• Guidelines for treating this cancer have been developed by the Lung Tumour Group.
  
• For health professional information on treating this cancer, please see our Cancer Management Guidelines.
• The thymus is a small organ inside the chest, behind the breastbone. It sits just in front of and above the heart and may extend to the root of the neck.
• The thymus is large in infants. It grows until puberty and then gradually decreases in size during adulthood as it is replaced with fat.
• The thymus is divided into two lobes that are surrounded by a thin layer of tissue.
• The thymus is made up of two types of cells: epithelial cells and lymphocytes.
• Epithelial cells are the cells that line the thymus, and are the cells of origin for thymic-related cancers such as thymoma and thymic carcinoma.
• One of the thymus functions is to help control the immune system.
• The thymus is part of the lymphatic system. T Lymphocytes are a type of white blood cell that develop in the thymus, especially in early life. These cells help protect the body from infections and viruses. If lymphocytes become cancerous, they can develop into lymphoma.
• Thymus cancers have different names including thymomas, thymic carcinomas, thymic epithelial tumor or thymic carcinoid tumors.
• Thymus cancers are very rare and may be difficult to diagnose and treat.

What causes it and who gets it?

Listed below are some of the known risk factors for this cancer. Not all of the risk factors below may cause this cancer, but they may be contributing factors.

• The cause of thymus cancer is unknown.
• Patients are usually between 40 and 60 years of age.
• There is no evidence of gender related differences in this type of cancer.
  
• Thymus cancer and myasthenia gravis (a chronic disease that causes muscle weakness) are often associated.
• Statistics
  ^{[NOTE:  Available statistics do not have information about the inclusion of transgender and gender diverse participants. It is unknown how these statistics apply to transgender and gender diverse people.  Patients are advised to speak with their primary care provider or specialists about their individual considerations and recommendations]}
  
• BC
• Canada

Can I help to prevent it?

There is no known way to prevent thymus cancer.

Screening for this cancer

No effective screening program exists for this cancer yet.

Patients with myasthenia gravis are regularly checked for thymus cancer.

Signs and Symptoms

• There are often no symptoms of thymus cancer.
• If the growing tumour presses against other organs, the following chest symptoms may result:
• coughing
• shortness of breath
• difficulty breathing (dyspnea)
• difficulty swallowing (dysphagia)
• chest tightness or pain
• If the tumour presses on the vena cava (the great vessel that returns blood to the heart) the following symptoms might be noticed:
• swelling in the neck and face
• feeling light-headed
• headaches
• Advanced tumours may cause chest pain.
• This cancer is sometimes accompanied by immune disorders and low red blood cell counts.