Section 13. Hormonal Disorders

Chapter 164. Adrenal Gland Disorders

Topics: Introduction | Addison's Disease | Cushing's Syndrome | Virilization | Hyperaldosteronism | Pheochromocytoma

Virilization

Virilization is the development of exaggerated masculine characteristics, usually in women, often as a result of the adrenal glands overproducing androgens (testosterone and similar hormones).

The most common cause of virilization is an enlargement of the hormone-producing portions of the adrenal cortex (adrenal hyperplasia). Sometimes the cause is a small hormone-producing tumor (adenoma or cancer) in the gland. Occasionally, virilization occurs when a cancer outside the adrenal gland produces androgens. Athletes who take large amounts of androgens (anabolic steroids) to increase their muscle bulk may develop symptoms of virilization (see Section 7, Chapter 108). Cystic enlargement of the ovaries may cause virilization, but such cases are almost always mild. Sometimes an abnormality in an enzyme (a protein) in the adrenal glands can also produce virilization.

Symptoms and Diagnosis

Symptoms of virilization include excess facial and body hair (hirsutism), baldness, acne, deepening of the voice, increased muscularity, and an increased sex drive. In women, the uterus shrinks, the clitoris enlarges, the breasts become smaller, and normal menstruation stops.

The combination of body changes makes virilization relatively easy for a doctor to recognize. A test can determine the level of androgens in the blood. If the level is very high, a dexamethasone suppression test can help determine if the problem is coming from the adrenal glands and whether the problem is an adenoma or adrenal hyperplasia. If the problem is adrenal hyperplasia, dexamethasone prevents the adrenal glands from producing androgens. If the problem is an adenoma or cancer, dexamethasone reduces androgen production only partially or not at all. The doctor may also order a computed tomography (CT) or magnetic resonance imaging (MRI) scan to obtain a view of the adrenal glands. In women with cystic ovaries, the testosterone level may appear to be normal, but its binding protein is low so that the free (unbound) fraction is relatively high.

Treatment

Androgen-producing adenomas and adrenal cancers are usually treated by surgically removing the adrenal gland that contains the tumor. For adrenal hyperplasia, small amounts of corticosteroids, such as dexamethasone, generally reduce the production of androgens. The mild virilization caused by cystic ovaries may need no treatment. It can be treated with drugs that lower the free testosterone levels, such as oral contraceptives, or that block the effects of testosterone.