Leiomyosarcoma is a rare cancer that grows in the smooth muscles, like those found in your stomach, bladder, uterus, intestines and blood vessels. Treatments may include chemotherapy, radiation therapy or surgery.


Medical illustration example of a Leiomyosarcoma affecting a kidney.
Very rarely, leiomyosarcoma can affect the kidneys.

What is leiomyosarcoma?

Leiomyosarcoma (LMS) is an aggressive, rare type of cancer that forms in smooth, involuntary muscles. Smooth muscles are distinct from skeletal muscles, which we use to move our bodies. Smooth muscle tissue can be found in several areas of your body, including your urinary system, digestive system, uterus and blood vessels. Leiomyosarcoma is considered a soft tissue sarcoma.


Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy

What are the different types of leiomyosarcoma?

There are three different types of leiomyosarcoma. These include:

  • Somatic soft tissue LMS. This type of leiomyosarcoma affects your body’s connective tissue. It’s the most common form of LMS.
  • Cutaneous or subcutaneous LMS. A rare type of leiomyosarcoma, cutaneous or subcutaneous LMS affects the piloerector muscles in the skin. (The piloerector muscles are located in your skin and eyes. They’re responsible for giving you goosebumps and making your pupils dilate.)
  • LMS of a vascular origin. The rarest type of leiomyosarcoma, LMS of a vascular origin develops in a major blood vessel, such as the pulmonary artery, inferior vena cava or peripheral arteries.

Who does leiomyosarcoma affect?

Leiomyosarcoma affects men and women, but it occurs more often in women. Though the condition can develop in people of any age, it’s more common in people over the age of 50.


How common is leiomyosarcoma?

According to the American Cancer Society, approximately 15,000 people are diagnosed with soft tissue sarcoma every year. Leiomyosarcoma accounts for 10% to 20% of those cases. In the United States, there are about 1.4 leiomyosarcoma cases for every 100,000 people.

How fast does leiomyosarcoma grow?

Leiomyosarcoma is aggressive. It grows quickly and can double in size in as little as one month. For this reason, prompt treatment is necessary.


What’s the difference between leiomyosarcoma and leiomyoma?

Leiomyomas are benign (non-cancerous) fibroids that occur in the smooth muscles. While they can be problematic, leiomyomas don't spread to other areas of the body. However, leiomyosarcomas are cancer and can spread throughout the body.

Symptoms and Causes

What are the symptoms of leiomyosarcoma?

People may have varying symptoms depending on how big the tumor is and where it’s located. Some people don’t experience symptoms early on, but may notice certain signs as the tumor grows, such as:

Leiomyosarcoma in your digestive system may cause:

Uterine leiomyosarcoma can cause:

What causes leiomyosarcoma?

Experts aren’t exactly sure what causes leiomyosarcoma. It could be hereditary (meaning you inherited altered genes from your parents), or it could be because your own genes changed, causing cells to grow out of control. Leiomyosarcoma may also occur due to:

  • Past radiation therapy.
  • Exposure to certain chemicals, such as weed killers and pesticides.

How does leiomyosarcoma spread?

Leiomyosarcoma travels through your bloodstream. The cancer can then spread to any soft tissue in your body including your lungs.

Diagnosis and Tests

How is leiomyosarcoma diagnosed?

If you have symptoms concerning for leiomyosarcoma, you healthcare provider will order some tests. These may include:

Management and Treatment

How is leiomyosarcoma treated?

Leiomyosarcoma treatment depends on the location and size of the tumor. Your healthcare provider may recommend:

  • Surgery. When surgery is possible, it’s the best treatment option for leiomyosarcoma. The goal is to remove the entire tumor so that the cancer doesn’t come back.
  • Chemotherapy. This treatment is often recommended when the tumor is large, or when cancer cells have spread to other parts of the body.
  • Radiation therapy. This treatment may be used before surgery to shrink the tumor or after surgery to kill any remaining cancer cells.

Are there side effects of leiomyosarcoma treatment?

People who are undergoing leiomyosarcoma treatment may experience side effects. Specific side effects depend on the type of treatment you receive:



Radiation therapy

  • Tiredness.
  • Dry or itchy skin.
  • Nausea.

How long does it take to recover from leiomyosarcoma treatment?

Recovery times can vary drastically depending on several factors, including which type of treatment you receive and your body’s healing capacity. It could take several weeks to several months to fully recover. Even after you’re feeling better, you’ll still need regular checkups to monitor your health and reduce the risk of cancer returning.


Can leiomyosarcoma be prevented?

Currently, there’s no known way to prevent leiomyosarcoma. But you can reduce your risk by avoiding risk factors whenever possible. Known leiomyosarcoma risk factors include:

  • Radiation exposure.
  • Certain viral infections, such as human herpesvirus 8 (HHV8).
  • Tamoxifen (commonly used to treat breast cancer).

Outlook / Prognosis

Can leiomyosarcoma be cured?

Yes. Leiomyosarcoma can be cured, especially when detected and treated early on. If discovered in the later stages, treatment is more complicated.

Why is leiomyosarcoma so deadly?

Leiomyosarcoma can spread quickly because it’s hard to detect in the early stages. Sometimes symptoms don’t occur until the disease has progressed. However, if leiomyosarcoma is detected and treated in the early stages, full recovery is possible.

Living With

When should I see my healthcare provider?

If you’re undergoing treatment for leiomyosarcoma, call your healthcare provider at the first sign of troubling symptoms. For example, if you notice any changes to your tumor — or if you develop severe pain, sudden weight changes or other symptoms — prompt care is needed.

What questions should I ask my healthcare provider?

If you’ve been diagnosed with leiomyosarcoma, it’s important to talk with your healthcare provider about your treatment process. This can empower you and help you take control of your health. Here are some questions you may want to ask:

  • Where is my cancer located?
  • Has my cancer spread?
  • How advanced is my cancer?
  • What are my treatment options?
  • What are the risks and side effects of treatment?
  • What are the chances that my cancer will come back after treatment?
  • What is my outlook?

A note from Cleveland Clinic

Being diagnosed with any type of cancer can be scary, saddening and even frustrating. Fortunately, there are resources that can help. In addition to talking with your medical team, you may want to consider joining a support group for people with leiomyosarcoma. Talking with others who are going through the same thing can be an invaluable benefit as you begin your journey.

Medically Reviewed

Last reviewed on 11/08/2021.

Learn more about our editorial process.

Cancer Answer Line 866.223.8100