Gynaecomastia

Question 1

Gynaecomastia - Causes

Answer 1

Gynaecomastia

Gynaecomastia describes an abnormal amount of breast tissue in males and is usually caused by an increased oestrogen:androgen ratio. It is important to differentiate the causes of galactorrhoea (due to the actions of prolactin on breast tissue) from those of gynaecomastia

Causes of gynaecomastia
•physiological: normal in puberty
•syndromes with androgen deficiency: Kallman's, Klinefelter's
•testicular failure: e.g. mumps
•liver disease
•testicular cancer e.g. seminoma secreting hCG
•ectopic tumour secretion
•hyperthyroidism
•haemodialysis
•drugs: see below

Drug causes of gynaecomastia
•spironolactone (most common drug cause)
•cimetidine
•digoxin
•cannabis
•finasteride
•gonadorelin analogues e.g. Goserelin, buserelin
•oestrogens, anabolic steroids

Very rare drug causes of gynaecomastia
•tricyclics 
•isoniazid
•calcium channel blockers
•heroin
•busulfan
•methyldopa

Question 2

Gynaecomastia - Example Questions

Answer 2

A 55 year-old male presents to endocrine outpatient clinic for investigation of gynaecomastia. On examination he has bilateral growth of breast tissue with palpable glandular tissue around the areolae. His past medical history includes hypertension, hypothyroidism, and congestive cardiac failure. He drinks 30 units of alcohol per week. His regular medications include: levothyroxine, amlodipine, bisoprolol, lisinopril and spironolactone.

On examination he is of normal stature, there are no peripheral stigmata of chronic liver disease or testicular masses.

What is the most likely explanation of his gynaecomastia?

 Cirrhosis 
 Hypopituitarism 
>  Iatrogenic 
 Klinefelter's syndrome 
 Idiopathic 

The most likely explanation for this gentlemans gynaecomastia given the negative examination findings is a side effect of his current regular medications. There are many drugs that can cause gynaecomastia; in this cause the culprit could be either amlodipine or spironolactone