Recently, The Bold Type actress Katie Stevens [1] shared on Instagram that she'd found a lump during a breast self-exam. "I had never felt one before, and it didn't feel like normal breast tissue," the 26-year-old wrote [2]. "I was in a panic, so emotional... My wedding is soon, I'm in the middle of shooting this season. I needed clarity." After making an appointment with a specialist and getting an ultrasound, she found out that it was a benign tumour called a fibroadenoma, which is, as you'll soon find out, common. "I feel very lucky and grateful and was able to breathe a huge sigh of relief," Katie said. POPSUGAR spoke to Neil Iyengar [3], MD, a medical oncologist with an expertise in breast cancer from Memorial Sloan Kettering in New York City, about what these tumours are and how they differ from cancer.
What Is a Fibroadenoma?
Fibroadenomas are very common, Dr. Iyengar told POPSUGAR. In fact, fibroadenomas are the most common type of benign breast tumour [4]. And "in people who have some kind of tumour in their breast that's benign, about 50 percent are fibroadenomas," he said. According to the American Cancer Society, they're most often found in women in their 20s or 30s [5], though they can be found in the older population as well. They're categorised as benign breast disease and considered proliferative breast lesions, which have a slight increase in breast cancer, "somewhere between one and a half to two times that of the general population," Dr. Iyengar clarified. (Another common type of proliferative breast lesion is a papilloma [6].)
To detect a fibroadenoma, you'd either feel it yourself or it would come up in a routine mammogram. It's hard even for a medical professional to determine whether a tumour is cancerous or benign just by touching it, Dr. Iyengar said, but there are some features to fibroadenomas that are distinctive. "Usually, a benign tumour like a fibroadenoma is a really well-defined area. It feels like a sphere almost," he explained. It's often less than two centimetres in size, though sometimes bigger. You can also typically move it around — it's not fixed to the chest wall — and it has a rubbery texture. If you can feel cancer in the breast, Dr. Iyengar noted, "it's a more ill-defined lesion. It may not be a nice clean sphere. It's usually fixed to the chest wall so you can't move it that easily. But, again, it's incredibly difficult to differentiate just by feeling it."
How Is a Fibroadenoma Diagnosed and Treated?
The standard way to diagnose a fibroadenoma would be an ultrasound, Dr. Iyengar said. Sometimes, if there's any kind of question about it, a biopsy is recommended. "Once an ultrasound diagnoses a fibroadenoma, then usually it's followed up with repeat ultrasound and breast exams every three to six months. And, as long as there are no changes, then that's pretty clearly a fibroadenoma. If it's growing or it looks different at all, then it needs a biopsy," he noted.
Fibroadenomas can often go away, especially in premenopausal women, Dr. Iyengar said, or they may linger. The most common situation he's seen, for example, is a premenopausal woman being diagnosed with a fibroadenoma that either goes away on its own or remains until menopause. At that point, because of the fluctuations in hormones, it might start to shrink. He added that fibroadenomas can grow in size during pregnancy because of increased oestrogen, but, typically, these benign tumours shrink over time.
If fibroadenomas do persist, they just need to be monitored with mammograms and ultrasounds moving forward (Katie wrote online that she has to monitor hers every six months). Some women want to get rid of the tumour for aesthetic reasons, even if there isn't a need to remove it, Dr. Iyengar said, though that's normally not recommended if the tumour is on the larger side. The excision itself can cause scarring or dimpling in the breast, he explained. "If it's small, then usually it can be completely removed with an excisional biopsy without much scarring. But if it's big, like greater than two centimetres or greater than five centimetres, then there's probably going to be some amount of deformation."
Does a Fibroadenoma Increase Your Chances of Getting Breast Cancer?
As mentioned earlier, having a fibroadenoma generally gives you a minimal increased risk of developing breast cancer (note: Dr. Iyengar said it's possible to have a fibroadenoma and breast cancer at the same time, but fibroadenomas really only increase your chances of developing breast cancer by a small amount). On the other hand, simple breast cysts, considered nonproliferative breast lesions, have no increased risk of breast cancer. The third category of benign breast disease, atypical hyperplasia [7], does increase the risk of breast cancer. It isn't breast cancer, Dr. Iyengar said, but you'd need to think about strategies to reduce that risk.
What Katie has is a simple fibroadenoma, and about 20 percent of people with this type of benign tumour have multiple ones, Dr. Iyengar said. Complex fibroadenomas are different and do have to be removed because the risk of breast cancer, though still on the lower side, is slightly higher than with a simple fibroadenoma. "Complex just means that when you look at it under the microscope, you start to see some features that look different than normal breast tissue," he said. "When you look at a simple fibroadenoma under the microscope, it just looks like an overgrowth of normal breast tissue. In a complex fibroadenoma, you start to see some slightly abnormal features."
Dr. Iyengar recommends that women 40 and older get annual mammograms. Those who have a strong family history of breast cancer or a genetic mutation, like BRCA [8], might want to have a conversation with their doctor about whether or not they should be doing mammograms more than once a year, he said, noting that "some people benefit from adding a breast MRI or a breast ultrasound and increasing the frequency to every six months." He also recommends having a breast exam by your GP or gynaecologist at least one time every year. If you're interested, here are instructions for performing a breast self-exam [9], too.