FAQS: Breast Cysts

by PJ Hamel Patient Expert

What is a breast cyst?

A common source of breast lumps is the breast cyst, a benign yet annoying condition experienced by about 1 in 3 pre-menopausal women.A cyst is like an internal blister: a fluid-filled sac. There’s no known cause for cysts, though they’re quite common in younger women; and this leads some researchers to believe that their formation is tied to hormones, particularly estrogen.

A cyst forms when connective tissue and glands in the breast grow too quickly, for some reason; again, this may be hormonal. This overgrowth of tissue can block a milk duct in the breast, causing it to fill with fluid; this fluid-filled duct is called a cyst.

Cysts can be tiny, and disappear on their own; or they may grow as large as a golf ball, become painful, and need to be drained. But cysts aren’t considered dangerous; they don’t signal cancer, nor will a cyst turn into a cancerous tumor.

How to identify a possible cyst

It’s possible, if a woman is unfamiliar with the usual shape and feel of her breasts, that she may notice a lump that seems to have “just appeared,” and that the lump turns out to be cancer. But most lumps that seem to crop up overnight are cysts.

Cysts generally feel squishy to the touch (think water balloon), and moveable, rather than firmly fixed in place. Most cysts feel like a smooth round or oval; though at times they may feel irregularly shaped.

Even if the lump you feel seems hard or firm, however, don’t panic; cysts that form deep within the breast can push the tissue around them out of shape, making normal breast tissue feel like a lump.

Another indication that the lump may be a cyst is pain. Cancerous breast lumps are seldom painful; cysts often are. If you don’t see a doctor right away, and notice during the next several weeks that the lump becomes painful at times (particularly in the days before your period), this is another indication that it’s a cyst, not cancer.

While you can make an educated guess about whether or not that lump you feel is a cyst, only testing can determine for sure.

When to see a doctor

It’s perfectly reasonable to wait a few weeks and see if the lump you’ve felt disappears. If it does, then it was most likely something connected with your menstrual cycle; breast cancer doesn’t come and go in synch with your period.

If the lump doesn’t disappear, then you’ll want to see your doctor.

Diagnosing and treating cysts

The usual first step for any breast lump is a mammogram. However, if the doctor examines the lump and feels there’s a good chance it could be a cyst, s/he may skip the mammogram and perform a fine-needle aspiration: a procedure that draws fluid out of the lump.

This sounds painful; but surprisingly, for most women it’s not. Your skin will be anesthetized, a needle inserted into the lump, and an attempt made to withdraw fluid. If fluid is withdrawn and the lump disappears, your doctor can assume the lump was a cyst, and there’s no need for further tests.

An exception would be if the fluid is bloody; or if the lump doesn’t entirely disappear. In that case, the doctor may want to send some of the fluid to the lab for testing, to see if any cancer cells are present.

Some doctors aren’t ready to do an immediate fine needle aspiration, and will choose to send you for an ultrasound, instead. An ultrasound is an excellent tool for identifying cysts. It’s a painless test that clearly shows whether a mass in your breast is solid, or filled with fluid. If it’s fluid-filled, it’s a cyst. If it’s solid, you’ll need further diagnostic testing – and perhaps a biopsy – to determine just what the lump is.

If the ultrasound shows a fluid-filled mass, then the doctor may or may not drain it; this would depend on how large it is, whether it’s painful, and whether there’s any question about the potential of cancer somewhere within the cyst.

Are cysts always drained?

Unless a cyst is painful, there’s no need to drain it. Most women with cysts find they’re a one-time occurrence. The cyst may persist for quite awhile, but will gradually disappear on its own.

Some women have multiple/recurring cysts; they’re irritating, but not dangerous. In rare cases, cysts may be removed surgically; but this is only if a cyst is painful, and keeps coming back; or if there’s some question about it possibly being cancer.

Preventing cysts

There’s no proven strategy for preventing cysts, but anecdotal evidence suggests that eliminating caffeine from your diet, and reducing your sodium (salt) consumption, may both be helpful. Since cysts seem to be influenced by hormones, regulating your period via oral contraceptives is also an option.

The best way to prevent cysts is simply to grow older. Few postmenopausal women, unless they’re taking hormone replacement therapy, are bothered by cysts. So the older you get, the less you have to worry about cysts.

Breast cancer survivor and award-winning author PJ Hamel, a long-time contributor to the HealthCentral community, counsels women with breast cancer through the volunteer program at her local hospital. She founded and manages a large and active online survivor support network.

PJ Hamel
Meet Our Writer
PJ Hamel

PJ Hamel is senior digital content editor and food writer at King Arthur Flour, and a James Beard award-winning author. A 16-year breast cancer survivor, her passion is helping women through this devastating disease. She manages a large and active online survivor support network based at her local hospital and shares her wisdom and experience with the greater community via HealthCentral.com.