Cancer Women's health

What’s a polyp and what’s a fibroid?

women with question marks around her

I was having dinner with a friend recently, and the topic of uterine fibroids came up (as it does, over a glass of red wine).

As we talked about our lady parts in hushed voices in the fancy French restaurant, we got ourselves mixed up about polyps and fibroids, the symptoms of each, and if either are more likely to be cancerous. Rather than asking Dr. Google, I decided to ask gynecologist and obstetrician Dr. Leslie Po and gynecologic oncologist Dr. Lilian Gien to help us understand these common growths.

The uterus, Dr. Po explained, is made up of many layers of tissue. The innermost layer is called the endometrial lining. Quick refresher: during your menstrual cycle, the lining builds up and then sheds (that’s your period). Then, the cycle starts over again.

“Sometimes, the lining overgrows in one particular spot. This is how a polyp forms,” Dr. Po said. “Polyps can grow anywhere in the uterus and sometimes in the cervix.”

With polyps, most women will not have any symptoms. Some will have small amounts of bleeding in between their periods. Others will have heavy bleeding at the time of their periods.

These growths are usually benign (non-cancerous), said Dr. Gien.

“But if you have gone through menopause and you have any bleeding after menopause, talk to your doctor,” she said. “In this situation, it is very important have the polyp removed to look for endometrial cancer.”

Risk factors for endometrial cancer include obesity, history of an abnormal menstrual cycle, polycystic ovaries, being on the drug tamoxifen and not having had children.


A fibroid is also a tissue growth in the uterus, but on the muscle rather than the lining.

Dr. Po said fibroids can have many shapes, sizes and locations. Three spots are most likely to develop fibroids: in the inside of the uterus (submucosal), within the walls (intramyometrial), on the outer surface (subserosal) or attached by a stem (peduculated).

Symptoms of fibroids depend on the where it’s located, Dr. Po said.

“Many women with fibroids will have no symptoms. If the fibroids are located on the surface of the uterus, you might feel pressure symptoms (like feeling the urge to void or constipation). If the fibroid is inside the uterine cavity or pushing on the endometrial lining, you can get crampy, painful periods and heavy bleeding during your period.”

For premenopausal women, the fibroid can grow with the changing hormones of the menstrual cycle, Dr. Gien said. After menopause, the fibroids usually stop growing.

Dr. Gien said it is very rare that a fibroid is a cancerous growth. Sarcomas can grow in the same areas, and are rare. Your doctor will review your risk factors and how fast the fibroid is growing, though rapid growth doesn’t necessarily mean it’s cancerous, Dr. Gien said.

“But again, if you have gone through menopause and you have bleeding, see your doctor,” she said.

Diagnosis and treatments for polyps or fibroids

Sometimes, polyps or fibroids are discovered when a woman is trying to get pregnant, as both can affect fertility. Or, a woman has symptoms like abnormal bleeding that cause her to reach out to the doctor.

“First, your doctor might ask you to do an ultrasound to find out if you have polyps or fibroids,” Dr. Po said. “Sometimes you might need to do a special ultrasound called a sonohysterogram. This is where fluid is put into the uterine cavity to help the radiologist see inside your uterus.”

Sometimes polyps just go away on their own. You and your doctor may choose to keep an eye on them over time. If the polyp is larger than 1 cm or you are post-menopausal, you might need a procedure called a hysteroscopy. This is where the gynecologist puts a telescope attached to a camera to help see into your uterus. Once she/he looks into the uterus and sees the polyp, this can be removed directly. If you are at risk for endometrial cancer, the doctor might do an endometrial biopsy to ensure there are no cancerous cells.

For fibroids, again, you and your doctor may watch them. If you have no symptoms, you will likely receive no active treatments. Sometimes, though, the fibroids are surgically removed. Your surgeon might send the fibroid for analysis to rule out cancer.

The “Coles Notes” version of this blog

So in short — if you ever find yourself discussing polyps and fibroids over a glass of red wine — it’s important to remember that these growths are very common in pre-menopausal women, often don’t cause any symptoms, and are rarely cancerous. If you are post-menopausal or have other risk factors and have abnormal bleeding, talk to your doctor.

About the author


Alexis Dobranowski

Alexis Dobranowski is a Communications Advisor at Sunnybrook.

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