Myxofibrosarcoma is a type of cancer that begins in the connective tissue. It tends to happen in the arms and legs.

Myxofibrosarcoma starts as a growth of cells that can grow into healthy body tissue. Myxofibrosarcoma might cause a lump under the skin that grows slowly. It often isn't painful. This cancer happens most often in older adults.

Myxofibrosarcoma is a type of soft tissue sarcoma. Soft tissue sarcomas are cancers that happen in the soft tissues that connect, support and surround other body structures.

Symptoms

Symptoms of myxofibrosarcoma include:

• A painless lump on an arm or leg.
• A lump that grows slowly.

Myxofibrosarcoma most often starts in the leg. It rarely starts in the abdomen, where other kinds of sarcomas tend to grow.

When to see a doctor

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

Causes

The cause of myxofibrosarcoma often isn't known. This cancer starts as a growth of cells in the connective tissue.

Myxofibrosarcoma happens when 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 gives instructions to grow and multiply at a set rate. The instructions tell the cells to die at a set time.

In cancer cells, the DNA changes give different instructions. The changes tell the cancer cells to grow and multiply quickly. Cancer cells can keep living when healthy cells would die. This causes too many cells. The cancer cells can form a lump that may grow into healthy body tissue.

Risk factors

The risk of myxofibrosarcoma is higher in adults. This cancer happens most often in adults ages 50 to 70. It is rare in people under age 30.

There is no way to prevent myxofibrosarcoma.

Diagnosis

Tests and procedures used to diagnose myxofibrosarcoma include:

• Physical exam. Your healthcare professional may ask about your symptoms and health. The health professional may check your body for signs of cancer.
• Imaging tests. Imaging tests make pictures of the body. The pictures might help your healthcare professional learn more about the cancer and its size. One test used for this purpose is MRI, which can look closely at the soft tissue, bone and muscle. You might have other imaging tests to look for signs that the cancer has spread to other parts of the body. This might be with a CT scan.
• Getting a sample of tissue for testing. A biopsy procedure often involves using a needle to take some of the suspicious tissue for testing. The tissue goes to a lab where tests can show if you have cancer and what type. Sometimes surgery is needed to get the tissue sample.

Myxofibrosarcoma can be hard to diagnose because it can look like other types of cancer and other conditions that aren't cancer. Careful imaging and lab tests can help your healthcare team make the correct diagnosis.

Treatment

Myxofibrosarcoma treatment often involves surgery to remove the cancer. Other treatments include radiation therapy and chemotherapy.

Myxofibrosarcoma can come back after surgery. This might be more likely if the cancer grows large or if lab tests show the cells are growing quickly. Your healthcare team may create a treatment plan with the goal of getting rid of all the cancer cells. To reach this goal, treatment might involve radiation therapy, chemotherapy or sometimes both treatments before or after surgery. These additional treatments may make it more likely that the cancer won't come back.

Which treatment is best for you will depend on your cancer, such as the size and location of the myxofibrosarcoma.

Surgery

The goal of surgery is to cut out as much of the cancer as possible. If all the myxofibrosarcoma is removed, surgery might be the only treatment needed.

Sometimes it's hard to get all the myxofibrosarcoma because this cancer tends to spread out as it grows. It also may grow close to important structures such as blood vessels and nerves that make surgery hard to perform. It can grow deep into the tissue. Sometimes surgeons can't see all the cancer to make sure it's removed.

In the past, surgeons often had to remove a limb to get rid of all the cancer. Today that's often not needed because of newer treatments. Sometimes radiation therapy and chemotherapy are used before surgery to shrink the cancer. This makes it easier to remove and might reduce the risk that the cancer will come back.

Radiation therapy

Radiation therapy uses powerful energy beams to kill cancer cells. The energy beams can come from X-rays, protons and other sources.

Radiation might be done before surgery to help shrink the myxofibrosarcoma. It also can be done after surgery to kill any cancer cells that might be left behind.

Chemotherapy

Chemotherapy treats cancer with strong medicines. It might help control a myxofibrosarcoma that's growing quickly. It might be an option if myxofibrosarcoma spreads to other parts of the body.

Clinical trials

Clinical trials are studies of new treatments. These studies provide a chance to try the latest treatments. The risk of side effects might not be known. Ask your healthcare team if you might be able to be in a clinical trial.

Preparing for an appointment

Make an appointment with a doctor or other healthcare professional if you have any symptoms that worry you. If your healthcare professional thinks that you might have myxofibrosarcoma, you may be referred to a specialist. Specialists who care for people with myxofibrosarcoma include:

• Cancer doctors, called medical oncologists.
• Surgeons who specialize in operating on people with cancer, such as orthopedic oncologists or surgical oncologists.
• Doctors who specialize in using radiation therapy to treat cancer, called radiation oncologists.

Appointments can be short and being prepared can help. Here's some information that may help you get ready.

What you can do

When you make the appointment, ask if there's anything you need to do in advance, such as fasting before having a specific test. Make a list of:

• Your symptoms, including any that seem unrelated to the reason for your appointment.
• Key personal information, including major stresses, recent life changes and family medical history.
• All medications, vitamins or other supplements you take, including the doses.
• Questions to ask your healthcare professional.

Take a family member or friend along, if possible, to help you remember the information you're given.

For myxofibrosarcoma, some basic questions to ask your healthcare professional include:

• Do I have cancer?
• Do I need to have the cancer removed?
• Do I need more tests?
• What are my treatment options?
• What are the potential risks for these treatment options?
• Do any of the treatments cure my cancer?
• Can I have a copy of my pathology report?
• How much time can I take to consider my treatment options?
• Are there brochures or other printed materials that I can take with me? What websites do you recommend?
• What would happen if I choose to not have treatment?

Don't hesitate to ask other questions.

What to expect from your doctor

Your healthcare professional may ask about your symptoms, such as:

• When did your symptoms begin?
• 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?