A fibroadenoma is a benign breast lump, which means it’s not a form of cancer. However, if you’re treating breast cancer or are a breast cancer survivor, these harmless lumps may still cause anxiety.

It may help to understand what a fibroadenoma is, what they feel like, and what to say when you talk to your doctor about this noncancerous breast condition. Here’s what you need to know so you can make informed choices about your healthcare.

What Is a Fibroadenoma?

A fibroadenoma is a lump in your breast that you or a healthcare provider can usually feel when they examine your breast tissue. These types of lump are the most common type of benign breast tumor.

No one knows what causes them, but they may be connected to the effects of estrogen in your body. However, not everyone with estrogen gets them, so there are likely other factors.

Fibroadenomas usually develop around the milk production system in the human breast. This system is made up of lobules (the glands that make the milk) and the ducts (tubes that carry the milk from the lobule to the nipple).

A fibroadenoma develops around a lobule. Duct tissue and other tissue can grow around the lobule, creating the firm lump that you can feel when you touch your breast.

Most of the time, fibroadenomas stay the same size. But sometimes, they get smaller or even disappear.

Fibroadenomas may get bigger when your hormones are fluctuating. This includes during the teenage years, when you’re pregnant or breastfeeding, or if you’re taking hormone therapy for menopause. In these cases, they may shrink again when your hormones return to steady levels.

What Do Fibroadenomas Feel Like?

Health experts say that most fibroadenomas are between 1 and 3 centimeters across, but they can also be bigger. It may feel like you have a small marble inside your breast that moves a lot.

Sometimes, you may have fibroadenomas that show up on a screening but are too small for you to feel. It’s possible to have more than one fibroadenoma at a time in the same breast.

Fibroadenoma symptoms include a lump that usually feels smooth, with clean borders that aren’t jagged. Most fibroadenomas also tend to move around easily, rather than being anchored in one place under your skin. They may feel like they’re made of rubber, though some feel firmer than that.

Most of the time, fibroadenomas don’t hurt. Some people find that theirs are tender, or that they become painful around their period. The bigger your fibroadenoma is, the more likely it is to be painful.

Who Gets Fibroadenomas?

There aren’t a lot of risk factors for fibroadenomas, but they most commonly show up in women of reproductive age, between ages 15 and 35. They’re most common in your 20s and 30s, but they can show up at any age, even after menopause (though this isn’t common). Black people have a slightly higher risk of developing them than people of other races.

While it’s extremely rare, men occasionally develop fibroadenomas. The treatment is the same regardless of a person’s sex.

There are a few things that might raise your risk of developing a fibroadenoma. These include getting your period at a younger age than most people do and never having given birth. If your hormones are out of balance or you’re on hormone therapy, you’re also more likely to get them.

Some people may have a genetic risk for developing fibroadenoma of the breast, too. If you have a family history of them, or a close relative who has them — like a mother, sister, or daughter — you might be more likely to develop them, too. Researchers don’t yet know exactly what genes are involved or how this works.

Do Fibroadenomas Require Treatment?

Most fibroadenomas don’t raise your risk of breast cancer. The only exception to this is complex fibroadenomas, which may raise your risk very slightly.

Because of this, most of the time, fibroadenomas don’t need treatment. As noted above, they may go away on their own.

Sometimes, a breast biopsy or surgical removal of a fibroadenoma will be required to diagnose a fibroadenoma. Fibroadenomas can sometimes appear like breast cancer in your imaging tests (mammogram and ultrasound), so your doctor may not be able to diagnose you unless they examine a sample of the tissue.

If having a fibroadenoma causes a lot of anxiety for you, removing it can help with this, too. Researchers are working to figure out if there are any other effective ways of diagnosing a fibroadenoma and relieving anxiety, like a blood test or certain types of imaging tests.

Some doctors may recommend surgically removing giant or juvenile fibroadenomas. Others might recommend surgery, if the fibroadenomas hurt a lot or are growing fast, or if they change the way your breast looks. Another option is to monitor fibroadenomas every three to six months to see if they’re changing before making decisions about treatment.

How To Talk to Your Doctor About Fibroadenomas

You should always talk to a healthcare professional as soon as you notice breast changes. If you’re already living with breast cancer, this will probably be someone on your oncology team.

It’s your doctor’s job to help you assess what’s going on with your body. This includes looking at breast lumps, determining what caused them, recommending treatment if necessary, and coming up with a treatment plan for you. If you notice lumps after breast reconstruction, after biopsy, or any other time, they can figure out what’s causing them and recommend treatment or monitoring if necessary.

If you have a new or changing breast lump, your doctor will likely order a mammogram or a breast ultrasound to get more information about it. The test they use will be determined by your age and breast cancer history.

If you’re concerned that a lump might be cancer or you’re worried about a breast cancer recurrence, talk to your doctor. They can also explain potential risks and benefits associated with treating a fibroadenoma.

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On MyBCTeam, people share their experiences with breast cancer, get advice, and find support from others who understand.

Have you experienced fibroadenomas during or since breast cancer treatment? How did they affect you? Let others know in the comments below.