Skip to main content

ACS & ASCO are Stronger Together: Cancer.Net content is now available on


If You Have Thymus Cancer

What is thymus cancer?

Cancer can start any place in the body. Cancer that starts in the thymus gland is called thymus cancer. It starts when cells in the thymus gland grow out of control and crowd out normal cells. This makes it hard for the body to work the way it should.

Cancer cells can spread to other parts of the body. Cancer cells in the thymus can sometimes travel to lungs or the bone and grow there. When cancer cells do this, it’s called metastasis (pronounced meh-TAS-tuh-sis).

Cancer is always named for the place where it starts, because when the cancer cells grow in a new place, they still look the same as the cells where the cancer started. So when thymus cancer spreads to the lung (or any other place), it’s still called thymus cancer. It’s not called lung cancer unless it starts from cells in the lung.

illustration showing the thymus gland in relation to the trachea, superior vena cava, right and left lungs and aorta

The thymus

Ask your doctor to use this picture to show you where your cancer is.

What is the thymus?

The thymus gland is just behind your breast bone in the front of your chest. It's part of your immune system. 

Different kinds of thymus cancer

There are 2 main types of thymus tumors. Your doctor can tell you more about the kind you have. 

  • Thymomas tend to grow slowly and rarely spread to other parts of the body.
  • Thymic carcinomas tend to grow faster and are more likely to spread to other parts of the body. (Carcinoma is another name for cancer. It’s pronounced CAR-sin-O-muh.)

Most people with thymus cancer don't have any symptoms. The tumor is often found when patients get an X-ray or scan because of some other health problem. If the tumor gets big enough to press on blood vessels and/or the windpipe, you may have trouble breathing, cough, or chest pain. The doctor will ask you questions about your health and do a physical and exam.

Questions to ask the doctor

  • Why do you think I have a thymus tumor?
  • Is there a chance I don’t have a thymus tumor?
  • How do you know I have thymus cancer?
  • Would you please write down the kind of tumor you think I have?
  • What will happen next?

If signs are pointing to a thymus tumor, more tests will be done. Here are some of the tests you may need:

    How does my doctor know I have thymus cancer?

    Tests that may be done

    Blood tests: Blood tests alone can’t tell if a thymus tumor is cancer. But they can help find out more about your overall health.

    Chest x-ray: This is often the first test done. It can show thymus tumors.

    CT scan: This is also called a “CAT scan.” It’s a special kind of x-ray that takes detailed pictures of the thymus and can show if the cancer has spread.

    MRI scan: This test uses radio waves and strong magnets instead of x-rays to take pictures. MRI scans can be used to look for thymus cancer that has spread.

    PET scan: In this test, you are given a special type of sugar that can be seen inside your body with a camera. If there is cancer, this sugar shows up as “hot spots” where the cancer is found. This test is often done at the same time as a CT scan.

    Biopsy (BY-op-see): in most cases, a biopsy is the only way to tell for sure if you have cancer. The doctor takes out a small piece of tissue and it's checked for cancer cells. In thymus cancer, imaging tests are often all that's needed to know there's a thymus tumor. The tumor is taken out and then it's tested to see if there are cancer cells in it.

    Questions to ask the doctor

    • What tests do I need to have?
    • Where will they be done?
    • Who will do these tests?
    • Who can explain them to me?
    • How and when will I get the results?
    • Who will explain the results to me?
    • What do I need to do next?

    How serious is my cancer?

    If you have thymus cancer, the doctor will want to find out how far it has spread. This is called staging. You may have heard other people say that their cancer was “stage 1” or “stage 2.” Your doctor will want to find out the stage of your cancer to help decide what type of treatment is best for you.

    The stage describes the growth or spread of the cancer through the thymus gland. It also tells if the cancer has spread to other organs of your body that are close by or far away.

    Your cancer can be stage 1, 2, 3, or 4. The lower the number, the less the cancer has spread. A higher number, like stage 4, means a more serious cancer that has spread beyond the thymus. Be sure to ask the doctor about the cancer stage and what it means for you.

    Questions to ask the doctor

    • Do you know the stage of the cancer?
    • If not, how and when will you find out the stage of the cancer?
    • Would you explain to me what the stage means in my case?
    • Based on the stage of the cancer, how long do you think I’ll live?
    • What will happen next?

    What kind of treatment will I need?

    There are many ways to treat thymus cancer but surgery is the main treatment. The treatment plan that’s best for you will depend on:

    • The stage of the cancer
    • The chance all of the cancer can be taken out with surgery
    • Your age
    • Other health problems you have
    • Your feelings about the treatment and the side effects that come with it

    Depending on the type and stage of your thymus cancer, you may need more than 1 type of treatment.

    Surgery for thymus cancer

    Most patients with thymus cancer have some type of surgery . Surgery is done to take out the tumor and all of the thymus gland. Sometimes lymph nodes are taken out, too.

    Side effects of surgery

    Any type of surgery can have risks and side effects. Be sure to ask the doctor what you can expect. If you have problems, let your doctors know.

    Radiation treatments

    Radiation uses high-energy rays (like x-rays) to kill cancer cells. This treatment may be used to: 

    • Kill any cancer cells that may be left after surgery
    • Help shrink a tumor before surgery, so it's easier to take out
    • Ease problems the tumor causes, like pressing on nerves or blood vessels

    Side effects of radiation treatments

    If your doctor suggests radiation treatment, talk about what side effects might happen. Side effects depend on the type of radiation that’s used. The most common side effects of radiation are:

    • Skin changes where the radiation is given
    • Throat sores
    • Trouble swallowing and eating
    • Sick stomach and throwing up
    • Feeling very tired (fatigue)
    • Lung damage

    Most side effects get better after treatment ends. Some might last longer. Talk to your cancer care team about what you can expect.


    Chemo is the short word for chemotherapy – the use of drugs to fight cancer. These drugs go into the blood and spread through the body. Chemo is given in cycles or rounds. Each round of treatment is followed by a break. Most of the time, 2 or more chemo drugs are given. Treatment often lasts for many months.

    Chemo may be given to:

    • Kill any cancer cells that may be left after surgery
    • Help shrink a tumor that can't be taken out with surgery
    • Along with radiation to help it work better

    Side effects of chemo

    Chemo can make you feel very tired, sick to your stomach, and cause your hair to fall out. But these problems go away after treatment ends.

    There are ways to treat most chemo side effects. If you have side effects, be sure to talk to your cancer care team so they can help.

    Clinical trials

    Clinical trials are research studies that test new drugs or other treatments in people. They compare standard treatments with others that may be better.

    If you would like to be in a clinical trial, start by asking your doctor if your clinic or hospital conducts clinical trials. See Clinical Trials to learn more. Clinical trials are one way to get the newest cancer treatment. They are the best way for doctors to find better ways to treat cancer. If your doctor can find one that’s studying the kind of cancer you have, it’s up to you whether to take part. And if you do sign up for a clinical trial, you can always stop at any time.

    What about other treatments I hear about?

    When you have cancer you might hear about other ways to treat the cancer or treat your symptoms. These may not always be standard medical treatments. These treatments may be vitamins, herbs, special diets, and other things. You may wonder about these treatments.

    Some of these are known to help, but many have not been tested. Some have been shown not to help. A few have even been found to be harmful. Talk to your doctor about anything you’re thinking about using, whether it’s a vitamin, a diet, or anything else.

    Questions to ask the doctor

    • What treatment do you think is best for me?
    • What’s the goal of this treatment? Do you think it could cure the cancer?
    • Will treatment include surgery? If so, who will do the surgery?
    • What will the surgery be like?
    • Will I need other types of treatment, too?
    • What’s the goal of these treatments?
    • What side effects could I have from these treatments?
    • What can I do about side effects that I might have?
    • Is there a clinical trial that might be right for me?
    • What about special vitamins or diets that friends tell me about? How will I know if they are safe?
    • How soon do I need to start treatment?
    • What should I do to be ready for treatment?
    • Will my insurance cover treatment?
    • How much will I have to pay?
    • Is there anything I can do to help the treatment work better?
    • What’s the next step?

    What will happen after treatment?

    Most people do very well after treatment, but you may need follow-up care for the rest of your life.  Your cancer care team will tell you what tests you need and how often they should be done.

    Having cancer and dealing with treatment can be hard, but it can also be a time to look at your life in new ways. You might be thinking about how to improve your health. Call us at 1-800-227-2345 or talk to your cancer care team to find out what you can do to feel better.

    You can’t change the fact that you have cancer. What you can change is how you live the rest of your life – making healthy choices and feeling as good as you can.

    For connecting and sharing during a cancer journey

    Anyone with cancer, their caregivers, families, and friends, can benefit from help and support. The American Cancer Society offers the Cancer Survivors Network (CSN), a safe place to connect with others who share similar interests and experiences. We also partner with CaringBridge, a free online tool that helps people dealing with illnesses like cancer stay in touch with their friends, family members, and support network by creating their own personal page where they share their journey and health updates.   

    The American Cancer Society medical and editorial content team

    Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as editors and translators with extensive experience in medical writing.

    Biopsy (BY-op-see): Taking out a small piece of tissue to see if there are cancer cells in it.

    Immune system: the complex system by which the body resists infection by germs and rejects transplanted tissues or organs. The immune system may also help the body fight some cancers.

    Lymph (limf) nodes: small, bean-shaped collections of immune system tissue found all over the body and connected by lymph vessels; also called lymph glands.

    Metastasis (meh-TAS-tuh-sis): cancer cells that have spread from where they started to other places in the body.

    We have a lot more information for you. You can find it online at Or, you can call our toll-free number at 1-800-227-2345 to talk to one of our cancer information specialists.

    Last Revised: October 6, 2017

    American Cancer Society Emails

    Sign up to stay up-to-date with news, valuable information, and ways to get involved with the American Cancer Society.