Breast Enlargement in Men

Swelling of the breast tissue in a male is an embarrassing symptom, often presented behind the facade of a ‘calling card’. The following differential diagnosis does not include other causes of breast swelling, which are referred to in the Top Tips at the end of this section. In true breast swelling, glandular tissue is palpable behind the areola and is usually bilateral.

Published: 2nd August 2022 | Updated: 15th August 2022

Differential diagnosis

Common Diagnoses

  • Puberty
  • Drugs (Spironolactone, Cimetidine, Digoxin, Cyproterone, Finasteride, Marijuana)
  • Chronic Liver Disease (Especially Alcohol)
  • Lung Carcinoma
  • Hyperthyroidism

Occasional Diagnoses

  • Hypothyroidism
  • 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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Website disclaimer

Pulse Reference is based on the best-selling book Symptom Sorter.

The experts behind Pulse Reference are Dr Keith Hopcroft who is the co-author of Symptom Sorter, a GP in Essex and Pulse’s editorial advisor and Dr Poppy Freeman, a GP in Camden and also a clinical advisor to Pulse.

This website is for clinical guidance only and cannot give definitive diagnostic information. Practitioners should work within the limits of their individual professional practice, seek guidance when necessary and refer appropriately.