Leiomyosarcoma is a rare cancer that begins in smooth muscle tissue. Many areas of the body have smooth muscle tissue. Areas with smooth muscle tissue include the digestive system, urinary system, blood vessels and uterus.

Leiomyosarcoma most often starts in the smooth muscle tissue in the uterus, belly or leg. It starts as a growth of cells. It often grows quickly and can move to other parts of the body.

Symptoms of leiomyosarcoma depend on where the cancer starts. There may be no symptoms early in the condition.

Leiomyosarcoma is a type of soft tissue sarcoma. Soft tissue sarcoma is a broad group of cancers that begin in the connective tissues. Connective tissues connect, support and surround other body structures.

Symptoms

Leiomyosarcoma might not cause signs or symptoms at first. As the cancer grows, symptoms may include:

• Pain.
• Weight loss.
• Nausea and vomiting.
• A lump or swelling under the skin.

When to see a doctor

Make an appointment with a doctor or other healthcare professional if you have symptoms that worry you.

Causes

It's not clear what causes leiomyosarcoma. This cancer starts when something changes the cells in the smooth muscles. Many areas of the body have smooth muscle tissue. These include the digestive system, urinary system, blood vessels and uterus.

Leiomyosarcoma happens when smooth muscle cells develop changes in their DNA. A cell's DNA holds the instructions that tell the cell what to do. In healthy cells, the DNA tells the cells to grow and multiply at a set rate. The DNA also tells the cells to die at a set time.

In cancer cells, the DNA changes give other instructions. The changes tell the cancer cells to grow and multiply at a fast rate. Cancer cells can keep living when healthy cells would die. This causes too many cells.

The cancer cells might form a mass called a tumor. The tumor can grow to invade and destroy healthy body tissue. In time, cancer cells can break away and spread to other parts of the body. When cancer spreads, it's called metastatic cancer.

Risk factors

Risk factors for leiomyosarcoma include:

• Being an adult. Leiomyosarcoma can happen at any age. But it is most common in adults. It's rare in children.
• Having certain genetic conditions. People with certain genetic conditions may have a higher risk of leiomyosarcoma. These conditions include hereditary retinoblastoma and Li-Fraumeni syndrome.

Healthcare professionals haven't found a way to prevent leiomyosarcoma.

Diagnosis

To diagnose leiomyosarcoma, a healthcare professional might start with a physical exam to understand your symptoms. Other tests and procedures used to diagnose leiomyosarcoma include imaging tests and a biopsy.

Physical exam

A healthcare professional might ask about your symptoms and your health history. The health professional may examine your body to look for areas of swelling or lumps under the skin.

Imaging tests

Imaging tests make pictures of the inside of the body. The pictures can help your healthcare team understand the size of leiomyosarcoma and where it is. Imaging tests might include:

• MRI.
• CT scan.
• Positron emission tomography scan, also called PET scan.

Biopsy

A biopsy is a procedure to remove a sample of tissue for testing in a lab. How a healthcare professional collects the biopsy sample depends on where the affected tissue is. For leiomyosarcoma, the biopsy is often collected with a needle. The healthcare professional puts the needle through the skin to get the sample.

The sample goes to a lab for testing. Results can show whether there is cancer.

A biopsy for leiomyosarcoma needs to be done in a way that won't cause problems with future surgery. For this reason, it's a good idea to seek care at a medical center that sees many people with this type of cancer. Experienced healthcare teams will select the best type of biopsy.

Treatment

Treatment of leiomyosarcoma depends on where the cancer is, how big it is and whether it has spread to other areas of the body. Your overall health and what you want also are part of the treatment plan.

Surgery

The goal of surgery is to remove all the leiomyosarcoma. But that might not be possible if the cancer is large or involves nearby organs. Then your surgeon may remove as much of the cancer as possible.

Radiation therapy

Radiation therapy treats cancer with powerful energy beams. The energy can come from X-rays, protons or other sources.

Radiation therapy can be used before, after or during surgery. It can treat cancer cells that can't be removed during surgery. Radiation therapy also might be used when surgery isn't an option.

Chemotherapy

Chemotherapy treats cancer with strong medicines. Most chemotherapy medicines are given through a vein.

Healthcare professionals might suggest chemotherapy to prevent the leiomyosarcoma from returning after surgery. It also might be used to control cancer that spreads to other areas of the body.

Targeted therapy

Targeted therapy for cancer is a treatment that uses medicines that attack specific chemicals in the cancer cells. By blocking these chemicals, targeted treatments can cause cancer cells to die.

Targeted therapy may be an option for leiomyosarcoma that grows large or spreads to other parts of the body. Your healthcare professional may test your cancer cells to see if targeted medicines might help you.

Coping and support

With time, you'll find things that help you cope with your cancer diagnosis. Until then, you may find that it helps to:

Learn enough about your cancer to make decisions about your care

Ask your healthcare team about your cancer. Also ask about your test results, treatment options and, if you like, your outlook, called prognosis. Knowing more about your cancer and your treatment choices may help you make decisions about your care.

Keep friends and family close

Keeping your close relationships strong can help you deal with your cancer. Friends and family can give you the support you need, such as helping take care of your home if you're in the hospital. They can serve as emotional support when you feel overwhelmed by cancer.

Find someone to talk with

Find a good listener who is willing to hear you talk about your hopes and fears. This may be a friend or family member. The concern and understanding of a counselor, medical social worker, clergy member or cancer support group also may be helpful.

Ask your healthcare team about support groups in your area. In the United States, other sources of information include the National Cancer Institute and the American Cancer Society.

Preparing for an appointment

Start by making an appointment with a doctor or other healthcare professional if you have symptoms that worry you.

If your healthcare professional thinks that you may have leiomyosarcoma, you may be sent to a specialist. Often the specialist is a doctor who treats cancer, called an oncologist.

Here's some information to help you get ready for your appointment.

What you can do

• Find out what to do before your appointment. When you make the appointment, ask if there's anything you need to do in advance, such as restrict your diet.
• Write down your symptoms, including any that may not seem linked to the reason for your appointment, and when they began.
• Write down key personal information, including any major stresses or recent life changes.
• Make a list of all medicines, vitamins or supplements you take, including doses.
• Ask a family member or friend to go with you. Someone who's with you can help you remember the information you get.
• Write down questions to ask your healthcare professional.

For leiomyosarcoma, some basic questions to ask include:

• Has my cancer spread?
• Will I need more tests?
• What treatments are there for my leiomyosarcoma?
• What are the benefits and risks of each treatment?
• Is there one treatment you suggest over the others?
• Are there brochures or other printed materials that I can have? What websites do you suggest?

Be sure to ask all the questions you have.

What to expect from your doctor

Your healthcare team is likely to ask you questions, including:

• Have your symptoms been constant or do they come and go?
• How bad are your symptoms?
• What, if anything, seems to make your symptoms better?
• What, if anything, appears to make your symptoms worse?