Thymoma - mediastinal

Alternative names
Mediastinal tumor; Lymphoma - mediastinal

Mediastinal tumors form in the cavity that separates the lungs. This cavity contains the heart, large blood vessels, trachea, thymus, and connective tissues.

Causes, incidence, and risk factors

The mediastinum is the part of the chest between the sternum and the spinal column. It contains the esophagus, trachea, heart, and other important structures. The mediastinum is divided into three sections:

  • The anterior (front)  
  • The middle  
  • The posterior (back)

Overall, mediastinal tumors are rare.

The most common location for tumors within the mediastinum varies according to the age of the patient. In children, tumors are more common in the posterior mediastinum. These often begin in the nerves and are often benign.

In contrast, most mediastinal tumors in adults occur in the anterior mediastinum and are usually malignant (cancerous) lymphomas or thymomas. These occur most commonly in people aged 30-50.


Almost half of mediastinal tumors cause no symptoms and are discovered on a chest x-ray performed for another reason. When present, symptoms are related to compression of local structures and may include:

  • Cough  
  • Shortness of breath  
  • Chest pain  
  • Fever  
  • Chills  
  • Night sweats  
  • Coughing up blood (hemoptysis)  
  • Hoarseness

Signs and tests

Mediastinal tumors are first suspected during history and physical examination which may reveal:

  • Fever  
  • Unintentional weight loss  
  • Lymphadenopathy (swollen or tender lymph nodes)  
  • Wheezing  
  • Stridor

Further diagnostic evaluation typically includes:

  • Chest x-ray  
  • CT scan of the chest  
  • MRI of the chest  
  • CT-guided needle biopsy  
  • Mediastinoscopy with biopsy


Treatment for mediastinal tumors varies based on the type of tumor.

  • For thymic cancers, surgery is the primary treatment of choice followed by radiation or chemotherapy, depending on the stage of the tumor and the success of the surgery.  
  • For lymphomas, chemotherapy followed by radiation is the treatment of choice.  
  • For neurogenic tumors of the posterior mediastinum, surgery is the treatment of choice.

Expectations (prognosis)
Prognosis varies based on the type of tumor. Different tumors have varying responses to chemotherapy and radiation.

Complications of mediastinal tumors include invasion of surrounding structures such as the heart, pericardium (the lining around the heart), and great vessels (the aorta and vena cava). Spinal cord compression is a complication seen in tumors of the posterior mediastinum. Radiation, surgery, and chemotherapy can all have serious complications.

Calling your health care provider
Call your health care provider if you notice symptoms of a mediastinal tumor.

Johns Hopkins patient information

Last revised: December 4, 2012
by Harutyun Medina, M.D.

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