The etiology of gynecomastia remains unclear. Most cases of gynecomastia are thought to result from an imbalance between estrogens and androgens.
1,
11 However, in pubertal gynecomastia, the majority of adolescents have normal estrogen levels, although several studies have demonstrated elevated levels in some patients.
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14 Pubertal gynecomastia is thought to be a physiological phenomenon, and is most commonly seen in midpuberty with Tanner stage 3–4 pubic hair and testicular volumes of 5 to 10 mL bilaterally.
3 In a 3-year longitudinal study of hormonal changes during puberty, study participants with and without gynecomastia were compared.
15 No association was found with race, and no significant difference was found in serum estradiol, testosterone, estrogen/testosterone ratio, or dehydroepiandrosterone-sulfate levels.
15