Gynaecomastia

Benign proliferation of the glandular tissue of the male breast.

Aetiology

Most commonly:
- Physiological high serum oestradiol to testosterone (25%)
  - Neonates
  - Puberty
  - Elderly
- Drugs (20%)
  - Spironolactone
  - Recreational including THC
  - Oestrogens
  - Etc.
- No detectable abnormality (25%)
- Increased oestrogens: (10%)
  - Cirrhosis/malnutrition
  - Testicular tumours
  - Hyperthyroidism
- Decreased androgens: (10%)
  - Hypogonadism
  - CKD
Drugs (most commonly things that affect androgen/oestrogen synthesis)
- Antiandrogens/inhibitors of androgen synthesis
- Antibiotics
- Antiulcer drugs
- Cancer chemotherapeutic drugs
- Cardiovascular drugs
  - ACE inhibitors
  - Amiodarone
  - CCBs
  - Digoxin
  - Methyldopa
  - Reserpine
  - Statins
  - Spironolactone
- Drugs of abuse
  - Alcohol
  - Amphetamines
  - Heroin
  - THC
  - Methadone
- Hormones
  - Androgens
  - Anabolic steroids
  - Chorionic gonadotropin
  - Oestrogens
  - Growth hormone
- Psychoactive drugs
  - Diazepam
  - Haloperidol
  - Phenothiazines
  - Tricyclic antidepressants
  - Atypical antipsychotics
- Other
  - Domperidone

Pubertal hypertrophy
- Unilateral or bilateral
- Can be painful and tender
- Tends to regress with adulthood
Senescent hypertrophy
- Men >50yo
- Usually asymptomatic
- Frequently unilateral

Definition: palpable breast tissue extending outside the area under the nipple, or recent growth and heaviness.
Smooth, firm, saucer-shaped
Four typical features:
- Glandular tissue centrally located
- Symmetrical in shape
- Usually bilateral
- Tender to palpation during early or growth phase

Imaging not usually recommended
- Consider mammography if unilateral and some doubt
- Mammogram - 'fan-shaped density emanating from the nipple, gradually blending into surrounding fat'
- USS if discrete lump identified
Investigate for common causes
- FBE, UEC, TSH as standard
- If no obvious cause: hCG, LH, FSH, testosterone, oestradiol, AFP, prolactin
  - If elevated hCG plus suppressed LH - likely testicular or extragonadal germ cell tumour
  - High oestradiol + low LH suggests testicular tumour (Leydig or Sertoli)
- Reasonable to do morning serum total testosterone concentration in older men
Histology
- Glandular changes are the same regardless of aetiology
- Extent of glandular proliferation depends on intensity and duration of the growth stimulation
- Early - extensive ductal epithelial hyperplasia, increase in stromal and periductal connective tissue, and proliferation of the periductal inflammatory cells
- Late, after 12 or more months: more fibrosis

Made on physical examination - concentric, rubbery-to-firm disk of tissue, often mobile, located directly beneath the areolar area
Differential:
- Pseudogynaecomastia - which is due to an increase in breast fat, not glandular tissue - diffuse breast enlargement without any subareolar glandular tissue. Fingers won't meet any resistance until they reach the nipple.
- Breast cancer - usually can be distinguished on examination. Typically unilateral, non-tender, often fixed masses found eccentric to the nipple-areolar complex.

Fix cause
In adolescents - almost always pubertal gynaecomastia, which resolves spontaneously in most cases. Observation without surgery. Consider surgery if there is unilateral enlargement, it fails to regress, or is cosmetically unacceptable.
Medical treatment
- Companion recommends tamoxifen 10mg daily for up to 6 months
Surgery
- High risk of poor cosmesis, seroma, numb nipple, nipple necrosis
- Liposuction has been done in this setting