Are Fibroids Cancerous?


Uterine fibroids are completely benign tumors that develop from smooth muscle tissues within the uterus. Fibroids are the most common non-cancerous pelvic tumors in women, affecting 20–80% of pre-menopausal women. 

During reproductive years, especially during pregnancy, leiomyomas can increase in size and typically reduce during post-menopausal period. 

You may wonder,  ‘ are fibroids cancerous?’ 

The answer is that a benign fibroid can, in extremely rare cases, transform into a Leiomyosarcoma, a rare type of malignant growth.

What are Uterine Leiomyosarcomas?

A uterine leiomyosarcoma is a rare cancer that arises from the muscle layer of the uterus. Both fibroids and leiomyosarcoma involve the muscle layer of the uterus. Fibroids are benign (non-cancerous) growths while leiomyosarcomas are cancerous growth and  invade surrounding structures and may spread (metastasize) to distant organs especially the lungs and liver,  causing life-threatening complications. 

Cancerous uterine fibroids (Leiomyosarcomas) occur in less than one in every 1,000 fibroid cases, and doctors believe they develop on their own rather than from benign fibroids that already exist.

Symptoms of Leiomyosarcomas

Clinical manifestations of uterine sarcomas and fibroids are similar, with increased uterine size, abdominal pain and per vaginal bleeding. The most common symptom is abnormal bleeding from the vagina and the uterus. 

Larger cancerous uterine fibroids frequently start to cause:

  • Unusual bleeding
  • Vaginal discharge that is abnormal
  • Urination and bowel movement changes 

Other symptoms, which are more general and common in many types of cancer, include:

  • Fatigue and fever
  • Unknown cause of weight loss
  • Genral feeling of illness.
  • Nausea
  • Vomiting

What percentage of fibroids are cancerous?

Leiomyosarcoma is an extremely rare form of cancer, estimated to occur in 6 out of every 1,000,000 women in the United States each year. 

The vast majority of fibroids are non-cancerous (benign). Less than 1% of uterine fibroids are estimated to have malignant (cancerous) characteristics.  Many researchers argue that malignant transformation of fibroids is unproven. 

It’s important to note that fibroids are generally benign growths and do not inherently possess cancerous properties. Regular monitoring and consultation with a healthcare provider can help address any concerns and determine appropriate management strategies based on individual cases. 

Are uterine fibroids dangerous?

In general, uterine fibroids are not considered dangerous. They are benign (non-cancerous) growths that often develop in a woman’s uterus while she is in her childbearing years. Apart from heavy menstrual bleeding, pelvic pain or pressure, they can also lead to reproductive issues.

In certain cases, fibroids may lead to complications, such as:

  • Severe Menstrual Bleeding: Fibroids can cause heavy or prolonged menstrual bleeding, leading to anemia in some cases.
  • Pelvic Pain: Large or multiple fibroids may cause pelvic pain or discomfort.
  • Reproductive Issues: Fibroids can impact fertility or cause complications during pregnancy and labor.

While most fibroids do not pose a direct danger, their impact on a person’s quality of life varies. Treatment options, including medication, minimally invasive procedures, or surgery, are available to address symptoms or, in some cases, remove the fibroids. It’s essential to consult with a specialist for personalized advice and management.

Fibroid Vs Leiomyosarcoma:

Fibroids are the most common tumors affecting women and often appear during childbearing years. While LMSs most frequently occur after menopause. The average age at diagnosis is 60 years.

A new or rapidly enlarging uterine mass and/or  bleeding in a postmenopausal woman should raise the suspicion for malignancy.

Although uterine sarcomas are rare, it is vital to raise suspicion on imaging for appropriate surgical planning. MRI is the best modality for assessing uterine sarcomas and can distinguish between usual leiomyomas and LMSs in most cases. 

On MRI, typical fibroid has well-defined borders,  whorled appearance and homogenous low signals on T2W imaging. While, leiomyosarcomas showed nodular borders, infiltrating myometrial mass with ill-defined margins, haemorrhage, heterogeneous signals  and central non-enhancing areas. In addition, raised serum lactate dehydrogenase isozymes level favours malignancy. 

Are you suffering from fibroids and want to understand if they are cancerous?

Consult our fibroid expert, Dr. Sandeep Burathoki, in Dubai

If you are struggling with fibroids and have concerns about their potential to be cancerous, Dr. Sandeep Buratokhi is here to provide expert guidance and support. With his extensive knowledge and experience, he can help you understand your condition better and guide you towards the most appropriate course of treatment. Don’t let fibroids affect your quality of life any longer – consult with Dr. Sandeep Buratokhi today to find relief from this common but often misunderstood condition.

Your health is important, so don’t hesitate to seek professional help when it comes to managing fibroids.

Consult with Dr. Sandeep