Clinical_Rounds_in_Endocrinology_Volume_II_-_Pediatric_Endocrinology

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84. What are the causes of gynecomastia?

Gynecomastia occurs as a result of altered testosterone/estradiol ratio in favor

of estradiol, which can be due to estrogen excess, androgen deficiency, or

impaired testosterone action. In addition, various drugs are incriminated as the

cause of gynecomastia. The various causes of gynecomastia are summarized in

the figure given below (Figs. 7.17 and 7.18).

Gynecomastia

Androgen deficiency

Primary hypogonadism

Secondary hypogonadism

Estrogen excess

Exogenous estrogen exposure

Endogenous estrogen excess

Estrogen secreting tumors

Increased aromatase activity

• HCG secreting tumors


• Obesity


• Aging


• Thyrotoxicosis


• Aromatase excess syndrome
  Increased substrate


• Hepatic cirrhosis
  Ill defined


• Puberty

Impaired androgen action

Complete/Partial androgen

insensitivity

Fig. 7.17 Etiology of gynecomastia

Fig. 7.18 A 35-year-old
man with diffuse goiter
and thyrotoxicosis. He had
recent-onset gynecomastia

7 Delayed Puberty