[Phenotype of patients with gynecomastia]

Gynecomastia, a benign enlargement of the breast glandular tissue in men. The aim of the study was to evaluate the phenotype of patients with gynecomastia, in particular antropometric assessment, breast ultrasound examination and hormonal testing, as well as to estimate possible causes of gynecomastia in studied population.

Two hundred-twenty men were enrolled in the study: 126 patients with gynecomastia and 94 healthy volunteers as a control group. Detailed medical examination, breast ultrasound and hormonal assays for T, E2, LH, FSH, SHBG, S-DHEA, PRL and TSH were performed. Calculation of free testosterone concentration was done.

The results of clinical and hormonal evaluation enabled to divide the cases into three groups: patients with idiopathic gynecomastia (58 subjects, 46%), with hypogonadism (34 subjects, 27%) and drug-induced or associated with other disorders gynecomastia (34 subjects, 27%). We found that men with gynecomastia, particularly associated with hypogonadism, had significantly higher BMI compared with control group. Ultrasound examination revealed the positive correlation between breast tissue volume and BMI, duration of gynecomastia and estradiol level, while negative correlation with testosterone level. We demonstrated significant differences in LH, T, SHBG, fT and S-DHEA levels between cases and controls. There were no differences in PRL, FSH and TSH levels among groups. Significant elevation of SHBG concentration in all groups of patients, including idiopathic gynecomastia cases, compared with controls, was remarkable.

Clinical evaluation and hormonal profile can help to classify patient with gynecomastia into one of three groups: idiopathic gynecomastia, associated with hypogonadism, and drug-induced or associated with other diseases. Idiopathic gynecomastia - of unknown etiology is diagnosed in almost half of all cases (46%). We showed that apart from well known hormonal disturbances leading to gynecomastia, like hypogonadism or hyperestrogenism, also subtle hormonal alterations, such as sex hormone binding globuline (SHBG) level elevation may contribute to breast enlargement.