Cysts Breast cysts are fluid-filled collections enclosed by a membrane. They are not related to cancer! The special cells in the membrane lining the cyst are responsible for making the fluid and they can also absorb this fluid. Therefore, a cyst can get larger, stay the same, get smaller or go away by itself. If cysts appear on the mammogram, they can change the way the mammogram looks from year to year.
The cysts in the breast are usually not related to cysts elsewhere in the body (such as on the ovaries or in the skin). If a breast cyst is close to the skin and large enough or hard, it can be felt with our fingers. Often with the ultrasound, we see many more cysts than we are able to feel. Not all the lumps we feel in the breast will be cysts! Breast tissue is normally lumpy, so often we are just feeling normal breast lumpiness when we encounter that "pebbly" texture. The ultrasound is invaluable in telling us what we are feeling.
Breast cysts can appear at any age-in teenagers to ninety-year-olds. We find the most cysts in forty year olds. This implies that cysts are related to the increasing hormone irregularity at this age, but this is not the whole story, as they are still seen in women with no hormonal stimulation. We do see more cysts in postmenopausal women on hormone replacement (estrogen) than in those women who are not taking hormones after menopause. We know of nothing in the diet that affects cyst formation or growth. There is a common misconception that caffeine causes cysts. This is not true! Caffeine may cause breast discomfort, but will not cause cysts.
Often, a woman will notice a sore spot in her breast and start touching that area more carefully. Because breast tissue is normally lumpy, sometimes it will feel like there is a lump in that sore spot. Our patients (and sometimes their doctors) often assume that they have the pain from a cyst in that area. While pain and cysts are often indirectly connected (both can be caused by hormones), the vast majority of cysts do not cause pain and the vast majority of breast pain is not related to cysts! Please refer to the Breast Health Library pamphlet "Breast Pain" for a more complete discussion of this topic.
The ultrasound is the best way to evaluate breast cysts because it is so very sensitive to fluid in the tissues. It tells us if the lumps we feel are cysts or solid or just normal breast tissue. It shows us cysts that are even smaller than 1/8 inch. Only the ultrasound can tell us if a lump we are feeling on physical examination is a cyst or if a nodule we see on the mammogram is a cyst. Ultrasound also has the detail to show us the lining of the cyst and its contents. If these meet our requirements for a simple cyst, it is guaranteed to be unrelated to cancer. If the lining is irregular or there is debris in the cyst, the ultrasound is not sufficient to evaluate the cyst and the fluid needs to be aspirated (drawn out with a needle) to examine the fluid itself under a microscope. Even in this situation, the vast majority of complex cysts will be unrelated to cancer. The debris is usually caused by the lining cells falling off into the fluid and releasing particles and gooey protein contents.
Cyst aspiration is a quick and simple procedure when done with ultrasound guidance. The skin is frequently numbed and a needle is quickly inserted. Suction is applied and the fluid is drawn into a syringe. Most cysts will disappear and never return. Some cysts (less than 25%) will come back, but that does not mean that there is anything wrong with the cyst. Cyst aspiration is done for diagnostic purposes, as described above and also for relief of discomfort and/or anxiety from cysts that can be felt.
Having cysts does not mean that you have "fibrocystic disease". Cysts are so common that almost every woman will have some at some point in her life. It does not mean that she is at a higher risk for developing cancer. Many of our patients need multiple cyst aspirations every year when they visit us, but after a few years the number of cyst aspirations decreases.
