Breast Enlargement in Men

Differential Diagnosis

Common Diagnoses

Occasional Diagnoses

  • Hyperprolactinaemia
  • Haemodialysis and Chronic Renal Failure
  • Testicular Carcinoma
  • Adrenal Carcinoma
  • Cryptorchidism and other Causes of Hypogonadism

Rare Diagnoses

  • Klinefelter’s Syndrome
  • True Hermaphroditism and Male Pseudohermaphroditism
  • Acromegaly
  • Mccune–Albright Syndrome
  • Hypernephroma
  • Carcinoma

Ready Reckoner

Key distinguishing features of the most common diagnoses

PubertyDrugsLiver DiseaseLung CancerHyperthyroidism
Often UnilateralYesNoNoNoNo
Weight LossNoNoPossibleYesYes
Generally UnwellNoPossibleYesYesYes
Other Physical SignsNoPossibleYesYesPossible

Possible Investigations

Likely:FBC, U&E, LFT, TFT.

Possible:Testosterone, CXR, tests of pituitary function

Small Print:Tumour markers, chromosome analysis, CT scan, biopsy

  • FBC: Many chronic systemic illnesses can cause gynaecomastia. There may be an associated normochromic, normocytic anaemia. MCV may be raised in hypothyroidism and chronic liver disease.
  • U&E and LFT: Will reveal chronic renal and liver disease.
  • TFT: To diagnose thyroid abnormality.
  • Testosterone: Reduced in hypogonadism and chronic illness including liver disease.
  • CXR: If lung carcinoma a possibility.
  • Tests of pituitary function (e.g. FSH, LH, prolactin and other more complex, hospital-based tests): To check for pituitary hormone abnormalities.
  • Tumour markers (usually hospital-based): AFP and HCG act as tumour markers for testicular carcinoma.
  • Chromosome analysis: For Klinefelter’s syndrome.
  • CT scan (secondary care): May be necessary for testicular tumour staging and diagnosis of adrenal and renal tumours.
  • Biopsy: If carcinoma suspected.

Top Tips

  • Many male breast swellings are not true breast enlargement – possibilities include simple obesity, abscess, sebaceous cyst and lipoma.
  • Pubertal boys will be very self-conscious about gynaecomastia. Reassure them that the problem is common and will resolve, and that they are not changing sex.
  • Iatrogenic causes are common – check the drug history (including over-the-counter and illicit drugs).

Red Flags

  • In a pubertal boy with a ‘normal’ and a ‘small’ testis, the ‘normal’ one may conceal a tumour. Check with an ultrasound if in doubt.
  • Apparent unilateral gynaecomastia in an adult male may be due to breast carcinoma – refer urgently if there is a hard mass, you cannot feel glandular tissue behind the areola or you’re in any doubt.
  • Gynaecomastia with a headache and visual disturbance may be caused by a pituitary tumour. Refer urgently.
  • Clubbing of the fingers in a smoker with gynaecomastia is virtually pathognomic of bronchial carcinoma. Investigate urgently.
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