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 hormone-producing tumor (adenoma or cancer) in the gland. Occasionally, virilization occurs when a cancer outside the adrenal gland produces androgens. This cancer is likely to be a tumor of the ovaries, although occasionally overactivity of androgen secretion by the ovaries may occur in later life. Athletes who take large amounts of androgens (anabolic steroids—see Other Drugs of Abuse) to increase their muscle bulk may develop symptoms of virilization. Enlargement of the ovaries due to certain types of cysts may cause virilization, but such cases are almost always mild. Sometimes, a congenital abnormality in an enzyme (a protein) in the adrenal glands can also cause virilization. Such an abnormality is often diagnosed in childhood or adolescence and is termed congenital adrenal hyperplasia.
Symptoms depend on the sex and age of the person affected.
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.
In men, the excess adrenal hormones may suppress gonadal function and cause infertility.
In female infants with congenital adrenal hyperplasia the genitals may resemble those of infant boys. In children, growth may accelerate. If untreated, the growth plates may close prematurely and short stature may result. Affected boys may experience premature sexual maturation.
The combination of body changes makes virilization relatively easy for doctors 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. Doctors may do computed tomography (CT) or magnetic resonance imaging (MRI) to obtain a view of the adrenal glands.
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 hydrocortisone, generally reduce the production of androgens. The mild virilization caused by cysts in the ovaries may need no treatment. It can be treated with drugs that lower the free testosterone levels, such as oral contraceptives, or drugs that block the effects of testosterone.
Last full review/revision September 2014 by Ashley B. Grossman, MD, FRCP, FMedSci