Many breast lumps turn out to be caused by fibrosis and/or cysts, which are non-cancerous (benign) changes in breast tissue that happen in many women at some time in their lives. These changes are sometimes called fibrocystic changes, and used to be called fibrocystic disease.
Fibrosis and/or cysts are most common in women of child-bearing age, but they can affect women of any age. They may be found in different parts of the breast and in both breasts at the same time.
Fibrosis refers to a large amount of fibrous tissue, the same tissue that ligaments and scar tissue are made of. Areas of fibrosis feel rubbery, firm, or hard to the touch.
A round, movable lump, which might also be tender to the touch, suggests a cyst. Cysts are fluid-filled, round or oval sacs within the breasts. They are most often found in women in their 40s, but they can occur in women of any age. Monthly hormone changes often cause cysts to get bigger and become painful and sometimes more noticeable just before the menstrual period.
Cysts begin when fluid starts to build up inside the breast glands. Microcysts (tiny, microscopic cysts) are too small to feel and are found only when tissue is looked at under a microscope. If fluid continues to build up, macrocysts (large cysts) can form. These can be felt easily and can be as large as 1 or 2 inches across.
Most often, fibrocystic changes are diagnosed based on symptoms, such as breast lumps, swelling, and/or tenderness or pain. These symptoms tend to be worse just before your menstrual period begins, and may change as you move through different stages of your menstrual cycle. Your breasts may feel lumpy and, sometimes, you may notice a clear or slightly cloudy nipple discharge.
Sometimes, one of the lumps might feel firmer or have other features that lead to a concern about cancer. When this happens, an ultrasound may be done to see if the lump is solid or is just filled with fluid (called a simple cyst). If the ultrasound shows the lump is solid or if the cyst has both fluid and solid components (a complex cyst), a biopsy may be needed to make sure that it’s not cancer.
How do fibrosis and simple cysts affect your risk for breast cancer?
Neither fibrosis nor simple cysts increase your risk of later developing breast cancer. Complex cysts are more of a concern, as there is a small chance they might contain cancer or put you at risk of cancer later on, depending on what is found at the time of biopsy.
Cyst fluid doesn’t need to be removed unless it’s causing discomfort. But it can be drained by putting a thin, hollow needle into the cyst, which might be done to confirm the diagnosis. Removing the fluid may reduce pressure and pain for some time. If removed, the fluid might come back later, but cysts may also go away over time. For cysts that continue to come back and cause symptoms, surgery to remove them might be an option.
Most women with fibrocystic changes and without bothersome symptoms do not need treatment, but they might be watched closely. If you have mild discomfort from fibrosis, you may get relief from well-fitted, supportive bras, applying heat, or using over-the-counter pain relievers.
Some women report that their breast symptoms improve if they avoid caffeine and other stimulants found in coffee, tea, chocolate, and many soft drinks. Studies have not found that these stimulants cause these symptoms, but many women feel that avoiding these foods and drinks for a couple of months is worth trying.
Because breast swelling toward the end of the menstrual cycle is painful for some women, some doctors recommend pain relievers such as acetaminophen or ibuprofen, or other medicines. It’s been suggested that some types of vitamin or herbal supplements might relieve symptoms, but so far none have been proven to be helpful, and some may have side effects if taken in large doses. Some doctors prescribe hormones, such as oral contraceptives (birth control pills), tamoxifen, or androgens. But these are usually given only to women with severe symptoms because they also can have serious side effects.