Liposarcoma is a rare type of cancer that begins in the fat cells. Liposarcoma is considered a type of soft tissue sarcoma.

Liposarcoma can occur in fat cells in any part of the body, but most cases occur in the muscles of the limbs or in the abdomen. Liposarcoma occurs most often in older adults, though it can occur at any age.

Treatment for liposarcoma typically involves surgery to remove the cancer. Other treatments, such as radiation therapy, also may be used.

Liposarcoma signs and symptoms vary depending on the part of the body where the cancer forms.

Liposarcoma that forms in the arms and legs can cause:

• A growing lump of tissue under your skin
• Pain
• Swelling
• Weakness of the affected limb

Liposarcoma that forms in the abdomen can cause:

• Abdominal pain
• Abdominal swelling
• Feeling full sooner when eating
• Constipation
• Blood in stool

When to see a doctor

Make an appointment with your doctor if you have any persistent signs or symptoms that worry you.

It's not clear what causes liposarcoma.

Doctors know that liposarcoma forms when a fat cell develops errors (mutations) in its genetic code. The mutations tell the cell to multiply rapidly and to go on living when other cells would die. The accumulating abnormal cells form a mass (tumor).

Several types of liposarcoma exist. Some grow slowly and the cells stay in one area of the body. Other types grow very quickly and may spread to other areas of the body.

Tests and procedures used in liposarcoma diagnosis include:

• Imaging tests. Your doctor may recommend imaging tests to determine the size and extent of your liposarcoma. Tests may include X-ray, CT scan and MRI.
• Removing a sample of tissue for testing. During a biopsy procedure, your doctor removes a small sample of tissue to test for cancer cells. Your tumor's location determines how the tissue sample is removed.
• Using advanced lab tests to determine the kinds of cells involved in the cancer. Doctors who specialize in analyzing blood and body tissue (pathologists) will study your biopsy samples using specialized laboratory tests, such as immunohistochemistry, cytogenetic analysis, fluorescence in situ hybridization and molecular genetic testing. These tests provide information about your liposarcoma that helps your doctor determine your prognosis and your treatment options.

Treatments for liposarcoma include:

• Surgery. The goal of surgery is to remove all of the cancer cells. Whenever possible, surgeons work to remove the entire liposarcoma.

  If a liposarcoma grows to involve nearby organs, removal of the entire liposarcoma may not be possible. In those situations, your doctor may recommend other treatments to shrink the liposarcoma to make it easier to remove during an operation.

• Radiation therapy. Radiation therapy uses powerful energy beams, such as X-rays and protons, to kill cancer cells. Radiation may be used after surgery to kill any cancer cells that remain. Radiation may also be used before surgery to shrink a tumor in order to make it more likely that surgeons can remove the entire tumor.

• Chemotherapy. Chemotherapy uses drugs to kill cancer cells. Not all types of liposarcoma are sensitive to chemotherapy drugs. Careful analysis of your cancer cells by an expert pathologist can determine whether chemotherapy is likely to help you.

  Chemotherapy may be used after surgery to kill any cancer cells that remain or before surgery to shrink a tumor. Chemotherapy is sometimes combined with radiation therapy.

• Clinical trials. Clinical trials are studies of new treatments. Clinical trials might give you a chance to try the latest treatments, such as new types of chemotherapy and targeted therapy drugs. Ask your doctor whether you qualify for any clinical trials.

Start by first seeing your family doctor or health care provider if you have any signs or symptoms that worry you. If you're diagnosed with liposarcoma, you'll be referred to a doctor who specializes in treating cancer (oncologist).

Because appointments can be brief, and because there's often a lot of ground to cover, it's a good idea to be prepared. Here's some information to help you get ready, and what to expect from your doctor.

What you can do

• Be aware of any pre-appointment restrictions. At the time you make the appointment, ask if there's anything you need to do in advance, such as restrict your diet.
• Write down any symptoms you're experiencing, including any that may seem unrelated to the reason for which you scheduled the appointment.
• Write down key personal information, including any major stresses or recent life changes.
• Make a list of all medications, vitamins or supplements that you're taking.
• Consider taking a family member or friend along. Sometimes it can be difficult to remember all the information provided during an appointment. Someone who accompanies you may remember something that you missed or forgot.
• Write down questions to ask your doctor.

Your time with your doctor is limited, so preparing a list of questions can help you make the most of your time together. List your questions from most important to least important in case time runs out. For liposarcoma, some basic questions to ask your doctor include:

• Do I have cancer?
• Do I need more tests?
• Can I have a copy of my pathology report?
• What are my treatment options?
• What are the potential risks of each treatment option?
• Can any treatments cure my cancer?
• Is there one treatment you feel is best for me?
• If you had a friend or family member in my situation, what would you recommend?
• How much time can I take to choose a treatment?
• How will cancer treatment affect my daily life?
• Should I see a specialist? What will that cost, and will my insurance cover it?
• Are there brochures or other printed material that I can take with me? What websites do you recommend?

In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask other questions during your appointment.

What to expect from your doctor

Your doctor is likely to ask you a number of questions. Being ready to answer them may allow more time later to cover other points you want to address. Your doctor may ask:

• When did you first begin experiencing symptoms?
• Have your symptoms been continuous or occasional?
• How severe are your symptoms?
• What, if anything, seems to improve your symptoms?
• What, if anything, appears to worsen your symptoms?