Thymoma & Thymic Carcinoma

The thymus is a small organ located above the heart. It helps develop immune system cells known as lymphocytes. Thymoma and thymic carcinoma, two different types of thymus cancer, occur when a cell in the organ mutates and begins rapidly growing and dividing.

In addition to lymphocytes, the thymus is also made up of epithelial cells. These cells form the organ’s outer layer, known as the capsule. Thymoma and thymic carcinoma both start in the epithelial cells, though lymphocytes can be mixed in with the tumor.

Thymic cancer that is contained within the capsule is early-stage disease. If the cancer has broken out of the capsule, it is more advanced disease.

Only a few hundred cases of thymus cancer are diagnosed in the United States each year. Most patients are over 70 years old.

Types of thymus cancer

Doctors believe that all tumors that develop from thymic epithelial cells can metastasize, so they are all classified as cancer.

There are two main types of thymoma:

• Type A thymoma: This cancer has spindle-shaped epithelial cells that have turned cancerous. The tumor may or not include any lymphocytes. The prognosis for thymoma Type A patients is typically very good.
• Type B thymoma: There are several subtypes of Type B thymoma. Each can have its own appearance under a microscope. The prognosis for this disease varies depending on the subtype.

Thymic carcinoma develops from the same type of cells as thymoma, but the two are different diseases. Thymic carcinoma tends to behave more aggressively and is more likely to spread to other parts of the body than thymoma.

Thymoma and myasthenia gravis

Because the thymus is part of the immune system, thymoma can cause patients to develop autoimmune diseases. These cause the body’s immune system to attack healthy cells.

Myasthenia gravis (MG) is the most common autoimmune disease caused by thymoma. MG causes muscle weakness; shortness of breath; and a number of symptoms involving the face, head and neck. If a patient has MG caused by thymoma, curing the thymoma also can resolve the MG.

Symptoms

Thymus cancers often do not cause symptoms. When they do, symptoms include a persistent cough and a constant feeling of pressure in the chest. Learn more, including other possible diagnoses and information on screening, on the thymoma and thymic carcinoma symptoms page.

Diagnosis

Thymoma and thymic carcinoma are diagnosed by retrieving suspected cancer tissue and studying it under a microscope. Read more about how thymoma and thymic carcinoma are diagnosed.

Typical treatment options

Treatment for cancers of the thymus includes surgery, radiation therapy and chemotherapy. Clinical trials are also an option for many patients. Learn more about these treatments, including side effects and recovery times, on the thymoma and thymic carcinoma treatment page.

Risk factors

A risk factor is anything that increases the chance that a person will develop a particular disease. There are few known risk factors for thymoma and thymic carcinoma. The disease has not been linked to family history or specific behaviors.

The main risk factors for these cancers are:

• Age: Thymus cancer is rare in children and young adults. The disease becomes more common as people enter middle age, with the number of cases peaking among people in their 70s.
• Race: In the U.S., thymoma is most common among people with Asian/Pacific Islander heritage.

Are thymus cancers hereditary?

Most cases of thymoma and thymic carcinoma are not linked to any genetic condition that can be passed down from parent to child. There may be a genetic link in a small number of cases. Doctors are conducting research into possible connections.

Learn more about thymoma & thymic carcinoma:

• Thymoma & thymic carcinoma symptoms
• Thymoma & thymic carcinoma diagnosis
• Thymoma & thymic carcinoma stages
• Thymoma & thymic carcinoma treatment 

Why choose UT MD Anderson for your thymoma care?

Thymoma is a rare cancer and like all cancers, it can be serious. With just a few hundred cases diagnosed in the United States each year, it is important to find a team with experience treating this disease.

As a top-ranked cancer center, UT MD Anderson offers specialized treatments for thymoma patients. If you choose UT MD Anderson for your thymoma care, you will be treated by a multidisciplinary team of doctors and other care providers with special expertise in this disease. This team includes medical oncologists, surgeons, radiation oncologists and more. All are experts in their fields and the treatment of thymoma. They work together closely to customize the best treatment for you.

Groundbreaking research

UT MD Anderson's researchers are pioneering remarkable advances to give you the best chance for fighting thymoma. These include:

• Advanced surgical techniques that can improve outcomes while shortening hospital stays and recovery times.
• Targeted radiation therapy that focuses on cancer cells while minimizing damage to healthy nearby tissue.
• New cancer medicines, including immunotherapies that recruit the body’s own immune system in the fight against cancer and targeted therapies designed to slow or stop the disease’s growth.

Many clinical trials at UT MD Anderson are not available at other cancer centers. In fact, we offer clinical trials for various stages of thymoma, including treatments for thymoma in its early stages, thymoma that has spread to other parts of the body, and thymoma that has returned after earlier, successful treatment.

And, at UT MD Anderson you're surrounded by the strength of one of the nation's top-ranked cancer centers. We have all the support and wellness services needed to treat the whole person – not just the disease.