The story on breast fibroadenomas

The story on breast fibroadenomas

The 22-year-old woman finds a firm lump in her breast. Panic! She knows the drill: Breast lump equals breast cancer!

Except, fortunately, that the terrifying breast lump in a teenage girl or a woman in her 20s almost always turns out to be a fibroadenoma, a common and harmless tumor. It is clearly benign, with no connection to breast cancer. (“Tumor” is just medical lingo for any abnormal swelling or growth in the body that doesn’t serve any necessary function–although it may not cause any problem either.)

The usual scenario has the girl or young woman taking a shower or putting on her bra when her fingers accidentally brush against a painless, marble-sized breast lump. These tend to be firm, round or oval, smooth, and easily movable. In fact, their tendency to skitter away from fingers has led some women to label them breast “mice.”

While fibroadenomas can certainly occur in women in their 30s and 40s, the peak time seems to be in the early years of menstruation, when the hormonal cycles are still “learning the ropes.” The lumps can range from about 1/5th of an inch to the size of a lemon or even larger, with the largest ones often found in teenagers. Most stop growing at about one inch (2.5 centimeters).

Cause: generally unknown. There is some evidence that birth control pills before age 20 might increase risk somewhat–but also evidence that they don’t.

Estimates of how many women develop a fibroadenoma at some time in their lives range from 1-in-6 women to 1-in-10 women. For most of those women, it happens only once, although some develop multiple fibroadenomas, either at one time or over the years. African-American women develop more fibroadenomas than white women, and often at a younger age.

Of course, the teenager or young woman discovering the lump doesn’t know yet whether it’s cancer or not. Any breast lump that doesn’t go away after her period calls for a trip to the doctor or other healthcare provider–and a real diagnosis rather than a guess.

After talking with the woman and doing a physical exam, the doctor often has a pretty good sense that this solid tumor is a fibroadenoma rather than a cancer. A “pretty good sense” is not enough, however. Luckily, fibroadenomas have a distinctive smooth rounded appearance when sound waves pass through the tumor during a breast ultrasound exam, the preferred test for women too young for mammograms.

The common next step is getting some cells and preferably some tissue from the tumor and looking at it under a microscope to find out for sure what it is: the diagnosis. Usually this calls for a core biopsy (also called a core needle biopsy) in which a special hollow needle is inserted into the tumor through a nick in the skin. Several tiny cores or tissue specimens are “vacuumed” out to sample different areas of the tumor.

The pathologist, the doctor examining the cores of tissue under the microscope, most often makes the diagnosis of a single simple fibroadenoma. This is the usual fibroadenoma, which combines some glandular (“milk-producing”) breast tissue and some fibrous supporting tissue. The word fibroadenoma comes from this combination of fibrous tissue and the word adenoma, a benign tumor of glandular tissue. Simple fibroadenoma does not increase future breast cancer at all.

Occasionally the pathologist finds complex fibroadenoma, which adds some other benign but somewhat riskier breast change, such as large cysts or sclerosing adenosis, to the fibroadenoma. The woman with a complex fibroadenoma or with multiple fibroadenomas faces a slightly increased risk of developing breast cancer compared to the woman without these conditions.

It used to be that, with a firm diagnosis of simple fibroadenoma, a surgeon would always remove the fibroadenoma during a surgical lumpectomy (500,000 fibroadenoma lumpectomies a year in the U.S.!). However, that seemed like overtreatment to many doctors and women. After all, if the fibroadenoma wasn’t growing quickly or causing any symptoms–and definitely wasn’t connected to cancer–there was no immediate reason to remove it. While fibroadenomas would grow with pregnancy or certain hormonal treatments, they also tended to get smaller or disappear on their own with menopause.

Often watchful waiting is the preferred treatment now. A repeat ultrasound may be scheduled in a few months to check for any changes. If it becomes painful or causes other symptoms, or if the woman is very concerned for any reason, a lumpectomy can be performed.

Other treatment options are more minimally invasive than a lumpectomy. One example is cryoablation, in which a special ultrasound-guided probe is inserted into the tumor through a slit in the skin to freeze the fibroadenoma, ablating it rather than removing it. Over several months, the tumor dies and is absorbed by the body.

Percutaneous excision is another possibility. A different type of ultrasound-guided probe (this one with a vacuum, often with the brand name Mammotome™) is inserted through a small slit in the skin to cut the whole fibroadenoma into sections and then extract it all.

Still another technique, percutaneous radiofrequency-assisted excision, uses a wand with a knife tip heated by radiofrequency. This separates the tumor easily from the normal tissue so that wires and tiny robotic “arms” can extract the whole tumor in one piece through a slit in the skin.

With Novilase™, a laser probe inserted through the skin into the tumor destroys the fibroadenoma with laser energy rather than removing it. A current clinical trial, called the American Breast Laser Ablation Therapy Evaluation (ABLATE), is examining long term safety and effectiveness of the technique, although some centers use it already.

All these newer techniques promise smaller scars and less pain than a traditional lumpectomy, but many exclude certain patients (such as those with larger tumors) and may not be locally available.

The most important thing to know, however, is that fibroadenoma, while scary at first, is common in young women and generally medically harmless.

Kerry Anne McGinn