Can Fibroids Be Cancerous? What the Real Risk Is

What Is a Fibroid? Is It a Tumour?

A fibroid is a growth made of muscle tissue in the wall of the uterus. Its medical name is leiomyoma. It is also called a myoma, and in Hindi, rasoli.

Yes, a fibroid is a type of tumour. But “tumour” only means a lump of extra tissue. It does not mean cancer. Fibroids are benign tumours: they do not spread to other parts of the body.

Fibroids are extremely common. In US studies, about 70% of white women and 80% of Black women have fibroids by age 50. Most cause no symptoms. About 15% to 30% of women with fibroids develop severe symptoms.

Learn more on our Uterine Fibroids page.

Can a Fibroid Turn Into Cancer?

Quick answer: No. Doctors do not believe a normal fibroid changes into cancer.

The rare cancer that can look like a fibroid, called leiomyosarcoma, is thought to be a different growth from the beginning. It is not an old fibroid that has “gone bad.”

This also means that leaving a fibroid untreated does not make it more likely to become cancer. Treatment decisions are based on your symptoms and plans, not on fear that the fibroid will turn cancerous.

How Often Are Fibroids Actually Cancer?

Quick answer: Rarely. Among women who have surgery for what looks like a fibroid, a small number turn out to have a hidden uterine cancer. Among all women with fibroids, most of whom never need surgery, the chance is lower still.

Table 1: The real numbers

Why the numbers vary: they come from women who had surgery, often because their growth was large, fast-growing or causing symptoms. That group has a higher risk than women with small, quiet fibroids found on a routine scan. Some medical organisations have reported lower estimates than the FDA’s.

The most important point: age matters. The risk is very low in younger women and rises after menopause.

Fibroid vs Cancer: How Are They Different?

Table 2: Fibroid, uterine sarcoma and endometrial cancer compared

Fibroids usually stop growing at menopause and may shrink. This is why a growth that keeps growing after menopause needs closer evaluation.

Symptoms: Fibroid or Something More Serious?

Quick answer: Fibroid and cancer symptoms can overlap, so symptoms alone cannot tell them apart. Certain signs, especially after menopause, mean you should see a gynaecologist promptly.

Table 3: Common fibroid symptoms vs signs to get checked soon

Having a sign from the right-hand column does not mean you have cancer. It means you need a proper check-up rather than waiting.

Is a fast-growing fibroid cancer? Not usually. Fibroids can grow quickly in younger women, especially during pregnancy. Rapid growth matters most after menopause, when fibroids should be shrinking.

How Doctors Tell a Fibroid From Cancer

Quick answer: Ultrasound is the first test. MRI and tests of the uterine lining may follow. A biopsy is the only way to be sure, but a biopsy of the uterine lining cannot always reach a growth in the muscle wall.

Table 4: Tests and what they show

Transvaginal ultrasound is the standard imaging test for fibroids, but it has not been shown to tell leiomyosarcoma apart from a fibroid. That is why your doctor looks at the whole picture: your age, symptoms, scan pattern and how the growth changes over time.

For cancer-specific evaluation, see Uterine Cancer Diagnosis and Endometrial Cancer Diagnosis.

What Size of Fibroid Is Dangerous?

Quick answer: Size alone does not mean cancer. A large fibroid, even 10 to 12 cm, is usually still benign. But size affects symptoms, fertility and the type of treatment.

Table 5: What fibroid size usually affects

Position often matters more than size. A small fibroid inside the uterine cavity (submucosal) can cause heavier bleeding and fertility problems than a larger one on the outside (subserosal or exophytic).

Can Cancer Be Mistaken for a Fibroid?

Yes, rarely. This is the main reason fibroids and cancer get linked. A uterine sarcoma can look like a fibroid on ultrasound. Sometimes it is only found when the tissue is examined after surgery.

What this means for you if you need surgery: ask your surgeon how the fibroid will be removed. In laparoscopic surgery, large fibroids are sometimes cut into small pieces inside the body (morcellation). Regulators have warned that if an unexpected cancer is present, this can spread it. Many surgeons now use a protective bag (contained morcellation), or choose another approach for women at higher risk. It is a reasonable question to ask. See Fibroid Removal Surgery.

Do Fibroids Increase the Risk of Other Cancers?

Fibroids and Fertility

For many women, the bigger question is not cancer but whether fibroids will affect pregnancy. Fibroids, especially those inside the uterine cavity (submucosal), can be linked with difficulty conceiving.

Table 6: Fibroid type and fertility

If you are trying to conceive, a fibroid mapping scan helps decide whether a fibroid needs treatment before trying, or before IVF. See also Female Fertility Treatment.

Myths and Facts

 Common myths

When to See a Doctor

Book a gynaecology consultation if you:

• have bleeding after menopause
• have been told a fibroid is growing after menopause
• have very heavy periods, or feel tired or breathless (possible anaemia)
• have pelvic pressure, frequent urination or a swollen lower abdomen
• are trying to conceive and have been told you have fibroids

Worried about a fibroid on your scan? Our gynaecologists in Secunderabad can review your reports and advise whether you need further tests or simply monitoring.

• Book a Fibroid Mapping Scan
• Book a Consultation
• Call +91 8790337035 or 040 45678899

Sources:

• US FDA: Updated Assessment of Power Morcellation and Sarcoma Prevalence
• CURE: FDA review summary on occult sarcoma and leiomyosarcoma rates
• MDedge: FDA 2017 updated assessment
• Merck Manual: Uterine Fibroids
• WebMD: Fibroids and age
• StatPearls: Uterine Fibroids

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