoxin, Cannabis).
- Medical conditions: Liver disease, Thyroid problems, Hormone-producing tumours.
- Sometimes no cause is found (Idiopathic).
How is it treated?
- Stop any offending medication (if safe).
- Treat any underlying cause.
- Tablets (Tamoxifen): Can help if the breast is tender or early.
- Surgery: If the tissue has become hard (fibrotic) or is causing significant distress, surgery can remove it.
Primary Sources
- Kanakis GA, et al. EAU guidelines on male sexual dysfunction, infertility and gynaecomastia. Eur Urol. 2021.
- Braunstein GD. Gynecomastia. N Engl J Med. 2007;357(12):1229-37. PMID: 17881754.
Common Exam Questions
- Distinguish Gynaecomastia from Pseudogynaecomastia: "How do you distinguish true Gynaecomastia from Pseudogynaecomastia?"
- Answer: Gynaecomastia has a concentric rubbery disc of glandular tissue palpable behind the nipple. Pseudogynaecomastia is soft fatty tissue without a discrete disc.
- Red Flag for Malignancy: "What feature on examination raises concern for male breast cancer?"
- Answer: Hard, Fixed, Eccentric mass (Not centred on nipple), Skin dimpling/Ulceration, Nipple retraction/Bloody discharge, Axillary lymphadenopathy.
- Drug Causes (Name 3): "Name 3 drugs that cause Gynaecomastia."
- Answer: Spironolactone, Digoxin, Cimetidine (Also: Finasteride, Cannabis, Anabolic steroids, Metoclopramide).
- Medical Treatment: "First-line medical treatment for symptomatic Gynaecomastia?"
- Answer: Tamoxifen (SERM, Anti-oestrogen).
Viva Points
- Klinefelter's Syndrome (47,XXY): Tall stature, Small testes, Gynaecomastia, Infertility. Increased risk of male breast cancer.
- When Surgery is Needed: Long-standing (>2 years) fibrotic gynaecomastia won't respond to medical therapy.
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