It’s a moment that can weigh on your mind—feeling a lump in your breast. What could it mean for your health? If it’s a breast cyst, probably nothing serious.
These common lumps are rarely cancerous, and they don’t increase your risk of breast cancer. Here’s what to know about breast cysts and why they shouldn’t worry you too much (although your regular medical provider should definitely check them).
What Is a Breast Cyst?
A type of breast lump, a breast cyst is a fluid-filled sac that can form anywhere in the breast. They often develop in the milk ducts behind the nipple.
Some cysts are too small to feel, but others can be up to 2 inches across. You may be able to feel these larger lumps, which can be round or oval in shape. They’re usually soft and feel different from the rest of your breast tissue.
3 Types to Know
Breast cysts come in three types:
- Simple: completely filled with fluid
- Complicated: mostly fluid with some bits of solid material floating around
- Complex: has some solid parts or thick outer walls
Simple cysts are the most common type, and they’re generally not cancerous. Complicated and complex cysts are more likely to be breast cancer, but that’s uncommon, too.
What Causes These Lumps?
Experts aren’t sure what causes breast cysts, but they think hormones may play a role. Why? Because cysts often occur before menopause, when hormone levels naturally rise and fall. Breast cysts are also common in women who take hormone replacement therapy.
Who Gets Breast Cysts?
Breast cysts are extremely common, and they can occur at any stage of life. You’re more likely to develop them, though, if you’re in your 30s or 40s, according to the American Cancer Society.
Do Breast Cysts Hurt?
Breast cysts can hurt, especially right before your period. Your hormone levels rise and fall as part of the menstrual cycle, and this can cause breast cysts to swell and become uncomfortable.
Symptoms of breast cysts may include:
- A soft, movable lump that may be tender
- Breast pain or tenderness
- Nipple discharge
How Cysts and Cancerous Lumps Differ
Distinguishing between a breast cyst, which is typically benign, and a cancerous lump can be tricky. Certain signs, however, may offer clues.
Start with shape. Cysts tend to have a recognizable shape, either round or oval. In addition, they usually have a clear-cut border. Cancerous lumps, on the other hand, can take many shapes, and they’re more likely to have an irregular border.
Next, consider how the lump feels. If it’s a cyst, all the fluid inside makes it feel soft. A hard mass is more likely to be breast cancer.
Then, take note of any symptoms. A breast cyst may be painful or tender, especially in the run-up to your period. A painless lump has a greater chance of being breast cancer.
Here’s where things get tricky: Cysts and cancerous breast conditions can look, feel and behave similarly. Some breast cancers, for example, may share symptoms or characteristics, such as pain and softness, with cysts. That’s why it’s always worth seeing a doctor if you feel a breast lump.
You’ve Found a Breast Lump. What’s Your Next Move?
Schedule an appointment with your primary care provider or gynecologist so they can examine the lump. You may not be able to see your provider right away. In the meantime, it’s normal to feel anxious about what the lump could be and where things might go from here. Here’s what you can do to help ease your mind until your evaluation.
4 Ways to Cope With Pre-Appointment Anxiety
1.    Remember, the odds are on your side. Remind yourself that the vast majority of breast lumps, including cysts, aren’t cancer.
2.    Talk to someone you trust. Share your feelings with a close friend or family member rather than ignoring or burying them.
3.    Make healthy choices. Eat nutritious foods, exercise on most days of the week, get at least seven hours of sleep a night and manage chronic conditions, such as diabetes. Prioritizing your health can help you feel in control in the face of uncertainty about a breast lump.
4.    Be kind to yourself. Set aside 15 to 20 minutes a day to do something that inspires or relaxes you, whether it’s walking a favorite trail, working on a craft project or listening to music.
What to Expect at Your Evaluation
Your physician will review your health history, including any conditions you’re managing. They may ask about your family medical history, too, including whether any close family members have been diagnosed with breast cancer, how you found the lump and any symptoms you have.
As part of the evaluation, the physician will feel the lump and carefully examine your breast for changes or differences compared with the other breast.
Next Steps
Your physician may order a mammogram or a breast ultrasound to examine the lump. A breast ultrasound can reveal whether it’s solid or filled with fluid.
If the physician diagnoses a cyst, especially a simple breast cyst, you may not need further tests or treatment, unless the lump is uncomfortable. In that case, applying heat or taking over-the-counter pain medications may give relief.
A procedure called fine needle aspiration (FNA) can address two problems at once: confirming the diagnosis of a cyst and treating symptoms. Your doctor may order an FNA if they suspect a cyst.
During the procedure, a physician places a hollow needle in the lump. If the lump is filled with fluid, it’s likely a cyst, and the physician can dissolve it by draining the fluid. That leaves you with less pain and more peace of mind.
A pathologist will look at a sample of the fluid or tissue under a microscope to check for cancer cells. If the results are inconclusive, your doctor may want to perform a different type of biopsy, such as a core needle biopsy, to learn more.
Want to stay a step ahead of breast cancer? A screening mammogram can find cancerous changes long before you can feel them. Request an appointment for your annual mammogram today.