Leiomyosarcoma | Sarcoma UK
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Leiomyosarcoma develops in the smooth muscle cells, which are sometimes called involuntary muscles because they cause organs to contract without our control.

They are most commonly found in the limbs, the tummy (abdomen), the uterus, and the retroperitoneum (which is found deep in the abdomen and pelvis, behind the abdominal lining).

Leiomyosarcoma mostly affects adults and is very rare in people under 20 years of age.

There are two main types of leiomyosarcoma:

  • Uterine leiomyosarcoma
  • Soft tissue leiomyosarcoma (or non-uterine leiomyosarcoma)

Uterine leiomyosarcomas are leiomyosarcomas that originate in the uterus (also known as the womb).

Soft tissue leiomyosarcomas are leiomyosarcomas that can originate in the soft tissues of the limbs, the tummy (abdomen), and the retroperitoneum (the area in the back of the tummy).


There are an average of 525 cases of leiomyosarcoma diagnosed every year in England.

Leiomyosarcoma makes up 11.8% of all soft tissue sarcomas, and about 0.17% of all cancers.

Although leiomyosarcoma can affect anyone of any age, the median age at diagnosis is 64 years old.

There are more females diagnosed with leiomyosarcoma. This is because they can be diagnosed with uterine leiomyosarcoma, which is a subtype of leiomyosarcoma.

For more information on these statistics, you can visit our soft tissue sarcoma data hub.

Signs and symptoms

Symptoms of leiomyosarcoma can vary depending on the size and location of your tumour. You may experience all, some, or none of these symptoms before you are diagnosed with leiomyosarcoma:

A lump or swelling in the soft tissue of the body under the skin, often on the arm, leg, or trunk, that is:

  • increasing in size
  • is larger than 5cm
  • usually painful, but not always

For uterine leiomyosarcoma, symptoms may also include:

  • vaginal bleeding post-menopause
  • vaginal bleeding between periods
  • vaginal bleeding that feels unusual to you
  • pain around the pelvis or stomach


Diagnosing soft tissue leiomyosarcoma

Leiomyosarcomas are usually found by a patient when a lump appears on the leg, arm or trunk. They can also be found during an investigation of other symptoms or during a routine operation.

A specialist doctor will diagnose leiomyosarcoma through a series of tests. These may include:

  • Physical examination – looking at and feeling any lump
  • A scan – taking pictures of the inside of the body using ultrasound, x-ray, CT, EUS, PET or MRI
  • A biopsy – taking and testing a tissue sample

Diagnosing uterine leiomyosarcoma

You may have a hysteroscopy, which is a procedure used to examine and diagnose problems in the uterus.

Alongside a hysteroscopy, you may also have:

  • A pelvic ultrasound
  • An endometrial biopsy

Uterine leiomyosarcomas can often be misdiagnosed as benign fibroids. If the fibroids continue to grow in size after menopause, you should be seen for further examination.

To read more about scans and tests, click here.



Surgery is the most common treatment method for patients with leiomyosarcoma, regardless of subtype, and especially if the cancer has not spread. For uterine leiomyosarcoma, a hysterectomy (which is a surgical procedure to remove the uterus) is often recommended if the cancer is limited to the uterus and has not spread.


Radiotherapy may also be offered if the leiomyosarcoma is located in either a limb or in the trunk.

It can be offered either before or after surgery to reduce the risk of your cancer recurring. Radiotherapy can also be offered if surgery is not possible or if the tumour cannot be completely removed.

Recent studies have shown that in leiomyosarcomas that are located in the retroperitoneum, radiotherapy may not add any benefit to surgery alone.

Studies have shown that radiotherapy is not effective in uterine leiomyosarcomas following surgery, but may be useful for inoperable tumours to help with symptoms (such as pain or bleeding).


There is limited data on the role of chemotherapy in treating soft tissue and uterine leiomyosarcoma. This means that the effectiveness of chemotherapy on leiomyosarcoma that has not spread is yet to be fully understood.

There is potentially a role for chemotherapy if the cancer has spread, if surgery is not possible or if the tumour cannot be completely removed.

Clinical trials

You may be offered an opportunity to take part in a study to investigate new diagnosis methods or treatments. Some studies also look at the care and wellbeing of patients. Your doctor or nurse can give you more information on opportunities for you to take part in a clinical trial. You can also take a look at our Clinical Trials Hub.

After treatment

After treatment, you will have regular follow-up appointments for several years. You should receive a follow-up schedule from your sarcoma clinical nurse specialist. The usual practice will include:

  • A chance to discuss symptoms
  • An examination to look for any signs of the sarcoma returning. This may include an MRI or ultrasound if required after examination
  • A chest x-ray to rule out any secondary cancers occurring in the lungs

Living with

Leiomyosarcoma can reappear in the same area after the treatment of a previous tumour; this is called a local recurrence.

If the cancer does reappear, it is important to get treated as quickly as possible. This could involve further surgery and/or radiotherapy; your treatment will be assessed on an individual basis. Your multidisciplinary team will work closely with each other and with you to provide support and involve you in discussing all the possible treatment options.

It is useful to check for recurrences yourself through self-examination: your doctor or sarcoma clinical nurse specialist can tell you what to look for.

If you experience any new symptoms or changes in your health, contact your clinical team; they may decide to bring forward the date of your follow up appointment to investigate your concerns.

What if my cancer spreads to another part of my body?

A recurrence of sarcoma may be accompanied by cancer in other parts of the body. This is called metastasis or secondary cancer. Some people are diagnosed with sarcoma because their metastases have been discovered before their primary sarcoma tumour.

Your treatment will be assessed on an individual basis.

Survival statistics

If you or a loved one has been diagnosed with sarcoma, you may be feeling scared and uncertain about the future. However, it’s important to remember that there is hope, and that many people with sarcoma are able to live long, fulfilling lives after their diagnosis.

Survival depends on a number of different factors. Doctors usually use large sets of data to determine the outlook for a particular type of cancer. However, sarcoma is rare, which means survival is harder to estimate than for other, more common cancers.

Here are some survival statistics for leiomyosarcoma:

  • 90% of males and 79% of females diagnosed with leiomyosarcoma in England survive their disease for one year or more (2013-2017).
  • 72% of males and 45% of females diagnosed with leiomyosarcoma in England survive their disease for five years or more (2013-2017).

This split is due to the number of cases of uterine leiomyosarcoma that are diagnosed in females.

It’s important to keep in mind that survival rates are just one factor to consider when it comes to your prognosis. Your individual prognosis will depend on many factors, including your age, overall health, and the stage and grade of your cancer.

About these statistics

The terms 1 year survival and 5 year survival don’t mean that you will only live for 1 or 5 years.

The Office for National Statistics (ONS) and researchers collect information. They watch what happens to people with cancer in the years after their diagnosis. 5 years is a common time point to measure survival. But some people live much longer than this.

5 year survival is the number of people who have not died from their cancer within 5 years after diagnosis.

If you have any questions or if you need to talk to someone, our Support Line team are here for you.


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