Gynecomastia is a common condition affecting between 40 and 60 percent of all males. Breast development easily happens during adolescence and may have many possible causes. It can appear as a small lump just under the areola (colored skin around the nipple). During growth, this mass can be tender.

Gynecomastia has been divided into four types: Type I: (pubertal or benign adolescent breast hypertrophy) refers to the common entity seen in pubertal males. Incidence may be as high as 60-70 percent. It is typically a firm, tender, subareolar mass anywhere from 1-5 cm in diameter. The pubertal adolescent frequently complains of pain in the breasts, particularly when wearing binding clothing. It usually spontaneously resolves within 2 years.

Type II (physiological gynecomastia without evidence of underlying disease, or with evidence of organic disease including the effects of specific drugs) refers to a generalized, nonpainful breast enlargement. It is essential to differentiate between physiologic gynecomastia and breast enlargement due either to a pathologic process or to the use of a specific drug. Careful history taking regarding the time of onset, family history, duration of enlargement, history of systemic illness, weight change, and drug or medication use, is important. Physical examination should include height, weight, blood pressure, breast size, and Tanner staging of both breasts and genitals, in addition to a neurologic assessment.

Type III gynecomastia is general obesity simulating gynecomastia, and Type IV is pectoral muscle hypertrophy.

Common causes of type II gynecomastiaI. Idiopathic
II. Familial causes

a. Associated with anosmia and testicular hypertrophy.
b. Reifenstein's syndrome (male pseudohermaphroditism 2ry to partial androgen insensitivity)
c. Associated with hypogonadism and small penis

III. Specific illnesses or syndromes a. Kleinfelter
b. Male pseudohermaphroditism
c. Testicular feminization syndrome
d. Tumors
e. Leukemia
f. Hemophilia
g. Leprosy
h. Chronic glomerulonephritis

IV. Miscellaneous drugs a. amphetamines
b. anabolic steroids
c. birth control pills
d. cimetidine
e. diazepam
f. corticosteroids
g. digitalis
h. estrogens
j. human chorionic gonadotropin
k. insulin
l. isoniazid and other TB drugs
m. ketoconazole
n. marijuana
o. methadone and other narcotics
p. reserpine
q. tricyclic antidepressants

Gynecomastia is usually secondary to the normal hormonal imbalances between testosterone and estrogen that commonly occurs during puberty (pubertal gynecomastia) and it may affect up to 40 percent of adolescent boys during puberty, usually by the age of 14. In these children, the breast tissue is usually less than 4 centimeters in diameter and will disappear without treatment in two years in 75 percent of children and within 3 years in 90 percent of children. Although usually normal, your child with gynecomastia should still have an evaluation with your Pediatrician. You and your Pediatrician should reassure your teenager that this is normal and in most cases should disappear within a few months or years without treatment.

Sometimes, treatment may be required if he has very large breast development, if it is not regressing, or if it is causing a lot of stress or anxiety in your child. Male breast growth that has not stopped by three years, may not go away. In these situations, an evaluation by an experienced Plastic Surgeon can be helpful, either to provide further reassurance or to surgically remove the breast tissue. Surgical sculpture in skilled hands can be a simple solution for this problem.

Gynecomastia can also be a side effect of some medications and drugs. The most common medication that causes breast development is estrogen, and its effects can be seen in a child who ingests estrogen pills, or even if a family member is using an estrogen cream and has prolonged contact with him. Other medications can include certain antidepressants, drugs used to treat high blood pressure and tuberculosis, and some chemotherapy agents. Street drugs that may cause gynecomastia include marijuana, heroin and alcohol. Anabolic steroids can also stimulate male breast growth.

There are also some diseases that can cause gynecomastia, including certain endocrine disorders, tumors and chronic diseases. Klinefelter's Syndrome is one such problem where there is an extra chromosome that can impair testosterone production and development of male characteristics. Early recognition and appropriate treatment can be very important.

You should also see your Pediatrician if your child has breast development, but has not started puberty yet, or if it occurs before he is nine years old. However, if your child is otherwise growing and developing normally, has started puberty and now has gynecomastia, then he is very likely to just have pubertal gynecomastia and no further evaluation or treatment will be necessary after you see your Pediatrician.