Thymoma and thymic carcinoma are diseases in which malignant (cancer) cells form on the outside surface of the thymus.
The thymus, a small organ that lies in the upper chest under the breastbone, is part of the lymph system. It makes white blood cells, called lymphocytes, that protect the body against infections.
There are different types of tumors of the thymus. Thymomas and thymic carcinomas are rare tumors of the cells that are on the outside surface of the thymus. The tumor cells in a thymoma look similar to the normal cells of the thymus, grow slowly, and rarely spread beyond the thymus. On the other hand, the tumor cells in a thymic carcinoma look very different from the normal cells of the thymus, grow more quickly, and have usually spread to other parts of the body when the cancer is found. Thymic carcinoma is more difficult to treat than thymoma.
Having a disease called myasthenia gravis can affect the risk of developing thymoma.
People with thymoma often have other diseases as well. These diseases may include myasthenia gravis, polymyositis, lupus erythematosus, rheumatoid arthritis, thyroiditis, Sjogren syndrome, and hypogammaglobulinemia.
Possible signs of thymoma and thymic carcinoma include a cough and chest pain.
Sometimes thymoma and thymic carcinoma do not cause symptoms. The cancer may be found during a routine chest x-ray. The following symptoms may be caused by thymoma, thymic carcinoma, or other conditions. A doctor should be consulted if any of the following problems occur:
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A cough that doesn't go away.
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Chest pain.
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Trouble breathing.
Tests that examine the thymus are used to detect (find) thymoma or thymic carcinoma.
The following tests and procedures may be used:
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Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken.
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Chest x-ray: An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
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CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, such as the chest, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.
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MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body, such as the chest. This procedure is also called nuclear magnetic resonance imaging (NMRI).
Thymoma and thymic carcinoma are usually diagnosed, staged, and treated during surgery.
A biopsy of the tumor is done to diagnose the disease. The biopsy may be taken before or during surgery, using a thin needle to obtain the sample of cells (needle biopsy or fine-needle aspiration biopsy). A pathologist will view the sample under a microscope to check for cancer. If thymoma or thymic carcinoma is diagnosed, the pathologist will determine the type of cancer cell in the tumor. There may be more than one type of cancer cell in a thymoma. The surgeon will decide if all or part of the tumor can be removed by surgery. In some cases, lymph nodes and other tissues may be removed as well.
Certain factors affect prognosis (chance of recovery) and treatment options.
The prognosis (chance of recovery) and treatment options depend on the following:
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The stage of the cancer.
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The type of cancer cell.
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Whether the tumor can be removed completely by surgery.
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The patient's general health.
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Whether the cancer has just been diagnosed or has recurred (come back).
Stages of Thymoma and Thymic Carcinoma
Tests done to detect thymoma or thymic carcinoma are also used to stage the disease.
Staging is the process used to find out if cancer has spread from the thymus to other parts of the body. The findings made during surgery and the results of tests and procedures are used to determine the stage of the disease. It is important to know the stage in order to plan treatment.
The following stages are used for thymoma:
Noninvasive thymoma (stage I)
In stage I, cancer is found only within the thymus. All cancer cells are inside the capsule (sac) that surrounds the thymus.
Invasive thymoma (stage II, stage III, and stage IV)
Invasive thymoma includes stage II, stage III, and stage IV.
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In stage II, cancer has spread through the capsule and into the fat around the thymus or into the lining of the chest cavity.
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In stage III, cancer has spread to nearby organs in the chest, including the lung, the sac around the heart, or large blood vessels that carry blood to the heart.
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Stage IV is divided into stage IVA and stage IVB, depending on where the cancer has spread.
--In stage IVA, cancer has spread widely around the lungs and heart.
--In stage IVB, cancer has spread to the blood or lymph system
Thymic carcinomas have usually spread to other parts of the body when diagnosed.
The staging system used for thymomas is sometimes used for thymic carcinomas.
Recurrent Thymoma and Thymic Carcinoma
Recurrent thymoma and thymic carcinoma is cancer that has recurred (come back) after it has been treated. The cancer may come back in the thymus or in other parts of the body. Thymic carcinomas commonly recur. Thymomas may recur after a long time. There is also an increased risk of having another type of cancer after having a thymoma. For these reasons, lifelong follow-up is needed.
Treatment option overview
There are different types of treatment for patients with thymoma and thymic carcinoma.
Different types of treatments are available for patients with thymoma and thymic carcinoma. Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. Before starting treatment, patients may want to think about taking part in a clinical trial. A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment.
Clinical trials are taking place in many parts of the country. Information about ongoing clinical trials is available from the NCI Web site. Choosing the most appropriate cancer treatment is a decision that ideally involves the patient, family, and health care team.
Three types of standard treatment are used:
Surgery
Surgery to remove the tumor is the most common treatment of thymoma.
Even if the doctor removes all the cancer that can be seen at the time of the surgery, some patients may be given radiation therapy after surgery to kill any cancer cells that are left. Treatment given after the surgery, to increase the chances of a cure, is called adjuvant therapy.
Radiation therapy
Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.
Hormone therapy
Hormone therapy is a cancer treatment that removes hormones or blocks their action and stops cancer cells from growing. Hormones are substances produced by glands in the body and circulated in the bloodstream. Some hormones can cause certain cancers to grow. If tests show that the cancer cells have places where hormones can attach (receptors), drugs, surgery, or radiation therapy is used to reduce the production of hormones or block them from working.
Hormone therapy with drugs called corticosteroids may be used to treat thymoma or thymic carcinoma.
New types of treatment are being tested in clinical trials.
Chemotherapy
Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping the cells from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the spinal column, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). The way the chemotherapy is given depends on the type and stage of the cancer being treated.
This summary section refers to specific treatments under study in clinical trials, but it may not mention every new treatment being studied. Information about ongoing clinical trials is available from the NCI Web site.
Treatment options for Thymoma and Thymic Carcinoma
Noninvasive Thymoma and Thymic Carcinoma
Treatment of noninvasive thymoma and thymic carcinoma may include the following:
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Surgery to remove the tumor.
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Radiation therapy.
Invasive Thymoma and Thymic Carcinoma
Treatment of invasive thymoma and thymic carcinoma that may be completely removed by surgery includes the following:
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Surgery followed by radiation therapy.
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A clinical trial of other new treatments.
Treatment of invasive thymoma and thymic carcinoma that cannot be removed completely by surgery includes the following:
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Surgery to remove part of the tumor, followed by radiation therapy with or without chemotherapy.
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A clinical trial of chemotherapy using one or more anticancer drugs.
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A clinical trial of chemotherapy before surgery, with or without radiation therapy.
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A clinical trial of combination chemotherapy followed by radiation therapy.
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A clinical trial of other new treatments.
Recurrent Thymoma and Thymic Carcinoma
Treatment of recurrent thymoma and thymic carcinoma may include the following:
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Surgery with or without radiation therapy.
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Radiation therapy.
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Hormone therapy.
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A clinical trial of chemotherapy using one or more anticancer drugs.
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A clinical trial of other new treatments.
For more information from the NCI, please write to this address:
NCI Public Inquiries Office
Suite 3036A
6116 Executive Boulevard, MSC8322
Bethesda, MD 20892-8322
U.S. residents may call the National Cancer Institute's (NCI's) Cancer Information Service toll-free at 1-800-4-CANCER (1-800-422-6237) Monday through Friday from 9:00 a.m. to 4:30 p.m. Deaf and hard-of-hearing callers with TTY equipment may call 1-800-332-8615. Information about ongoing clinical trials is available from the NCI Web site www.cancer.gov/clinicaltrials.
Source: National Institutes of Health; National Cancer Institute
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 7/12/2007...#6196
