Reading "fibroadenoma" on a breast ultrasound, mammogram or biopsy report

The words next to it

Words you may see beside fibroadenoma on a report, and what each one changes.

BI-RADS 3, probably benign

The chance of cancer is 2% or less. The category is meant for lumps that show the benign features, not for a radiologist who can't decide.

Echogenic pseudocapsule

A thin bright rim around an oval or lobulated lump. With no suspicious features, it points strongly to benign, though growth between scans still counts.

Irregular, indistinct, angular, not parallel

The opposite of the benign words. In one study, any of these showing up on a follow-up scan moved the lump to BI-RADS 4, where the plan turns to a biopsy.

Simple or complex fibroadenoma

Biopsy wording. Both are fibroadenomas. Complex means the pathologist saw extra cell changes, such as sclerosing adenosis or calcifications, and complex ones tend to be bigger and to turn up in older people.

No atypia

Biopsy wording for cells that look as expected under the microscope. In one center's practice, a fibroadenoma with no atypia and no hint of phyllodes generally isn't removed unless it causes symptoms or reaches a certain size.

Fibroepithelial lesion, phyllodes not excluded

Biopsy wording for a sample that fits a fibroadenoma or a benign phyllodes tumor without saying which. The two can be hard to tell apart on a needle sample.

What follows a probable fibroadenoma

With BI-RADS 3, the usual plan is an ultrasound at 6 months, then at 12 and 24 months. Those scans stand in for a biopsy now, and two years without change is what they're built to show.

Watching only works if the scans happen. Missed follow-ups are a risk with this plan, so write down all three dates, not just the first.

A biopsy comes back into the plan if the lump grows or picks up one of the suspicious words above. That word can land hard. Most ultrasound findings that go to biopsy turn out not to be cancer.

Once a biopsy has confirmed it

Not every confirmed fibroadenoma needs treatment. Some stop growing or even shrink on their own, and the care team just checks that they don't grow.

The usual reasons to remove one are rapid growth, a size over 2 cm, symptoms, a lump that didn't look like a typical fibroadenoma on imaging, and the person wanting it out.

Questions to ask the doctor

• Is my lump BI-RADS 3, and what are the dates for each follow-up scan?
• What change in size or feel should make me call before the next scan?
• Would you biopsy this now instead of watching it, and what would change your mind?
• Does my biopsy result match what the ultrasound showed?
• Does my pathology report say complex, atypia or phyllodes, and does that change the plan?
• Does this change when I have my regular screening mammograms?

Often on the same report

• BI-RADS 3

  Probably benign. The finding has a very low chance of being cancer, below 2%.

• BI-RADS 4

  Suspicious. The radiologist found something that could be cancer. It's often split by level of concern: 4A means a 2% to 10% chance of cancer, 4B means 10% to 50%, and 4C means 50% to 95%.

• Hypoechoic

  Darker than the tissue around it on an ultrasound image. It describes how a spot looks on the screen, not what it's made of.

• Well-circumscribed

  The edges of the spot are clearly outlined against the tissue around it. In breast masses, for example, clearly outlined edges are more often benign (not cancer) than blurry or spiky edges.

• Atypia

  Cells that don't look normal under the microscope. Atypical cells can turn out to be harmless, precancerous, or cancer, so the word alone doesn't say which.

• Benign calcifications

  Calcium deposits with a look the radiologist recognizes as not cancer. On a mammogram these include large coarse, popcorn-shaped or rod-like deposits, and calcium in blood vessel walls. They're counted as a benign finding.

Questions people ask

Are fibroadenomas in the breast a serious problem?

Usually not. A fibroadenoma is a benign solid lump, and simple fibroadenomas don't seem to raise breast cancer risk. Complex ones, which show extra cell changes under the microscope, may increase the risk slightly more than simple ones.

Can a fibroadenoma turn out to be cancer?

A confirmed fibroadenoma is benign, and when the biopsy matches how the lump looked and felt, that diagnosis is highly accurate with few missed cancers. The doubt sits elsewhere: a "probable fibroadenoma" on a scan hasn't been tested yet, and a needle sample sometimes can't rule out a phyllodes tumor, which can keep growing where a fibroadenoma stops.

What does a calcified fibroadenoma mean on a mammogram?

Older fibroadenomas, usually in people past menopause, can calcify as they shrink. On a mammogram that often shows as coarse "popcorn" calcification, the classic look of an aging fibroadenoma.

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