Leiomyosarcoma (LMS) is a type of soft tissue sarcoma.
We hope this information answers your questions. If you have any further questions, you can ask your doctor or nurse at the hospital where you're having your treatment.
Leiomyosarcoma belongs to a group of cancers called soft tissue sarcomas. Sarcomas are cancers that develop in the supporting or connective tissues of the body, such as muscle, fat, nerves, blood vessels, bone, and cartilage. Soft tissue sarcomas are rare. Approximately 1 out of 100 (1%) of all cancers are soft tissue sarcomas. Most people with leiomyosarcoma are over the age of 50.
Leiomyosarcomas are one of the more common types of sarcoma to develop in adults. They start from cells in a type of muscle tissue called smooth muscle.
Smooth muscles are involuntary muscles that we have no control over. They are found in the walls of muscular organs like the heart and stomach, as well as in the walls of blood vessels throughout the body.
This means that leiomyosarcomas can start anywhere in the body. Common places are the walls of the womb (uterus), the limbs and the digestive system - particularly the stomach.
Causes of leiomyosarcoma
Back to top
The exact causes of leiomyosarcoma are not known, and research is ongoing to try to find out as much as possible about them.
Very rarely, soft tissue sarcomas may occur in an area that has previously been treated with radiotherapy for another type of cancer. The sarcoma won’t usually develop until about 10 years after the radiotherapy treatment.
Exposure to some types of chemicals may increase the risk of developing some sarcomas. The chemicals include vinyl chloride (used for making plastics), some types of herbicides (weedkillers) and dioxins.
Signs and symptoms of leiomyosarcoma
Back to top
People with early leiomyosarcoma often don’t have any symptoms. Most leiomyosarcomas are diagnosed after a person develops symptoms. These may include:
a lump or swelling
abdominal discomfort or bloatedness
swelling or pain in any area of the body
bleeding from the vagina in women who have had the menopause, or a change in periods for women who have not yet had the menopause.
If you notice any of the above, you should contact your GP, but remember that these symptoms can also be caused by many other things.
How leiomyosarcoma is diagnosed
Back to top
Usually you begin by seeing your family doctor (GP), who will examine you. You will be referred to a hospital specialist for any tests that may be necessary and for expert advice and treatment. The doctor at the hospital will take your full medical history, do a physical examination and take blood samples to check your general health.
The following tests are commonly used to diagnose a leiomyosarcoma. The tests you have will depend on the part of the body being investigated. You may have had some of these tests already. If you’re having investigations other than those listed, our cancer support specialists can give you further information.
This is the most common test used to diagnose problems in the stomach and oesophagus (gullet). Before an endoscopy, your stomach has to be empty so you will be asked not to eat or drink anything for at least four hours beforehand. Once you're lying comfortably on the couch, you will usually be given a sedative to make you feel sleepy and reduce any discomfort during the test. This is generally injected into a vein in your arm. A local anaesthetic is then sprayed onto the back of your throat and the doctor passes an endoscope (a flexible tube with a light and lens at the end) down the gullet into the stomach.
Photographs are taken of the stomach and a small sample of cells (a biopsy) can be taken for examination under a microscope. Sometimes the endoscopy tube has an ultrasound probe at the end, which allows an ultrasound scan to be taken of the stomach and surrounding structures. This is known as endoscopic ultrasound.
An endoscopy can be uncomfortable, but it is not painful. After a few hours, the effects of the sedative should have worn off and you will be able to go home. You should not drive for several hours afterwards and it's a good idea to arrange for someone to travel home with you. Some people have a sore throat after their endoscopy. This should disappear after a couple of days.
This test is used to diagnose problems in the womb. The doctor uses a small, thin tube with a light and camera at the end (hysteroscope) to look into the womb and take tissue samples to be looked at under a microscope. The hysteroscope is passed through your vagina and into your womb. You may have this test as an outpatient under local anaesthetic, but sometimes a general anaesthetic is needed.
A hysteroscopy may be uncomfortable but should not be painful. Some women may have mild cramping during the procedure and for a few days afterwards.
This test uses sound waves to make up a picture of the abdomen and surrounding organs. It is done in the hospital's scanning department. You will be asked not to eat, and to only drink clear fluids (nothing fizzy or milky) for 4-6 hours before the scan. Once you’re lying comfortably on your back, a gel is spread over your abdomen. A small device like a microphone (called a probe) is then rubbed over the area. It emits sound waves that are then converted into a picture using a computer. Sometimes the probe is inserted gently into the vagina to examine the womb more closely. The test should not be painful and takes about 15-20 minutes.
CT (computerised tomography) scan
A CT scan takes a series of x-rays that build up a three-dimensional picture of the inside of the body. The scan is painless and takes 10-30 minutes. CT scans use small amounts of radiation, which is very unlikely to harm you or anyone you come into contact with. You will be asked not to eat or drink for at least four hours before the scan.
You may be given a drink or an injection of dye that allows particular areas to be seen more clearly. This may make you feel hot all over for a few minutes. If you’re allergic to iodine or have asthma, you could have a more serious reaction to the dye, so it’s important to let your doctor know beforehand.
You will probably be able to go home as soon as the scan is over.
MRI (magnetic resonance imaging) scan
This test is similar to a CT scan but uses magnetism instead of x-rays to build up cross-sectional pictures of your body. During the test, you’ll be asked to lie very still on a couch inside a large metal cylinder that is open at both ends. The whole test may take up to an hour. It can be slightly uncomfortable and some people feel a bit claustrophobic during the scan. It’s also very noisy, but you will be given earplugs or headphones to wear. You will be able to hear, and speak to, the person operating the scanner.
If you have any metal implants such as certain types of surgical clips, pacemakers or metal in the eye from previous accidents or trauma; it will not be possible for you to have this test.
The results of the previous tests may make your doctor strongly suspect you have cancer. The only way to be sure is to take some cells or a small piece of tissue from the affected area to look at under a microscope. This is called a biopsy. A fine needle is passed into the tumour through the skin after the area has been numbed using a local anaesthetic injection. A CT or ultrasound scan may be used at the same time to make sure that the biopsy is taken from the right place.
When the cells are looked at under a microscope, the specialist will be able to tell whether they are benign (not cancerous) or malignant (cancerous). If a sarcoma is diagnosed, further tests may be done on the sample to try to find out exactly what type of sarcoma it is.
Grading and staging of leiomyosarcoma
Back to top
Grading refers to the appearance of cancer cells under a microscope. The grade gives an idea of how quickly a cancer may develop.
Grading of soft tissue sarcomas can sometimes be difficult, especially for the less common types.
Low-grade means that the cancer cells look very much like the normal cells of the soft tissues. They are usually slow-growing and are less likely to spread. In high-grade tumours the cells look very abnormal. They are likely to grow more quickly and are more likely to spread.
The stage of a cancer is a term used to describe its size and whether it has spread beyond its original site. Knowing the particular type and the stage of the cancer helps the doctors decide on the most appropriate treatment.
The following is a commonly used staging system for non-gynaecological leiomyosarcoma. A different system is used for leiomyosarcoma arising in the gynaecological organs. Your specialist can explain more if you have this type of leiomyosarcoma.
The tumour is low-grade and small (less than 5cm [2in]). It can be near the surface of the body (superficial) or deep within the body, but with no sign that it has spread to the lymph nodes or other parts of the body.
The tumour is low-grade and large (more than 5cm [2in]). It’s superficial with no sign that it has spread to the lymph nodes or other parts of the body.
The tumour is low-grade and large (more than 5cm [2in]). It’s deep within the body but has not spread to the lymph nodes or other parts of the body.
The tumour is high-grade and small (less than 5cm [2in]). It can be near the surface of the body or deep within the body, but has not spread to the lymph nodes or other parts of the body.
The tumour is high-grade, large (more than 5cm [2in]) and superficial, but has not spread to the lymph nodes or other parts of the body.
The tumour is high-grade, large (more than 5cm [2in]) and deep, but has not spread to the lymph nodes or other parts of the body.
The tumour has spread to lymph nodes in the area or to any other part of the body. This is known as secondary or metastatic soft tissue sarcoma.
This means that a soft tissue sarcoma has come back after it was first treated. It may come back in the tissues where it first started (local recurrence) or in another part of the body (metastasis).
Treatment for leiomyosarcoma
Back to top
The treatment for leiomyosarcoma depends on a number of things, including your general health and the size and position of the tumour within the body. The results of your tests will help your doctor decide on the best type of treatment for you. They can then discuss this with you.
The usual treatment for a leiomyosarcoma is surgery, wherever possible, to remove the tumour. This may be followed by radiotherapy to reduce the chance of the cancer coming back.
Chemotherapy is also used for some leiomyosarcomas. This may be to try to reduce the chances of the leiomyosarcoma coming back, or to treat a leiomyosarcoma that has spread.
Treatment of sarcomas is discussed in more detail in our general information about soft tissue sarcomas.
Clinical trials for leiomyosarcoma
Back to top
Research into treatments for leiomyosarcoma is ongoing and advances are being made. Cancer doctors use clinical trials to assess new treatments.
Before any trial is allowed to take place, it must be approved by an ethics committee, which protects the interests of the patients taking part.
You may be asked to take part in a clinical trial. If you decide to take part, your doctor will discuss the treatment with you so that you have a full understanding of the trial and what it means to take part. You may decide not to take part or withdraw from a trial at any stage. You’ll still receive the best standard treatment available.
Your feelings about leiomyosarcoma
Back to top
You may have many different emotions including anger, resentment, guilt, anxiety and fear. These are all normal reactions, and are part of the process many people go through in trying to come to terms with their condition.
Everyone has their own way of coping with difficult situations. Some people find it helpful to talk to family or friends, while others prefer to seek help from people outside their situation. Some people prefer to keep their feelings to themselves. There is no right or wrong way to cope, but help is there if you need it. Our cancer support specialists can give you information about counselling in your area.
Rarer Cancers Foundation
Rarer Cancers Foundation (RCF) is a UK charity that offers general advice and information about rare and less common cancers, facilitates supportive networking between patients and carers, and works to improve services for people with rarer cancers.
is an alliance of more than 50 organisations working to address the inequalities that exist in policy, services and research into the less common cancers and to improve outcomes for patients with these highly challenging diseases.
Sarcoma UK provides information and support to anyone affected by sarcoma, and aims to achieve the best possible standard of treatment and care for patients with sarcoma.
This information has been compiled using a number of reliable sources, including:
Raghavan, D. et al. Textbook of Uncommon Cancers. 3rd edition. 2006. Wiley. West Sussex.
Improving outcomes for people with sarcoma. March 2006. National Institute for Health and Clinical Excellence (NICE).
Weiss, S. et al. Enzinger and Weiss's Soft Tissue Tumors. 5th edition. 2008. Mosby. Philadelphia.
Thank you to Professor D Luesley, Gynaecological Oncologist, and all the people affected by cancer who reviewed this information. Reviewing information is just one of the ways you could help when you join our Cancer Voices network.