Gynaecomastia

1. Clinical Overview

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—either increased oestrogen effect or decreased androgen effect. It is extremely common, affecting 32-65% of males at some point in life depending on age and definition criteria. [1,2]

Physiological gynaecomastia occurs at three life stages: Neonatal (transplacental maternal oestrogen exposure, resolves within weeks), Pubertal (transient oestrogen-androgen imbalance, affects ~60% of boys aged 10-16 years, usually resolves within 6-24 months), and Elderly/Senescent (declining testosterone with increased peripheral aromatisation, up to 70% of men > 50 years). [1,2]

Pathological causes include: Drug-Induced (accounts for 10-25% of all gynaecomastia): Spironolactone (anti-androgen effect, 10% incidence in heart failure trials), Digoxin (oestrogen-like activity), Cimetidine (anti-androgen), Finasteride/Dutasteride (5α-reductase inhibitors), PPIs, Metoclopramide/Domperidone (hyperprolactinaemia), Cannabis, Anabolic steroids (aromatisation to oestrogens), and alcohol. [3,4] Hypogonadism (Primary: testicular failure—Klinefelter syndrome, mumps orchitis, testicular torsion; Secondary: pituitary disease, Kallmann syndrome). Tumours: Testicular tumours (Leydig cell tumours secreting oestrogen, germ cell tumours secreting hCG), adrenal tumours. Liver Disease/Cirrhosis (reduced oestrogen metabolism plus increased SHBG). Hyperthyroidism (increased SHBG → reduced free testosterone → relative oestrogen excess). Chronic Kidney Disease (hypogonadism, reduced clearance). Idiopathic (~25% of cases). [1,2,5]

The most critical clinical task is exclusion of male breast cancer: hard, eccentric, fixed mass (not centred on nipple), skin changes (dimpling, ulceration), nipple retraction or bloody discharge, and axillary lymphadenopathy are red flags. Klinefelter syndrome (47,XXY) confers 19.2-fold increased risk of male breast cancer compared to general male population and 57.8-fold increased mortality. [6,7]

Investigations focus on: (1) Clinical examination to exclude malignancy and distinguish true gynaecomastia from pseudogynaecomastia (lipomastia); (2) Hormonal evaluation: LH, FSH, Total and Free Testosterone, Oestradiol, βhCG, Prolactin, LFTs, TFTs, U&E/eGFR; (3) Testicular ultrasound if testicular mass palpable or unexplained gynaecomastia; (4) Mammography/breast ultrasound ± biopsy if clinical concern for malignancy. [1,2]

Management depends on aetiology and chronicity. General principles: (1) Stop offending drugs (if safe to do so—drug-induced gynaecomastia resolves in weeks to months after cessation); (2) Treat underlying cause (testosterone replacement in hypogonadism, antithyroid treatment in hyperthyroidism, surgical excision of tumours); (3) Watchful waiting for physiological pubertal gynaecomastia (> 90% resolve spontaneously within 2 years). [1,2,8]

Medical therapy for symptomatic/active gynaecomastia: Tamoxifen 10-20 mg daily (selective oestrogen receptor modulator, SERM) for 3-6 months—most effective in early, tender, active-phase gynaecomastia (less than 12-24 months duration). Raloxifene (alternative SERM) and aromatase inhibitors (anastrozole, letrozole) have been used but with less consistent evidence in adolescents. [8,9]

Surgical management (subcutaneous mastectomy ± liposuction) is the treatment of choice for: long-standing, fibrotic gynaecomastia (> 2 years duration, unlikely to respond to medical therapy), refractory cases, and severe cosmetic/psychological distress. [1,2,8]

Clinical Pearls

Exclude Malignancy First: Hard, non-concentric, fixed lump with skin or nipple changes suggests male breast cancer. Klinefelter syndrome patients have substantially elevated breast cancer risk—maintain high index of suspicion.

Drug History is Essential: 10-25% of gynaecomastia is drug-induced. Always review medications, particularly spironolactone (10% incidence), digoxin, cimetidine, finasteride, PPIs, metoclopramide, cannabis, anabolic steroids, and alcohol.

Pubertal Gynaecomastia is Physiological: Affects ~60% of boys aged 10-16 years. Usually bilateral, often tender, and resolves spontaneously in > 90% within 2 years. Reassurance and watchful waiting are appropriate. Avoid unnecessary investigations unless atypical features present.

Testicular Examination is Mandatory: Palpate for testicular masses (Leydig cell tumours, hCG-secreting germ cell tumours) and assess testicular volume (hypogonadism, Klinefelter syndrome). USS testes if mass palpable or unexplained gynaecomastia.

Medical Therapy Works Best Early: Tamoxifen effective in active, tender, early-phase gynaecomastia (less than 12-24 months). Once tissue becomes fibrotic (> 2 years), medical therapy unlikely to be effective—surgery is treatment of choice.

Distinguish True Gynaecomastia from Pseudogynaecomastia: True gynaecomastia = concentric rubbery disc of glandular tissue palpable behind nipple. Pseudogynaecomastia (lipomastia) = soft fatty tissue without discrete disc. Management differs.

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2. Epidemiology

Prevalence

Gynaecomastia is extremely common, with prevalence varying by age:

Physiological Gynaecomastia: Three Peaks

Geographical and Ethnic Variation

• No significant ethnic variation reported in large epidemiological studies. [1]
• Higher prevalence in obese populations due to increased peripheral aromatisation in adipose tissue. [2]

Temporal Trends

• Incidence of drug-induced gynaecomastia rising due to increased use of medications with oestrogenic/anti-androgenic effects (spironolactone, finasteride, PPIs). [3,4]
• Recognition and diagnosis improved with clinical awareness.

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3. Aetiology and Pathophysiology

Fundamental Mechanism: Oestrogen-Androgen Imbalance

Breast tissue responds to oestrogen (proliferative) and androgen (inhibitory). Gynaecomastia develops when the ratio of oestrogen to androgen activity at the breast tissue level is increased. This can occur via three broad mechanisms: [1,2]

1. Increased Oestrogen Effect:

   • Increased oestrogen production (tumours, liver disease, obesity).
   • Exogenous oestrogen exposure (drugs, environmental).
   • Increased peripheral aromatisation of androgens to oestrogens (adipose tissue, drugs that enhance aromatase).

2. Decreased Androgen Effect:

   • Hypogonadism (reduced testosterone production).
   • Androgen receptor blockade or resistance (drugs, androgen insensitivity syndrome).
   • Reduced bioavailable testosterone (increased SHBG).

3. Mixed/Multifactorial:

   • Combination of increased oestrogen and decreased androgen (e.g., liver disease, hyperthyroidism, chronic kidney disease).

Molecular Pathophysiology

Exam Detail: Oestrogen Receptor Activation in Breast Tissue:

• Male breast tissue contains oestrogen receptors (ER-α and ER-β).
• Oestrogen binding induces ductal proliferation and stromal hypertrophy.
• Normal male breast tissue is quiescent due to low oestrogen:androgen ratio.
• When oestrogen effect increases (or androgen effect decreases), ductal epithelium proliferates and periductal stroma becomes oedematous and fibrotic over time. [2]

Aromatase Enzyme:

• Aromatase (CYP19A1) converts androgens (testosterone, androstenedione) to oestrogens (oestradiol, oestrone).
• Expressed in adipose tissue, testes, liver, breast tissue.
• Increased aromatase activity in obesity, ageing, liver disease, and certain tumours causes increased oestrogen synthesis. [2,5]

Sex Hormone-Binding Globulin (SHBG):

• SHBG binds testosterone and oestradiol but has higher affinity for testosterone.
• Conditions that increase SHBG (hyperthyroidism, liver disease, ageing) reduce free (bioavailable) testosterone more than oestrogen → relative oestrogen excess. [2,5]

Androgen Receptor Signalling:

• Androgens inhibit breast tissue proliferation.
• Drugs that block androgen receptors (spironolactone, cimetidine, bicalutamide, flutamide) or reduce androgen synthesis (5α-reductase inhibitors: finasteride, dutasteride) → decreased androgen effect → gynaecomastia. [3,4]

Prolactin:

• Hyperprolactinaemia (pituitary prolactinoma, drugs: metoclopramide, domperidone, antipsychotics) can cause gynaecomastia by:
  • Suppressing gonadotropins → hypogonadism.
  • Direct effect on breast tissue (synergistic with oestrogen). [2]

Causes of Gynaecomastia (Systematic Classification)

1. Physiological (60-70% of all cases)

2. Drug-Induced (10-25% of all cases) [3,4]

High-Risk Medications:

Clinical Pearl: Spironolactone-Induced Gynaecomastia: In the RALES trial (Randomised Aldactone Evaluation Study), spironolactone 25 mg daily in severe heart failure caused gynaecomastia or breast pain in 10% of men vs 1% placebo (Pless than 0.001). [4] The selective mineralocorticoid receptor antagonist eplerenone has no anti-androgen activity and does not cause gynaecomastia—consider switching if spironolactone-induced gynaecomastia develops in heart failure patients.

3. Hypogonadism (8-10% of cases) [1,2]

Exam Detail: Klinefelter Syndrome (47,XXY):

• Most common genetic cause of primary hypogonadism (1 in 500-1000 males).
• Clinical features: Tall stature, eunuchoid proportions (arm span > height), small, firm testes (less than 5 mL volume), gynaecomastia (~80%), reduced facial/body hair, infertility (azoospermia), learning difficulties (variable).
• Breast cancer risk: 19.2-fold increased incidence, 57.8-fold increased mortality compared to general male population. Risk still ~70% lower than in females. [6,7]
• Hormonal profile: High LH, High FSH, Low testosterone (primary testicular failure).
• Karyotype: 47,XXY (classic), mosaic 47,XXY/46,XY (milder phenotype).
• Gynaecomastia in Klinefelter syndrome is due to: (1) Low testosterone; (2) Increased aromatisation; (3) Increased SHBG; (4) Relative oestrogen excess. [6,7]

4. Tumours (3-5% of cases) [1,2]

Clinical Pearl: Testicular Examination is Mandatory: Always examine testes in gynaecomastia. Asymmetric or hard testicular mass → urgent USS testes + tumour markers (βhCG, AFP). Testicular tumours present with gynaecomastia in 10-20% of Leydig cell tumours and 7% of non-seminomatous germ cell tumours. [2]

5. Systemic Diseases (10-15% of cases) [1,2,5]

6. Androgen Insensitivity Syndrome (AIS) [2]

7. Idiopathic Gynaecomastia (25% of cases) [1,2]

• No identifiable cause after thorough investigation.
• Diagnosis of exclusion.
• Likely due to subtle hormonal imbalances not detected by standard assays.
• Increased peripheral aromatase activity hypothesised.
• Management: observation, symptomatic treatment (tamoxifen if painful), surgery if cosmetically distressing.

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4. Differential Diagnosis

The key differential diagnoses to distinguish from true gynaecomastia are:

1. Pseudogynaecomastia (Lipomastia)

Definition: Breast enlargement due to adipose tissue deposition without glandular proliferation.

2. Male Breast Cancer

Critical red flags to distinguish from gynaecomastia:

Clinical Pearl: Red Flag Triad for Male Breast Cancer:

1. Hard, Fixed, Eccentric mass (not centred on nipple).
2. Skin or nipple changes (dimpling, retraction, bloody discharge).
3. Lymphadenopathy.

Any ONE of these features → Urgent referral to breast surgery → Mammography/USS ± core biopsy. [7]

3. Other Breast Lumps

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5. Clinical Presentation

Symptoms

Signs on Examination

Breast Examination Technique

1. Patient Positioning: Supine, arms behind head (exposes breast tissue).
2. Inspection: Asymmetry, skin changes (dimpling, erythema, ulceration), nipple retraction.
3. Palpation:
   • Use fingers spread flat, starting at periphery, moving towards nipple.
   • Gynaecomastia: Palpable concentric rubbery disc of glandular tissue radiating from nipple-areola complex.
   • Pseudogynaecomastia: Soft fatty tissue, no discrete disc.
   • Measure diameter (if tracking resolution/progression): e.g., 3 cm disc.
4. Nipple: Assess for retraction, discharge (express gently if history of discharge).
5. Lymph Nodes: Palpate axillary, infraclavicular, supraclavicular nodes.

Gynaecomastia Features

Histological/Temporal Stages (Clinical Correlation)

Clinical Pearl: Timing of Medical Therapy Matters: Tamoxifen is most effective in the florid/active phase (less than 12 months). Once gynaecomastia becomes fibrotic (> 2 years), medical therapy has minimal effect—surgery is the treatment of choice for long-standing, fibrotic gynaecomastia. [1,8,9]

Systemic Examination (Assess for Underlying Cause)

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6. Investigations

The goals of investigation are: (1) Exclude malignancy; (2) Identify underlying cause (potentially reversible); (3) Guide management.

Stepwise Investigative Approach

Step 1: Clinical Examination (MOST IMPORTANT)

• Distinguish true gynaecomastia vs pseudogynaecomastia vs breast cancer.
• Palpate testes (size, masses).
• Assess for signs of hypogonadism, liver disease, hyperthyroidism.

Step 2: Review Drug History

• Systematic review of all medications and substances (including over-the-counter, herbal, recreational drugs).
• Identify high-risk drugs (see Section 3.2).
• Trial of drug cessation (if safe) before extensive investigations, especially in typical pubertal or senescent gynaecomastia.

Step 3: Baseline Hormonal and Biochemical Panel

Order if:

• Atypical age (prepubertal, young adult).
• Rapid onset/progression.
• Severe gynaecomastia.
• Signs of hypogonadism or systemic disease.
• Persistent beyond expected resolution time (pubertal > 2 years).

Clinical Pearl: Hormonal Panel NOT Routinely Required in Typical Pubertal or Senescent Gynaecomastia:

• Pubertal boys (10-16 years) with bilateral, tender, concentric gynaecomastia and normal testicular volume → physiological. Reassurance and observation—no investigations unless atypical features (unilateral, hard mass, rapid progression, prepubertal, testicular abnormality).
• Elderly men (> 50 years) with bilateral, non-tender gynaecomastia, normal clinical examination, and no drug cause → senescent. Observation—investigations if atypical.

Investigations ARE indicated in:

• Prepubertal or young adult (non-pubertal age).
• Rapid onset/progression.
• Severe gynaecomastia.
• Unilateral (exclude cancer).
• Testicular mass or abnormality.
• Signs of hypogonadism, liver disease, hyperthyroidism.

Step 4: Testicular Ultrasound (USS Testes)

Indications:

• Palpable testicular mass or asymmetry.
• Elevated βhCG or AFP.
• Unexplained gynaecomastia (no drug cause, normal hormonal panel).
• Young adult with rapid-onset gynaecomastia (exclude tumour).

Findings:

• Testicular tumour: Hypoechoic mass, vascular, irregular. Urgent urology referral + tumour markers. [2]
• Small testes (less than 5 mL volume): Klinefelter syndrome, primary hypogonadism. [2]

Step 5: Breast Imaging (Mammography / Breast Ultrasound)

Indications:

• Clinical suspicion of male breast cancer: hard, eccentric, fixed mass; skin/nipple changes; bloody discharge; lymphadenopathy.
• Age > 50 years + unilateral, non-tender, eccentric mass.
• Rapid growth.
• Klinefelter syndrome (high breast cancer risk).

Findings:

• Gynaecomastia: Dendritic, flame-shaped, subareolar symmetrical density (mammography). Hypoechoic tissue with ductal structures (USS). [1]
• Male breast cancer: Irregular, spiculated mass (mammography). Hypoechoic mass with irregular borders, vascular (USS). Proceed to core needle biopsy. [7]

Clinical Pearl: Do NOT delay biopsy if suspicion of cancer is high: If clinical examination suggests malignancy (hard, eccentric, fixed, skin/nipple changes, lymphadenopathy), proceed directly to core needle biopsy rather than imaging alone. Imaging may be falsely reassuring. [7]

Step 6: Karyotype

Indications:

• Clinical features of Klinefelter syndrome: small, firm testes (less than 5 mL), tall stature, eunuchoid proportions, gynaecomastia, infertility/azoospermia.
• Hormonal panel showing primary hypogonadism (high LH/FSH, low testosterone) in young adult.

Result:

• 47,XXY (classic Klinefelter syndrome).
• Mosaic 47,XXY/46,XY (milder phenotype). [6]

Step 7: Further Imaging (if indicated)

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7. Management

Management of gynaecomastia is individualised based on:

1. Aetiology (physiological vs pathological).
2. Duration (active/early vs fibrotic/long-standing).
3. Severity (degree of breast enlargement).
4. Symptoms (pain/tenderness).
5. Patient preference (cosmetic concern, psychological impact).

Management Principles

1. Exclude Malignancy First: Clinical examination ± imaging ± biopsy.
2. Identify and Treat Underlying Cause: Stop drugs, treat hypogonadism, manage systemic disease, excise tumours.
3. Observation for Physiological Gynaecomastia: Pubertal (> 90% resolve within 2 years), senescent (observation unless symptomatic).
4. Medical Therapy for Active/Symptomatic Gynaecomastia: Tamoxifen (first-line), aromatase inhibitors (second-line).
5. Surgical Therapy for Fibrotic/Refractory/Cosmetic Gynaecomastia: Subcutaneous mastectomy ± liposuction.

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7.1. Management Algorithm

              MALE WITH BREAST ENLARGEMENT
                        ↓
              CLINICAL EXAMINATION
              (Breast, Testes, Systemic)
                        ↓
        ┌───────────────┴───────────────┐
    SUSPICIOUS FOR                 NOT SUSPICIOUS
    MALIGNANCY                      FOR MALIGNANCY
        ↓                               ↓
    URGENT REFERRAL          CONFIRM GYNAECOMASTIA
    TO BREAST SURGERY        (vs Pseudogynaecomastia)
    - Mammography                     ↓
    - Breast USS              PSEUDOGYNAECOMASTIA?
    - Core Biopsy                     ├─ YES → Weight Loss
        ↓                             │         Liposuction (cosmetic)
    MANAGE AS MALE                    │
    BREAST CANCER                     └─ NO → TRUE GYNAECOMASTIA
                                              ↓
                                    REVIEW DRUG HISTORY
                             ┌──────────────┴───────────────┐
                       DRUG-INDUCED                  NO DRUG CAUSE
                             ↓                              ↓
                       STOP/SUBSTITUTE DRUG        BASELINE INVESTIGATIONS
                       (If safe to do so)          - LH, FSH, Testosterone
                       - Spironolactone → Eplerenone  - Oestradiol, βhCG
                       - Cimetidine → PPI/Ranitidine  - Prolactin
                       - Finasteride → Stop           - LFTs, TFTs, U&E
                       - Antipsychotic → Switch       - ± USS Testes
                       - Anabolic steroids → Stop     - ± Karyotype (if Klinefelter suspected)
                             ↓                              ↓
                       OBSERVE 3-6 MONTHS          CAUSE IDENTIFIED?
                       (Resolution expected)     ┌────────┴────────┐
                             ↓                  YES               NO
                       Resolution?               ↓                ↓
                       YES → Discharged     TREAT CAUSE      IDIOPATHIC
                       NO → See below       - Hypogonadism   GYNAECOMASTIA
                                              → TRT              ↓
                                            - Hyperthyroidism  OBSERVATION
                                              → Antithyroid    (Especially if
                                            - Testicular tumour pubertal or
                                              → Orchidectomy   senescent)
                                            - Prolactinoma       ↓
                                              → Cabergoline    Persistent?
                                            - Liver disease    Symptomatic?
                                              → Manage          ↓
                                                          See below ↓
                        ┌────────────────────────────────────────────┘
                        ↓
              IS GYNAECOMASTIA SYMPTOMATIC
              OR COSMETICALLY DISTRESSING?
            ┌──────────────┴──────────────┐
           NO                            YES
            ↓                              ↓
      OBSERVATION                    DURATION?
      - Pubertal: Reassure         ┌──────┴──────┐
        (> 90% resolve in 2 yrs)   less than 12 months   > 12-24 months
      - Senescent: Accept         (ACTIVE)      (FIBROTIC)
                                       ↓              ↓
                                  MEDICAL THERAPY  MEDICAL THERAPY
                                  (Tamoxifen)      UNLIKELY EFFECTIVE
                                       ↓                  ↓
                           TAMOXIFEN 10-20 mg OD   SURGICAL THERAPY
                           for 3-6 months          (Subcutaneous Mastectomy
                                  ↓                 ± Liposuction)
                           Resolution?                   ↓
                     ┌────────┴────────┐           Cosmetically
                    YES              NO             acceptable result
                     ↓                ↓             > 95% satisfaction
                 Discharged      - Continue Tamoxifen
                                  up to 9-12 months
                                 - Consider Surgery
                                 - Consider Raloxifene
                                   (alternative SERM)

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7.2. Specific Management Strategies

7.2.1. Physiological Gynaecomastia

7.2.2. Drug-Induced Gynaecomastia

First-Line: Stop or substitute offending drug (if safe to do so).

Timeline: Drug-induced gynaecomastia typically resolves within weeks to months after cessation, but may take up to 6 months. If persistent beyond 6 months after stopping drug → consider medical therapy (tamoxifen) or surgery. [3]

7.2.3. Pathological Causes: Treat Underlying Disease

Clinical Pearl: Testosterone Replacement in Hypogonadism May NOT Resolve Established Gynaecomastia: While TRT restores androgen levels and may prevent further gynaecomastia, long-standing, fibrotic gynaecomastia is unlikely to regress. Additionally, exogenous testosterone can be aromatised peripherally to oestrogen, potentially worsening gynaecomastia in susceptible individuals. Monitor breast tissue during TRT initiation. Consider co-administration of aromatase inhibitor (anastrozole) in selected cases, though evidence limited. [1,2]

7.2.4. Medical Therapy for Symptomatic Gynaecomastia

Indications:

• Active, tender, early-phase gynaecomastia (less than 12 months duration).
• Persistent gynaecomastia after treating underlying cause.
• Patient preference (non-surgical option).

NOT indicated:

• Asymptomatic, non-distressing gynaecomastia.
• Long-standing, fibrotic gynaecomastia (> 2 years)—unlikely to respond.

First-Line: Tamoxifen (Selective Oestrogen Receptor Modulator, SERM)

Exam Detail: Evidence for Tamoxifen in Gynaecomastia:

• RCT (Khan et al., 2011): Tamoxifen 20 mg daily for 3 months in 60 adolescent boys with pubertal gynaecomastia. Complete resolution in 80%, partial response in 15%, no response in 5%. Significantly superior to placebo. [9]
• Systematic Review (2014): Tamoxifen reduces breast volume by 30-50% in most patients with early-phase gynaecomastia. Less effective in fibrotic cases. [8]

Off-Label Use: Tamoxifen is not licensed for gynaecomastia in most countries (off-label use). Discuss with patient. Use in adolescents requires informed consent.

Second-Line: Raloxifene (Alternative SERM)

Aromatase Inhibitors (AI): Anastrozole, Letrozole

Clinical Pearl: Tamoxifen is FIRST-LINE medical therapy for symptomatic gynaecomastia. Aromatase inhibitors have theoretical advantages but inconsistent clinical evidence and concerns regarding growth plate effects in adolescents. Reserve AI for adult males with refractory gynaecomastia. [8,9]

7.2.5. Surgical Therapy

Indications:

• Long-standing, fibrotic gynaecomastia (> 2 years duration)—unlikely to respond to medical therapy.
• Refractory to medical therapy (tamoxifen/raloxifene trial failed).
• Severe cosmetic or psychological distress (body image issues, social embarrassment).
• Patient preference (definitive treatment).

Surgical Options:

Pre-Operative Considerations:

• Exclude malignancy (imaging ± biopsy if any suspicion).
• Stop anticoagulants/antiplatelets (if safe).
• Counsel patient on expectations, scarring, potential asymmetry.
• Realistic goals (near-flat chest, minimal scarring).

Post-Operative Care:

• Compression garment for 4-6 weeks (reduce seroma, haematoma, optimise contour).
• Avoid strenuous exercise for 6 weeks.
• Monitor for complications (haematoma, seroma, infection).
• Histology (exclude malignancy, confirm gynaecomastia).

Outcomes:

• > 95% patient satisfaction in most series. [1,8]
• Low recurrence (less than 5%) if adequate excision. [1,8]
• Significant improvement in quality of life, body image, self-esteem, especially in adolescents. [8]

Clinical Pearl: Surgery is the ONLY definitive treatment for fibrotic gynaecomastia. Subcutaneous mastectomy via periareolar incision provides excellent cosmetic results with minimal scarring. Avoid delaying surgery in young males with severe psychological distress—early surgery (after 2 years of observation or failed medical therapy) can significantly improve quality of life. [1,8]

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7.3. Management by Clinical Scenario

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8. Complications

8.1. Psychological Complications

Clinical Pearl: Do NOT underestimate psychological impact of gynaecomastia in adolescents: Even if physiological, significant body image distress can warrant active management (tamoxifen or surgery after 2 years) rather than prolonged observation. Discuss options with patient and family. [8]

8.2. Underlying Malignancy (If Missed)

Prevention: Always examine testes + exclude malignancy clinically in all gynaecomastia presentations. Investigate atypical features (unilateral, hard, eccentric, rapid progression, testicular mass).

8.3. Cosmetic Deformity

• Long-standing, untreated gynaecomastia → permanent fibrotic enlargement.
• Cosmetic concern, psychological distress.
• Surgery is only solution once fibrotic.

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9. Prognosis and Outcomes

9.1. Natural History by Aetiology

9.2. Response to Medical Therapy (Tamoxifen)

Conclusion: Early intervention with tamoxifen (less than 12 months) has highest success rate. Surgery is preferred for fibrotic gynaecomastia (> 2 years). [8,9]

9.3. Surgical Outcomes

• > 95% patient satisfaction after subcutaneous mastectomy. [1,8]
• Low recurrence rate (less than 5%) if adequate glandular tissue excision. [1,8]
• Significant improvement in quality of life, body image, self-esteem. [8]
• Complications rare: Haematoma (2-5%), seroma (5%), infection (less than 2%), nipple necrosis (rare less than 1%), asymmetry (5-10%, may require revision). [1,8]

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10. Prevention

10.1. Primary Prevention

• Avoid unnecessary medications known to cause gynaecomastia (see Section 3.2).
• Screen for hypogonadism in at-risk populations (Klinefelter syndrome, mumps orchitis, chemotherapy survivors) → early TRT may prevent gynaecomastia.
• Weight management (obesity increases peripheral aromatisation).
• Avoid anabolic steroid abuse (counselling in gyms, sports).

10.2. Secondary Prevention (Early Detection)

• Regular breast examination in high-risk populations: Klinefelter syndrome (monitor for breast cancer), patients on high-risk medications (spironolactone, finasteride, antipsychotics).
• Patient education: Report breast changes early (especially hard lumps, skin changes, bloody discharge).

10.3. Tertiary Prevention (Prevent Progression/Complications)

• Early medical therapy (tamoxifen) in active-phase gynaecomastia prevents fibrosis and need for surgery.
• Timely surgery in fibrotic gynaecomastia prevents prolonged psychological distress.

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11. Evidence and Guidelines

Key Guidelines

Exam Detail: EAA 2019 Guidelines—Statements and Recommendations (summarised): [1]

1. S1: Gynecomastia (GM) is benign proliferation of glandular tissue in males.
2. S2: GM of infancy is common, resolves spontaneously (typically within 1 year).
3. S3: GM of puberty is common, resolves spontaneously (majority within 1-2 years).
4. S4: GM of adulthood is more prevalent in elderly. Underlying pathology in 45-50% of cases.
5. S5: Assessment should detect underlying pathology, reversible causes (drugs), and discriminate from breast cancer.

Recommendations:

• R1: Medical history should include: onset, duration, symptoms, drug history, systemic symptoms (weight loss, testicular mass, headache, visual changes).
• R2: Physical examination: breast (palpate for glandular disc, exclude malignancy), genitalia (testicular volume, masses), signs of systemic disease (liver, thyroid).
• R3: Laboratory tests: LH, FSH, testosterone, oestradiol, SHBG, βhCG, prolactin, LFTs, TFTs, renal function.
• R4: Testicular ultrasound if: testicular mass palpable, unexplained GM, elevated βhCG.
• R5: Breast imaging (mammography, USS) if clinical concern for malignancy. Core biopsy if suspicious lesion.
• R6: Karyotype if Klinefelter syndrome suspected.
• R7: Watchful waiting recommended after treatment of underlying pathology or discontinuation of offending drugs.
• R8: Testosterone treatment should be offered to men with proven testosterone deficiency (hypogonadism).
• R9: Use of SERMs (tamoxifen, raloxifene) and aromatase inhibitors is not justified in general (limited evidence, off-label, side effects). However, can be considered in selected symptomatic cases (off-label use, shared decision-making).
• R10: Surgical treatment (subcutaneous mastectomy) is the therapy of choice for patients with long-lasting gynecomastia (> 2 years, fibrotic, refractory to medical therapy, or severe cosmetic/psychological distress).

GRADE Evidence Quality: Most recommendations are based on low-quality evidence (observational studies, case series). Limited high-quality RCTs for medical therapies. Surgical outcomes based on case series (high patient satisfaction but no RCTs comparing surgery vs observation). [1]

Landmark Studies

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12. Patient and Layperson Explanation

What is Gynaecomastia?

Gynaecomastia (sometimes spelled "gynecomastia") is enlargement of the breast tissue in males. It is caused by an imbalance of hormones (oestrogen and testosterone) in the body. It is very common, affecting up to 60% of males at some point in life.

Is it the same as having "man boobs" or being overweight?

No. There are two types of male breast enlargement:

• True gynaecomastia: This is caused by actual breast gland tissue growing. You can feel a firm, rubbery disc of tissue behind the nipple.
• Pseudogynaecomastia (or "lipomastia"): This is just extra fat in the chest area, common in overweight or obese men. There is no gland tissue.

Your doctor can tell the difference by examining you.

Why does gynaecomastia happen?

There are many reasons:

1. Normal/physiological (not due to disease):

   • Newborn babies: Caused by the mother's hormones. Goes away in a few weeks.
   • Teenage boys (puberty): Affects about 60% of boys aged 10-16. It happens because hormone levels are changing during puberty. It usually goes away on its own within 1-2 years.
   • Older men (over 50): Testosterone levels naturally decline with age, and this can cause breast tissue to grow.

2. Medications: Some medicines can cause gynaecomastia, such as:

   • Spironolactone (a "water tablet" for heart failure or high blood pressure).
   • Finasteride (for enlarged prostate or hair loss).
   • Digoxin (for heart conditions).
   • Cimetidine (for stomach acid).
   • Anabolic steroids (used illegally by bodybuilders).
   • Cannabis (marijuana).
   • Certain antipsychotic medications.

3. Medical conditions:

   • Low testosterone (hypogonadism): The testicles don't produce enough testosterone.
   • Klinefelter syndrome: A genetic condition where men are born with an extra X chromosome (47,XXY instead of 46,XY). This causes low testosterone and small testicles.
   • Liver disease (cirrhosis): The liver normally breaks down oestrogen. If the liver is damaged, oestrogen levels build up.
   • Overactive thyroid (hyperthyroidism).
   • Tumours: Rarely, tumours in the testicles or adrenal glands can produce hormones that cause gynaecomastia.

4. No clear cause (idiopathic): In about 1 in 4 men, doctors can't find a specific cause.

Is gynaecomastia serious? Could it be cancer?

Gynaecomastia itself is not cancer and is not dangerous. However, it's important to see a doctor to:

• Make sure it's not a sign of an underlying medical problem (like low testosterone, liver disease, or a tumour).
• Rule out male breast cancer (which is rare but can happen).

Red flags that might suggest breast cancer (see a doctor urgently if you notice these):

• A hard lump that is not centred on the nipple (off to one side).
• Skin changes (dimpling, puckering, redness, sores).
• Nipple changes (pulling in, bloody discharge).
• Lumps in the armpit (lymph nodes).

Male breast cancer is very rare (less than 1% of all breast cancers), but it is more common in men with Klinefelter syndrome.

How is gynaecomastia diagnosed?

Your doctor will:

1. Ask about your symptoms and medical history (including medications).
2. Examine your breasts and testicles.
3. Blood tests (if needed): To check hormone levels (testosterone, oestrogen, LH, FSH), liver function, thyroid function, and other tests.
4. Ultrasound scan of the testicles (if needed): To check for tumours.
5. Breast imaging (mammogram or ultrasound) (if concerned about cancer).

How is gynaecomastia treated?

Treatment depends on the cause and how long you've had it:

1. Observation (watchful waiting):

   • If you're a teenager, gynaecomastia usually goes away on its own within 1-2 years. Your doctor will reassure you and monitor you.
   • If you're an older man with mild gynaecomastia that doesn't bother you, you may just be monitored.

2. Stop the medication (if it's drug-induced):

   • If a medication is causing it (e.g., spironolactone, finasteride), your doctor may stop or change the medication. The gynaecomastia should improve over weeks to months.

3. Treat the underlying cause:

   • Low testosterone: Testosterone replacement therapy.
   • Overactive thyroid: Medication to control the thyroid.
   • Tumour: Surgery to remove the tumour.

4. Medication (tamoxifen):

   • A tablet called tamoxifen can help reduce breast tissue if the gynaecomastia is early (less than 1-2 years) and causing pain or distress.
   • Tamoxifen is usually taken for 3-6 months.
   • It works best in the early stages. Once the tissue becomes hard and fibrous (after 2+ years), tamoxifen doesn't work well.

5. Surgery:

   • If the gynaecomastia is long-standing (more than 2 years), doesn't respond to medication, or is causing significant distress, surgery can remove the breast tissue.
   • The operation is called subcutaneous mastectomy. The surgeon removes the gland tissue through a small cut around the nipple.
   • Over 95% of men are satisfied with the results.
   • Sometimes liposuction is also used to remove fat.

Will gynaecomastia come back after treatment?

• If caused by medication, it usually doesn't come back after you stop the medication.
• If caused by puberty, it rarely comes back once it's gone.
• If you have surgery, the chance of it coming back is very low (less than 5%), as long as the gland tissue is fully removed.
• If you have an ongoing medical condition (like low testosterone or liver disease), the gynaecomastia may persist unless the underlying condition is treated.

What should I do if I'm worried about gynaecomastia?

• See your GP (family doctor). They will examine you and decide if you need blood tests or scans.
• Don't be embarrassed. Gynaecomastia is very common and your doctor is used to seeing it.
• Seek urgent medical advice if you notice:
  • A hard lump in the breast (especially if it's off to one side).
  • Skin or nipple changes.
  • Bloody discharge from the nipple.

Key Takeaways

• Gynaecomastia is very common (affects up to 60% of males).
• It's usually harmless (not cancer).
• In teenagers, it almost always goes away on its own within 1-2 years.
• Medications are a common cause—your doctor may change your medication.
• Treatment options include: observation, stopping medications, tablets (tamoxifen), or surgery.
• See a doctor urgently if you notice a hard lump, skin changes, or bloody discharge (could be breast cancer).

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13. Examination Focus

Common Viva Questions and Model Answers

Q1: How do you distinguish true gynaecomastia from pseudogynaecomastia on clinical examination?

Model Answer:

• Patient position: Supine, arms behind head.
• Palpation technique: Place fingers flat, start at periphery, move towards nipple.
• True gynaecomastia: Palpable concentric, rubbery, firm disc of glandular tissue radiating from the nipple-areola complex. The disc is mobile, not fixed to skin or chest wall. Often tender in active phase.
• Pseudogynaecomastia (lipomastia): Soft fatty tissue without a discrete glandular disc. Diffuse breast enlargement. Common in obese patients (BMI > 30).
• Clinical significance: True gynaecomastia requires investigation for underlying causes (drugs, hypogonadism, tumours, systemic disease). Pseudogynaecomastia is managed with weight loss ± liposuction (cosmetic).

Q2: What are the red flag features on examination that suggest male breast cancer rather than benign gynaecomastia?

Model Answer: Red flags for male breast cancer:

1. Hard, fixed, eccentric mass (not centred on nipple). Asymmetric, unilateral.
2. Skin changes: Dimpling, peau d'orange, erythema, ulceration.
3. Nipple changes: Retraction, inversion, bloody discharge.
4. Lymphadenopathy: Palpable axillary, infraclavicular, or supraclavicular nodes.
5. Age > 50 years + unilateral, non-tender mass.
6. High-risk patient: Klinefelter syndrome (19.2-fold risk), BRCA2 mutation (80-fold risk), family history.

Management if red flags present: Urgent referral to breast surgery (2-week wait pathway). Mammography + breast ultrasound + core needle biopsy. Do NOT delay biopsy if clinical suspicion is high.

Q3: Name five drugs that cause gynaecomastia and explain the mechanism for two of them.

Model Answer:

Five drugs:

1. Spironolactone (10% incidence in heart failure trials).
2. Digoxin.
3. Finasteride/Dutasteride (5α-reductase inhibitors).
4. Cimetidine (H2-receptor antagonist).
5. Metoclopramide/Domperidone (dopamine antagonists).

Mechanisms (choose two):

• Spironolactone: Aldosterone antagonist used in heart failure and hypertension. Has anti-androgen effect: (1) Blocks androgen receptors in breast tissue; (2) Inhibits testosterone synthesis. This reduces androgen effect and allows unopposed oestrogen action → gynaecomastia. Dose-dependent (higher doses → higher risk). Alternative: eplerenone (selective mineralocorticoid receptor antagonist, no anti-androgen effect, does NOT cause gynaecomastia).
• Finasteride/Dutasteride: 5α-reductase inhibitors used for benign prostatic hyperplasia (BPH) and male pattern baldness. Mechanism: Inhibit conversion of testosterone to dihydrotestosterone (DHT). DHT has higher affinity for androgen receptors than testosterone. Reducing DHT → decreased androgen effect at breast tissue → relative oestrogen excess → gynaecomastia.

Q4: What is Klinefelter syndrome and why is it relevant to gynaecomastia?

Model Answer:

Klinefelter syndrome:

• Genetic disorder: 47,XXY karyotype (extra X chromosome). Incidence: 1 in 500-1000 males.
• Clinical features:
  • Small, firm testes (less than 5 mL volume, normal 15-25 mL).
  • "Tall stature, eunuchoid proportions (arm span > height, reduced upper:lower segment ratio)."
  • Gynaecomastia (present in ~80%).
  • Reduced facial/body hair (hypogonadism).
  • Infertility (azoospermia or severe oligospermia).
  • Variable learning difficulties.
• Hormonal profile: Primary hypogonadism → High LH, High FSH, Low testosterone.
• Pathophysiology of gynaecomastia in Klinefelter syndrome:
  • Low testosterone (testicular failure).
  • Increased peripheral aromatisation of androgens → increased oestrogen.
  • Increased SHBG → reduced free testosterone → relative oestrogen excess.

Relevance:

1. Most common genetic cause of primary hypogonadism and gynaecomastia.
2. Significantly increased risk of male breast cancer: 19.2-fold increased incidence, 57.8-fold increased mortality compared to general male population. Risk still ~70% lower than in females. Highest risk in 47,XXY mosaics.
3. Management:
   • Testosterone Replacement Therapy (TRT) (lifelong): Improves virilisation, bone density, muscle mass. However, gynaecomastia often persists despite TRT (long-standing, fibrotic).
   • Surgery (subcutaneous mastectomy) if gynaecomastia is cosmetically distressing.
   • Surveillance for breast cancer: Annual clinical breast examination. Low threshold for breast imaging if any breast lump detected.

Q5: What is the first-line medical treatment for symptomatic gynaecomastia and when is it most effective?

Model Answer:

First-line medical treatment: Tamoxifen (selective oestrogen receptor modulator, SERM).

Dosing:

• 10-20 mg once daily for 3-6 months. Can extend to 9-12 months if partial response.

Mechanism:

• Tamoxifen is an oestrogen receptor antagonist in breast tissue. It blocks oestrogen-induced ductal proliferation and stromal hypertrophy.

Efficacy:

• Most effective in early/active-phase gynaecomastia (less than 12 months duration):
  • "Complete resolution: 60-80%."
  • "Partial response (> 50% reduction): 20-40%."
  • "Reduction in breast pain: 80-90%."
• Reduced efficacy in intermediate-phase (12-24 months):
  • "Complete resolution: 20-30%."
• Minimal efficacy in fibrotic phase (> 24 months):
  • "Complete resolution: less than 10%. No response: 70-80%."

Timing matters: Tamoxifen works best in the florid/active phase when tissue is proliferative and oedematous. Once tissue becomes dense and fibrotic (> 2 years), medical therapy is unlikely to work—surgery is the treatment of choice.

Side effects: Generally well-tolerated. Nausea (5-10%), headache (5%), hot flushes (rare in males). Theoretical VTE risk (low in healthy young males).

Off-label use: Tamoxifen is not licensed for gynaecomastia in most countries. Use requires informed consent. Particularly important in adolescents (discuss with patient and parents).

Alternatives: Raloxifene (alternative SERM, similar efficacy), Aromatase inhibitors (anastrozole, letrozole—less evidence, concerns re: growth plate effects in adolescents).

Q6: When is surgery indicated for gynaecomastia and what is the surgical procedure?

Model Answer:

Indications for surgery:

1. Long-standing, fibrotic gynaecomastia (> 2 years duration)—unlikely to respond to medical therapy.
2. Refractory to medical therapy (tamoxifen trial failed after 6 months).
3. Severe cosmetic or psychological distress (body image issues, social embarrassment, impact on quality of life).
4. Patient preference (definitive treatment).

Surgical procedure:

• Subcutaneous mastectomy:
  • "Incision: Periareolar (around lower half of nipple-areola) or transareolar (across nipple). Small, well-hidden scar."
  • "Technique: Excision of glandular disc and fibrous tissue. Preserve nipple-areola complex and skin. Achieve flat chest contour."
  • "Adjunct liposuction: Often used to remove fatty component (pseudogynaecomastia) and optimise cosmetic result."
• Procedure: Day case or overnight stay. General anaesthesia. Duration: 1-2 hours.

Post-operative care:

• Compression garment for 4-6 weeks (reduce haematoma, seroma, optimise contour).
• Avoid strenuous exercise for 6 weeks.
• Histology: Confirm gynaecomastia, exclude malignancy.

Outcomes:

• > 95% patient satisfaction.
• Low recurrence rate (less than 5%) if adequate excision.
• Complications (rare): Haematoma (2-5%), seroma (5%), infection (less than 2%), nipple necrosis (rare less than 1%), asymmetry (5-10%, may require revision).
• Significant improvement in quality of life, body image, self-esteem, especially in adolescents.

Surgery is the ONLY definitive treatment for fibrotic gynaecomastia. Early surgery (after 2 years of observation or failed medical therapy) can significantly improve quality of life in young males with severe psychological distress.

Examination Pearls (MRCP/MRCS Clinical Stations)

1. Always examine the testes when assessing gynaecomastia. Look for: testicular volume (hypogonadism if less than 15 mL), testicular mass (tumour), asymmetry.

2. Palpation technique for distinguishing gynaecomastia vs pseudogynaecomastia: Patient supine, fingers flat, move towards nipple. Concentric rubbery disc = gynaecomastia. Soft diffuse fat = pseudogynaecomastia.

3. Think "Drug History": 10-25% of gynaecomastia is drug-induced. Always ask about: spironolactone, digoxin, finasteride, cimetidine, PPIs, metoclopramide, antipsychotics, cannabis, anabolic steroids, alcohol.

4. Red Flag Triad for Male Breast Cancer: (1) Hard, eccentric, fixed mass. (2) Skin/nipple changes. (3) Lymphadenopathy. Any ONE → urgent referral.

5. Klinefelter syndrome: Small firm testes + tall stature + gynaecomastia + infertility. 19.2-fold increased breast cancer risk. High LH, high FSH, low testosterone. Karyotype: 47,XXY.

6. Tamoxifen works best early (less than 12 months). Surgery is definitive for fibrotic gynaecomastia (> 2 years).

7. Pubertal gynaecomastia (60% of boys aged 10-16): Reassurance + observation. > 90% resolve within 2 years. No investigations unless atypical (prepubertal, unilateral, hard, rapid progression, testicular abnormality).

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Medical Disclaimer: MedVellum content is for educational purposes and clinical reference. Clinical decisions should account for individual patient circumstances. Always consult appropriate specialists and follow local guidelines.