24th May 2025

Gynaecomastia

Gynaecomastia is characterised by the benign proliferation of the glandular tissue of the breast and is frequently seen amongst the adolescent male population, with 2 in every 3 teenagers experiencing some degree of gynaecomastia. Whilst true gynaecomastia is reserved for enlargement of the breast tissue itself, gynaecomastia can also be used to describe breast enlargement secondary to an increase in fatty tissue, sometimes termed pseudo-gynaecomastia.

Clinical examination usually reveals a symmetrical enlargement of breast tissue that is centrally placed and tender upon palpation. Pain is typically associated with an adolescent population and many older men with gynaecomastia may remain asymptomatic. Some patients may only experience a unilateral enlargement of the breast tissue.

The main cause of gynaecomastia in adolescents is almost always puberty related and the majority of cases will resolve spontaneously. However, 1 in 4 will suffer with persistent pubertal gynaecomastia. Drug induced gynaecomastia accounts for around 20% of cases, with a plethora of medications having been implicated, most notably those that affect androgen and/or oestrogen levels. Those with the best evidence include Spironolactone, Cimetidine, Ketoconazole, Gonadotropin-releasing hormone (GnRH) agonists and 5-alpha-reductase inhibitors. Other, less common causes, include liver cirrhosis, hypogonadism, testicular tumours, hyperthyroidism and chronic kidney disease.

Investigating gynaecomastia mandates a thorough history and examination. Signs and symptoms related to the aforementioned disease processes should be evaluated, alongside a detailed medication review. Biochemical testing can be performed and may focus on androgen levels, glucose levels and thyroid function, as well as assessing baseline liver and renal function. Imaging is of little diagnostic use and should be reserved for suspicious cases or those with unilateral breast enlargement. Similarly, histological assessment may be indicated in those with suspicious clinical or radiological findings.

Management is dependent upon the underlying cause. As discussed, the majority of puberty-related gynaecomastia will resolve spontaneously and therefore, no treatment or follow-up is indicated. Drug induced gynaecomastia requires careful consideration of the benefits of the medication versus the unwanted side effect profile. Adapting the dosage, changing or discontinuing the causative medication are all viable options that could be explored. Occasionally, pharmacological management may be suggested, including Tamoxifen and Danazol, whilst surgical intervention is reserved for exceptional circumstances, where prior treatments have failed or quality of life is sufficiently affected. Importantly, gynaecomastia is not associated with an increased risk of breast cancer.