Breast Cyst

What is a breast cyst?

A breast cyst is a fluid-filled sac (like a tiny balloon) inside the breast. Breast cysts are common in women. They might cause a little pain, but they are usually benign (not cancerous).

Symptoms of a breast cyst

• A smooth, round, movable lump in the breast
• Breast pain or tenderness 
• Swelling or lump size that changes with the menstrual cycle 
• Nipple discharge (clear, yellow, or dark brown, rarely bloody)

What causes a breast cyst?

• Imbalance of hormones, especially estrogen
• Blockage in milk ducts leading to fluid buildup

Risk factors:

• Age (most common between 35–50 years)
• Perimenopause (hormonal changes increase likelihood)
• Family history of fibrocystic breast changes

Medications that could affect a breast cyst:

• Hormone replacement therapy (HRT)
• Birth control pills (may increase or sometimes reduce cyst formation)

How is a breast cyst diagnosed?

• Clinical breast exam (feeling the lump) 
• Ultrasound (to see if the lump is fluid-filled or solid)
• Fine-needle aspiration (withdraws fluid to confirm cyst)
• Mammogram (to rule out other breast changes)

Can a breast cyst be prevented or avoided?

Breast cysts cannot be fully prevented, but steps like limiting caffeine, maintaining a healthy weight, and monitoring hormone use may reduce risk or discomfort.

Breast cyst treatment

What is breast cyst aspiration?

This is a procedure done in your doctor’s office, surgery center, or hospital. Your doctor will use a small needle to withdraw (aspirate) a small amount of fluid from the breast cyst.

When is breast cyst aspiration recommended?

This procedure is recommended when a breast lump you have detected feels painful. You may worry about cancer. However, most breast lumps are not cancerous. Breast cyst aspiration can help your doctor find out if the lump you feel is a cyst or a cancerous tumor. The cyst fluid is sent to a lab for testing.

How is breast cyst aspiration performed?

First, your doctor will numb the skin around the lump. Then, they will insert a small needle into the breast lump. They may use ultrasound to get a better picture of the lump and to guide the needle. Using a syringe, your doctor will try to pull fluid from the lump. There could be several results from the aspiration:

• The lump is a cyst that contains watery fluid.The cyst goes away after it is drained. You do not need other tests.
• The lump contains bloody fluid.Your doctor will send the fluid to a lab to find out what it is. You may or may not need further testing.
• The lump is solid and does not contain fluid.Your doctor will likely recommend imaging tests. This could be an ultrasound or a mammogram. These will give your doctor a better look at the lump. Your doctor may want to remove a small bit of the lump’s tissue and send it to a lab to be examined. At the lab, the fluid or sample from the lump can be examined under a microscope to look for cancer cells.

What are the benefits of breast cyst aspiration?

Your doctor may be able to diagnose your breast lump on the same day that you get the aspiration. If the lump is clearly a cyst, you will know right away. You might not need to have other tests performed.

Things to consider

What are the risks of breast cyst aspiration?

Before you have breast cyst aspiration, your doctor will discuss possible problems. You might have some discomfort where the needle goes in,or you might have a little bruise on your breast. You could develop an infection where the needle goes in. But these complications are uncommon.

Do I need to see my doctor again after I have breast cyst aspiration?

Yes. If the lump in your breast is a cyst and it is drained successfully, your doctor will want to check the area in 4 to 6 weeks. They will want to make sure the cyst has not filled with fluid again. This follow-up visit is important. A cyst that refills with fluid can be a problem. If you have a cyst that refills or you develop a new cyst, call your doctor.

Living with a breast cyst

• Most breast cysts are harmless and do not increase breast cancer risk.
• Regular self-exams and follow-up imaging help track changes.
• Some women may experience recurrent cysts and breast discomfort.
• Emotional reassurance and routine monitoring are important for peace of mind.