There are many causes for lumps in the breast. These range from normal changes in your body to abnormal breast disease. Breast lumps are either benign (noncancerous) or malignant (cancerous).

See also: Breast lumps and cancer

Some lumps are age-dependent. Newborn boys and girls both have lumps of enlarged breast tissue beneath the nipple, which have been stimulated by the mother's hormones. These disappear within a few months of birth.

Beginning as early as age 8, girls may develop tender lumps beneath one or both nipples (frequently only one). These lumps are breast buds and are one of the earlier signs of the beginning of puberty.

Boys at mid-puberty (usually around age 14 or 15) may develop tender lumps beneath one or both nipples, also in response to the hormonal changes of puberty. These tend to disappear over a period of 6 months to 1 year. See: Gynecomastia

It is also important to remember that hormonal changes just prior to menstruation may give a lumpy or granular feeling to the breast tissue.

The discovery of a lump in the breast usually brings the thought of breast cancer immediately to mind. Breast cancer may occur in men and women, but it is much more common in women. For specific information, see the article on breast cancer.

However, it is important to remember that 80-85% of all breast lumps are benign, especially in women under age 40. Benign causes of breast lumps include:

• Breast infection (breast abscess)
• Fibrocystic breast disease
• Fibroadenoma
• Fat necrosis (damage to some of the fat tissue within the breast; a fat necrosis mass cannot be distinguished from breast cancer without biopsy)

Symptoms depend on the underlying cause of the lump. Signs of a potentially cancerous breast lump may include:

• A painless lump that is firm or hard, with irregular borders (edges)
• Armpit lump
• Arm swelling
• Bone pain
• Difference in breast size, compared with what it previously looked like
• Nipple changes, including pulling inward, swelling, or itching
• Nipple discharge -- usually bloody or straw-colored fluid
• Skin changes such as dimpling or "orange peel" appearance, redness, easy to see veins on breast surface, and eventually skin ulceration
• Weight loss

The doctor will perform a breast exam to feel for lumps. Tests that may be used to determine if a lump is cancer may include:

• Breast biopsy
• Breast ultrasound
• Mammogram
• Needle aspiration

Treatment depends on the underlying cause of the breast lump.For specific treatment information, see the article on the specific disease.

The long-term outlook depends on the type of problem. See the specific condition for detailed information.

Call your health care provider if you find a new, unusual, or changing lump during your breast self-examination.

Also call for an appointment if you are a woman:

• 40 or older who has never had a baseline mammogram
• 35 or older with a mother or sister who have had breast cancer, or a personal history of breast, uterine, ovarian, or colon cancer
• 25 or older, and you are not sure how to perform a breast self-examination

To avoid fibrocystic changes in your breast tissue, avoid excessive fat and caffeine in your diet.

Most cases of breast cancer cannot be prevented. However, early detection and prompt treatment is important. All women over the age of 40 should perform breast self-exam monthly, preferably at the end of their menstrual period when the breasts are less tender. Women who are breastfeeding should examine their breasts after completing a feeding. Also get routine breast exams from your doctor and routine mammograms.

Saslow D, Hannan J, Osuch J, et al. Clinical breast examination: practical recommendations for optimizing performance and reporting. CA Cancer J Clin. 2004; 54:327-344.