Overview of gynecomastia in the modern era and the Leeds Gynaecomastia Investigation algorithm.

Gynecomastia is a benign enlargement of male breast glandular tissue. At least a third of males are affected at some time during their lifetime. Idiopathic causes exceed other etiologies and relate to an imbalance in the ratio of estrogen to androgen tissue levels or end-organ responsiveness to these hormones. Assessment must include a thorough history and clinical examination, specific blood investigations and usually tissue sampling and/or breast imaging. Management consists of a combination of measures that may include simple reassurance, pharmacological manipulation, medical treatment or surgery. Hormone therapy may help to abort the acute proliferative phase of gynecomastia with a 30% response rate but should not be considered in chronic established cases. Surgical treatment may comprise simple liposuction for a predominant fatty component or direct excision when glandular tissue is predominant. The main aim is to control the patient's symptoms and to exclude other etiological factors.