Fibrosarcoma is a very rare soft-tissue cancerous tumor, or sarcoma. If you develop fibrosarcoma, you have a soft tissue tumor in the tissues that wrap around your tendons, ligaments and muscles. There are two types of fibrosarcoma: infantile or congenital fibrosarcoma and adult-type fibrosarcoma. This article focuses on adult-type fibrosarcoma.


Fibrosarcoma as it may appear as a soft tissue tumor in tissues that wrap around your leg’s tendons, muscles and ligaments.
Fibrosarcoma in soft tissue that wraps leg muscle.

What is fibrosarcoma?

Fibrosarcoma is a very rare soft-tissue cancerous tumor, or sarcoma. Fibrous soft tissue is one of several soft tissues that keep your body together. Fibrous soft tissue is a connective tissue. Like its name, fibrous soft tissue connects parts of your body. For example, your tendons attach muscles to bones. Your ligaments attach bones to bones.

If you develop fibrosarcoma, you have a soft tissue tumor in the tissues that wrap around your tendons, ligaments and muscles. There are two types of fibrosarcoma: infantile or congenital fibrosarcoma and adult-type fibrosarcoma. This article focuses on adult-type fibrosarcoma.


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Who is affected by fibrosarcoma?

Fibrosarcoma is usually diagnosed in adults between the ages of 20 and 60. Men are slightly more likely than women to develop fibrosarcoma. Fibrosarcoma typically affects your thighs, knees, arms and trunk.

How does fibrosarcoma affect my body?

Because fibrosarcoma develops in deep soft tissues, you might not notice any changes in your body until the tumor grows bigger. You may notice a large fibrosarcoma tumor for the following reasons:

  • It's big enough for you to notice a new lump.
  • You feel pain because the tumor is pressing on nerves.
  • You have circulation issues because the tumor is pressing on blood vessels.


What is the survival rate for fibrosarcoma?

Between 40% and 60% of people who have fibrosarcoma are alive five years after diagnosis. Researchers are investigating several new ways to slow fibrosarcoma’s growth.

What are other soft tissue or bone cancers?

Other soft tissue or bone cancers include:

  • Chondrosarcoma: Chondrosarcoma is cancer of the cartilage. It's more common in adults.
  • Chordoma: This type of bone sarcoma typically starts in part of your spinal cord.
  • Ewing sarcoma:Ewing sarcoma, also known as Ewing’s sarcoma and Ewing tumor, is a rare bone and soft tissue cancer that affects children, teenagers and young adults.
  • Osteosarcoma:This is a bone tumor that usually develops at the end of your thigh, leg, arm and forearm. Osteosarcoma typically affects children, teenagers and young adults, but it sometimes affects older adults.
  • Undifferentiated pleomorphic sarcoma (UPS): UPS is an uncommon bone tumor, most closely related to osteosarcoma (see above). UPS of bone is usually found in adults. Common places for UPS to appear include your arm or leg, especially around your knee joint.


Symptoms and Causes

What are the symptoms of fibrosarcoma?

It takes time for fibrosarcoma symptoms to surface. And when they do, they can resemble symptoms of other, less serious conditions. Typical symptoms of fibrosarcoma include:

  • A painful soft lump.
  • Nerve compression (pinched nerve). You might feel tingling or “pins and needles” (paresthesia) or sharp, aching or burning pain.
  • Unusual swelling. This might be a sign your tumor is pressing on your blood vessels.
  • Unintended weight loss.

What causes fibrosarcoma?

Researchers haven’t pinpointed exactly what causes fibrosarcoma. But they have identified some inherited conditions that might increase your risk for developing fibrosarcoma:

Other potential risk factors are:

  • Previous radiation therapy.
  • Exposure to certain chemicals, such as thorium dioxide, vinyl chloride, or arsenic.
  • Lymphedema.

Diagnosis and Tests

How do healthcare providers diagnose fibrosarcoma?

First, providers will perform several tests. They’ll use what they learn to establish a stage and grade for your fibrosarcoma. Tests might include:

  • Magnetic resonance imaging (MRI):This is a painless test that uses a large magnet, radio waves and a computer to produce very clear images of organs and structures within your body.
  • Computed tomography scan (CT scan): CT scans use a series of X-rays and a computer to create three-dimensional images of your soft tissues and bones.
  • Core needle biopsy: Healthcare providers use a fine needle and syringe to extract fluid and tissue from lumps that appear abnormal.

What are cancer stages and grades?

Providers assign cancer grades based on what your tumor’s cells look like when viewed under a microscope. They look for changes in your cells and how closely your cells resemble normal or healthy cells.

Cancer cells that have few changes and look very similar to normal cells are low-grade cells. Cancer cells with many changes and that don’t look anything like normal cells are high-grade cells. The higher the cell grade, the more aggressive the tumor.

Cancer stages measures how far your cancer has spread. A small tumor found in just one area of your body is considered an early stage cancer. Cancer that’s spread throughout your body is a late-stage cancer.

Management and Treatment

Healthcare providers typically use a combination of surgery and radiation therapy to treat fibrosarcoma. They might also use chemotherapy.


How can I reduce my risk for fibrosarcoma?

You can reduce your risk for fibrosarcoma by understanding your family medical history. Fibrosarcoma appears to be related to some inherited conditions. If your family has a history of one of those conditions, you should ask your healthcare provider about monitoring your health for signs of fibrosarcoma so it can be diagnosed and treated early.

Outlook / Prognosis

What can I expect if I have fibrosarcoma?

Many fibrosarcoma tumors aren’t diagnosed until they have grown large enough to be noticeable soft lumps or affect your nerves or circulation. Like many types of cancer, early diagnosis can lead to more positive prognosis or expected outcome.

Between 40% and 60% of people treated for fibrosarcoma are alive five years after diagnosis. But researchers have identified treatments that could help slow the tumor’s growth and make the tumor more sensitive to chemotherapy.

Living With

How do I take care of myself if I have fibrosarcoma?

Many times cancer makes people feel as if they’ve lost control of their lives. Committing to self-care is one way to overcome those feelings. Here are some things you can do during and after your treatment for fibrosarcoma:

  • If you'll need cancer surgery, ask your healthcare provider what to expect immediately after surgery and any follow-up treatment. Knowing what to expect will help you focus on what you can control rather than what you can’t control.
  • Chemotherapy treatments might affect your appetite. Try to eat a healthy diet, and talk to a nutritionist if you're having trouble eating.
  • Radiation therapy can leave you feeling exhausted. Plan to rest as much as possible during your treatment.
  • You’ll probably need or want help while you’re going through treatment. Your friends and family likely are anxious to do what they can. Let them know how they can help you.
  • After treatment, you’ll have regular checkups and tests to see if your cancer has returned. That might make you feel as if you’re living from checkup to checkup and not able to live your life. Talk to your healthcare provider if you’re feeling anxious. They might have ideas for managing that anxiety.
  • Cancer is stressful. You might find that activities such as meditation, relaxation exercises or deep breathing exercises can help to ease your stress.

When should I see my healthcare provider if I have fibrosarcoma?

Generally speaking, you’ll see your provider every three months for the first two years after you finish treatment and then at longer intervals until four or five years after your treatment.

You should always contact your provider any time you notice new lumps or have new pain. Fibrosarcoma can come back after treatment or metastasize (spread to another area your body). While lumps and pain might not be cancer, you should see your provider so they can evaluate your symptoms.

When should I go to the emergency room?

Many cancer treatments affect your immune system, increasing your chance of developing infections. Symptoms that might require an emergency room visit during treatment include:

What questions should I ask my doctor?

Fibrosarcoma is a rare form of cancer. You might have questions about a cancer that few people know about. Here are basic questions you might want to ask your healthcare provider:

  • What kind of cancer is fibrosarcoma?
  • Why did I develop this cancer?
  • Can fibrosarcoma be cured?
  • What are treatment options for fibrosarcoma?
  • Will I have a single treatment or more than one kind of treatment?
  • What is the success rate for these treatments?
  • What are the side effects of each treatment?

A note from Cleveland Clinic

Learning you have a rare form cancer might launch a flood of emotions, from feeling afraid and anxious to feeling angry. Think about giving yourself some time to let those feelings flow. Doing that might help you to move on to next steps, such as helping your friends and family understand your diagnosis and how they can support you. If you’re feeling stuck or trapped in an emotional riptide, ask your healthcare provider for help. They understand what you’re going through and will be able to help you stay focused on your health.

Medically Reviewed

Last reviewed on 11/08/2021.

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