Male gynecomastia has been treated with radiotherapy or surgical resection of the breast gland tissue. The introduction of a new generation of aromatase inhibitors has created an opportunity to treat testosterone-induced gynecomastia with oral medications alone.
Aromatase inhibitors effectively delay epiphysial maturation in boys and improve testosterone levels in adult men. Over the past 15 years it has become evident that in men estradiol is responsible for a number of effects originally attributed to testosterone.
Estradiol has an important role in gaining and maintaining bone mass, closing of the epiphyses and the feedback on gonadotropin secretion. This fact became particularly evident in men with aromatase deficiency. Aromatase is the enzyme responsible for conversion of androgens to estrogens.
Men with estrogen deficiency caused by a mutation in the CYP19 gene suffer from low bone mineral density (BMD) and unfused epiphyses, and have high gonadotropin and testosterone levels. Estrogen excess in turn has been associated with premature closure of the epiphyses, gynecomastia and low gonadotropin and testosterone levels.
Lowering estrogen levels in men has emerged, consequently, as a potential treatment for a number of disorders including pubertas praecox, the andropause (also referred to as late-onset hypogonadism) and
