If you find a lump in your breast, don't delay -- see your doctor as soon as possible. Anything you notice that's different from your normal breast tissue should be investigated. The good news is that more than 80 percent of breast lumps turn out to be benign tumors or cysts.
How can my doctor tell whether a lump is cancerous?
If a breast exam, mammogram, or follow-up ultrasound turns up a suspicious mass in your breast, you may want to have a biopsy -- a procedure in which a doctor takes a small tissue sample from the lump and a pathologist looks at it under a microscope. That's the only way to be sure whether a lump is cancerous. There are a number of different biopsies you can get, and each procedure has its pros and cons. An excisional biopsy (removing the whole lump) should be definitive, but it is also a more invasive procedure. A needle or core biopsy (in which fluid or tissue are extracted) may be quick and only needs local anesthesia, but also may require a follow-up biopsy since it more easily misses cancer cells. Afterwards, even if the biopsy is negative, the lump should be followed -- and removed if it grows or changes.
If it's not cancer, what could it be?
In addition to the many kinds of completely harmless breast lumps, there are some that may slightly increase your risk of getting breast cancer in the future and a few that may not be cancer but should be removed anyway. Here's a guide to some of the most common types of breast lumps and what you should do about them.
Most breast lumps are caused by fibrocystic breast changes, also known as benign breast disease or mammary dysplasia. In spite of the intimidating names, this condition is harmless. At least half of all women have it at some point, usually during their childbearing years.
Some of the lumps are solid, and some are fluid-filled cysts. (A cyst may form when one of your milk ducts becomes blocked.) No one knows what causes these changes in the breasts, but estrogen and progesterone, the hormones that control the menstrual cycle, can make lumps or cysts more prominent or painful during the week before your period begins. You may feel one lump or many. Some women say their breasts feel like bags of peas; others don't feel the lumps at all.
These masses usually show up on both mammograms and ultrasound scans. To determine whether a suspicious lump is fibrocystic rather than cancerous, your doctor may need to do a biopsy. If the lump is a cyst, the fluid can be drained with a needle and syringe in the doctor's office. Having fibrocystic changes may slightly increase your risk for getting breast cancer. In rare cases, the cells from a fibrocystic lump show some precancerous changes called atypical hyperplasia, a condition that may increase your chance of developing breast cancer. How big a risk atypical hyperplasia presents depends on a woman's other risk factors -- family history and age of first pregnancy among them. If you have this condition, you may want to talk to your doctor to see if a preventative course of tamoxifen would be appropriate for you. Also discuss with your doctor how often you should have breast exams and mammograms.
Not all women have pain or other symptoms as a result of fibrocystic changes. Some women do find that their symptoms improve when they cut back on caffeine and salt or take diuretics, although studies have found no benefit from this. Some physicians recommend vitamin E or capsules of evening primrose oil. If your symptoms are severe, ask your doctor about the prescription drugs danazol (Danocrine) and bromocriptine (Parlodel), but be aware that they're expensive and can have serious side effects. Particularly bothersome lumps that don't respond to any of these treatments can be surgically removed.
A movable lump that feels like a marble in your breast may be a fibroadenoma. This is a benign mass made up of both connective and glandular tissue (tissue from the milk ducts and glands). Fibroadenomas are most common in women who are in their 20s and 30s. Some are too small to feel; others may be several inches across. Doctors sometimes recommend that you have this kind of lump surgically removed to make sure that it's not cancerous, even if the biopsy was negative. Some studies show that women with fibroadenomas have a slightly increased risk of getting breast cancer later on.
Rarely, a lump may turn out to be a phyllodes tumor. Most often benign, this kind of lump also consists of both connective and glandular tissue, but the connective-tissue cells may have started to grow too fast. Most of the time you'll have the lump removed, along with a roughly one-inch margin of healthy breast tissue. It's important to have a clear margin of normal tissue because, even when they're benign, these tumors have a high rate of local recurrence. In very rare cases, the lump will be malignant, and you may need to have your breast removed.
If you notice a bloody discharge from your nipple, you may have an intraductal papilloma -- usually a small growth in a milk duct behind the nipple. If the lump isn't large enough to be felt, a ductogram may be needed. This is a mammogram that's taken after liquid is injected through the nipple into the milk duct. On the x-ray, the location of the liquid shows whether the duct contains a mass. A papilloma is usually removed, along with a segment of the milk duct. Ductoscopy, a technique for directly visualizing the inside of the duct using tiny scopes, is now used to aid in the diagnosis and treatment of bloody nipple discharge. The technique allows the doctor to see the growth before it's removed so that less of the duct needs to come out with it.
Granular cell tumor
A firm, movable lump measuring half an inch to an inch across may be a granular cell tumor. These masses are very rare and almost always benign, but they should be removed anyway. Having one doesn't make you more likely to get breast cancer.
A lump that develops after you've had surgery, a breast injury, or radiation treatment may be caused by fat necrosis, or scar tissue overlying an area of fatty tissue that has been damaged. Its firmness makes it difficult to distinguish from cancerous lumps by feel. Sometimes, instead of forming scar tissue, the damaged fat cells die and release the fat inside, which collects to form an oil cyst. This can be drained with a needle and syringe.
If a lump is soft and diffuse, it's likely to be a lipoma, a pocket of fat that's become encased in scar tissue. Lipomas are soft and mobile nodules that are usually surrounded by a thin connective tissue capsule. They feel like fatty pillows in the breast. They can be mistaken for cancer if they're particularly firm, but a biopsy will sort things out. Lipomas are quite common and aren't dangerous at all. They don't increase your chances of getting cancer or need to be removed.
American Cancer Society. Benign Breast Conditions: Not All Lumps Are Cancer. http://www.cancer.org/Treatment/UnderstandingYourDiagnosis/ExamsandTestDescriptions/ForWomenFacingaBreastBiopsy/breast-biopsy-benign-breast-conditions
American Cancer Society. What Are Risk Factors for Breast Cancer? http://www.cancer.org/docroot/CRI/content/CRI_2_4_2X_What_are_the_risk_factors_for_breast_cancer_5.asp
American Cancer Society. For Women Facing a Breast Biopsy. http://www.cancer.org/docroot/CRI/content/CRI_2_4_6x_For_Women_Facing_a_Breast_Biopsy.asp#Types_of_biopsy_procedures
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