Clinical and Biochemical Phenotype of Adolescent Males with Gynecomastia

Objective: Gynecomastia is defined as a benign proliferation of male breast glandular tissue. Its prevalence during puberty varies between 50-60% and is also common in neonatal and elderly males. It develops mainly due to the disequilibrium between estrogen and androgen activity in breast tissue, where estradiol (E2) binds to estrogen receptors and stimulates ductal and glandular cells. The aim of this work was to investigate the relationship between sex hormone alterations and the natural history of gynecomastia. Methods: Participants in this study were young males referred to an outpatient clinic, between January 2011 and February 2016, with breast enlargement. Thyroid function, liver function, hormone concentrations and tumor markers were measured and anthropometric assessment was conducted. Results: Subjects comprised 93 males, aged 9 to 18 (mean±standard deviation age 13.8±2.6) years. In 63 of 93 (67.7%) the gynecomastia was confirmed and 28 were followed-up for a median period of three months. None of the boys showed any reduction in breast size during follow-up. There was no correlation between body mass index Z-score and breast size. Breast enlargement progressed in nine boys (32.1%). A positive correlation between estrogen to testosterone (E2/TTE) ratio and Tanner B stage (r=0.47; p=0.034) was observed. Conclusion: The E2/TTE ratio may be a helpful tool in diagnosing gynecomastia. Altered E2/TTE ratio might be responsible for a proportion of cases described previously as idiopathic. Additionally, weight loss does not imply reduction of breast size in boys. Nonetheless it should be the first step in the management of prolonged gynecomastia.