January 7, 2011

Dear Mayo Clinic:

I am a 40-year-old male recently diagnosed with gynecomastia. Am I at greater risk for breast cancer?

Answer:

Gynecomastia — enlarged male breast tissue — may slightly increase your risk of breast cancer. But even with gynecomastia, your risk of developing male breast cancer is very small. In most cases, gynecomastia resolves on its own with minimal treatment and little risk of long-term complications.

Gynecomastia is a noncancerous excess of male breast gland tissue. It more commonly involves both breasts but can occur in only one breast. Most often, the condition is caused by hormone changes. Men normally have much higher levels of testosterone (a male hormone) than estrogen (a female hormone). Gynecomastia is usually triggered by an imbalance in levels of testosterone to estrogen. The condition affects 35 to 40 percent of healthy men at some time in their life and is often seen in newborn male babies, adolescent boys around the time of puberty, and in older men.

The hormone changes that cause gynecomastia are usually just a natural part of the aging process, but certain medications and underlying health conditions can also be factors. For example, some medications used for ulcers, heart conditions, benign prostate problems and prostate cancer can cause gynecomastia. Health conditions such as testicular tumors, testicular failure, obesity, pituitary gland disorders and cirrhosis of the liver can also result in the condition. Gynecomastia has also been associated with illicit drug use, alcohol use, and herbal supplements that contain phytoestrogen.

Having gynecomastia may slightly increase your risk of male breast cancer due to the change in ratio of estrogen to testosterone in your body. Other risk factors for male breast cancer include a strong family history of breast cancer, Jewish ancestry, a family history of a breast cancer gene mutation and other genetic disorders.

Although gynecomastia is common, male breast cancer is rare. In the United States, only about 2,000 cases of male breast cancer are diagnosed annually, and about 400 men die of breast cancer each year.

That said, it's still a good idea to do periodic self-examinations to check for any new lumps or changes and to follow your recommended checkup schedule with your health care provider. All men — with or without a diagnosis of gynecomastia — should be evaluated promptly if a breast lump or change is noted on their exam. The evaluation typically involves a medical history review, a physical exam and, in some cases, a diagnostic mammogram and/or ultrasound to further evaluate the lump. A breast biopsy may be performed to identify the cause of the lump.

In addition to gynecomastia or breast cancer, male breast lumps may be caused by fatty tumors, cysts or blood collection. Another condition, pseudo-gynecomastia, may be the reason for a breast change or lump. It has nothing to do with the breast tissue. Rather, pseudo-gynecomastia is simply an enlargement of tissue underneath the nipple on the chest wall due to fat accumulation.

Typically, gynecomastia is not permanent. It usually progresses through several phases and then goes away. First, there's an inflammatory phase in which most men experience some breast tenderness. After about six to 12 months, the inflammation subsides, leaving only scar tissue behind. In most cases, little or no treatment is needed.

If gynecomastia is caused by an underlying medical condition, such as a pituitary gland disorder or a liver condition known as cirrhosis, that condition may need treatment. If you're taking medications that can cause gynecomastia, your doctor may recommend stopping them or substituting another medication.

If the excess breast tissue is persistent and associated with pain or discomfort, treatment may include a short course of an estrogen-blocking agent commonly used in the treatment of breast cancer, such as tamoxifen. If significant symptomatic breast enlargement continues despite other treatment, surgery may be an option to remove the excess breast gland tissue.

If you have questions or concerns about gynecomastia, or if you have other risk factors for male breast cancer, talk to your doctor to ensure that your treatment plan and follow-up schedule are appropriate to your needs.

— Lonzetta Neal, M.D., and Sandhya Pruthi, M.D., Breast Dia

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