FAQS: Fibrocystic Breasts (Fibrocystic Changes) and Fibroadenomas

Worried about a lump in your breast? Breast lumps can be caused by a number of other factors besides breast cancer. While breast lumps should always be taken seriously, these FAQS may help you determine just how quickly you should get to the doctor.

Q. My breasts were feeling really painful, especially the right one, so I went to the doctor. She said I have “fibrocystic changes,” and it’s nothing to worry about. I’m glad it’s not cancer, but what is it?

A. Fibrocystic changes (FCC), also known as fibrocystic breasts, are the most common benign condition of the breast, occurring in about 50% of women at some point during their lives. Highly influenced by reproductive hormones and the menstrual cycle, FCC is most often found in women under the age of 50. Post-menopausal women rarely experience FCC.

Your breasts are made up of fat; glandular tissue (e.g., milk lobules and milk ducts); and fibrous (stromal) tissue, a connective tissue (akin to scar tissue or ligaments, in consistency) that holds everything together. Sometimes, this fibrous tissue becomes more prominent: this is called fibrosis. Doctors don’t know exactly why this happens, but suspect it’s related to reproductive hormones, particularly estrogen. 

Your breasts may also develop a cyst or numerous cysts, which are round or oval, fluid-filled sacs. These cysts start inside breast glands, and can remain very small, or can become quite large. As cysts grow, they push against breast tissue, which can be painful. About 33% of women between the ages of 35 and 50 experience breast cysts, so they’re fairly common.

Taken together, these two conditions—fibrosis, and cysts—are called fibrocystic breasts or fibrocystic changes. The condition was formerly known as fibrocystic breast disease, but doctors have determined it’s so common, and generally harmless, that it doesn’t qualify as a disease.

Q. Well, I’m glad it’s fairly normal, but it makes it hard to tell if I’m actually feeling a lump during my breast self exam. How can I determine what’s FCC, vs. something to worry about?

A. A cancerous breast tumor usually feels hard; may be round, or irregularly shaped; is fixed in place; and is nearly always painless. A cyst will feel round and smooth; will be very moveable; and is often painful. Fibrosis will feel firm or rubbery to the touch, and may seem “ropy” rather than round. And fibrosis, like a cyst, can hurt.

Another significant difference is that fibrocystic changes are often noticed in both breasts, while breast cancer usually appears in just one. And FCC often evolves during the course of your menstrual cycle, with lumps enlarging and becoming more painful and tender just before and during your period. After your period, lumps may get smaller, or even disappear altogether. A breast cancer tumor doesn’t change over the course of your period.

Still, if you have any doubts at all about a lump you’ve noticed in your breast—it doesn’t change over the course of your period, feels hard rather than soft, and is fixed in place—it’s best to get it checked out. An ultrasound can usually distinguish cysts fairly easily. And if an ultrasound doesn’t reveal cysts, your doctor may recommend an MRI or diagnostic mammogram, followed by a biopsy, if necessary, to determine if the mass is simply fibrosis, or something more serious.