Liposarcoma: Types, Symptoms, and Causes

If you have liposarcoma, it means you have a type of cancer that grows in fat cells -- often on your limbs or your belly. It's one of a group of cancers that doctors call sarcomas, which start in soft tissues like muscles, tendons, and fat.

Liposarcoma can start in any area of fat in your body, but it usually grows in the upper leg, behind the knee, in the upper arm, or deep inside the belly. From there, it can spread to other parts of your body. Some liposarcomas grow faster and spread more quickly than others.

Types

There are five types of liposarcoma. Each one is based on how different the cancer cells look from healthy ones under a microscope and how quickly they grow.

Knowing which of these types you have will help your doctor find the right treatment.

Well-differentiated. This is the most common type of liposarcoma. It's usually found deep inside your body, often in the belly. The cancer cells are low-grade, which means they look a lot like normal fat cells under a microscope and grow slowly.

Myxoid. This type can grow faster than well-differentiated cancers. It often starts in the arms or legs.

Round cell. This type can also grow faster than well-differentiated tumors and is often found in the arms or legs.

Dedifferentiated. This happens when a slow-growing tumor changes into a faster-growing type. The new cells are high-grade, meaning they grow and spread quickly. Dedifferentiated liposarcoma starts deep in the belly.

Pleomorphic. It's the rarest type of liposarcoma. It grows quickly, and the cells look very different from normal cells under a microscope. It's found in the arms and legs.

Causes

Doctors don't know exactly what causes liposarcomas to grow. Like other cancers, changes to DNA allow cells to multiply out of control and form tumors.

Some things can raise the chances that you get liposarcoma. You may be more likely to get this cancer if you:

• Had radiation treatment for another type of cancer, such as breast cancer or lymphoma
• Are between ages 50 and 65
• Have an inherited condition such as neurofibromatosis, Werner syndrome, or Li-Fraumeni syndrome

Talk to your doctor about these risks. Just because you have one or more of them doesn't mean that you will get liposarcoma. This cancer is rare. And some people get liposarcoma without having any risks.