by EBSCO Medical Review Board


A mediastinal mass is a growth in the center of the chest. It is in the space between the 2 lungs and the breastbone and spine. There are 7 major items in this area:

  • Heart
  • Aorta—major blood vessel
  • Esopahgus—tube that connects mouth and stomach
  • Thymus—part of the immune system
  • Trachea—windpipe
  • Lymph nodes
  • Nerves

The mass may grow in any of them.


There are several types of mediastinal masses. The cause will depend on what the mass is growing from. For example, masses in:

  • Area closer to the breastbone (anterior) may be caused by:
  • Lymphoma
  • Growth from the thymus (thymoma)
  • Germ cell tumor
  • Tumor that started in thyroid

Middle area may be caused by:

  • Cyst on windpipe or the heart
  • Lymphoma
  • Tumor from the esophagus, may or may not be cancer
  • Aneurysm—bulging wall—of the aorta

Area closer to the spine (posterior) may be caused by:

  • Neurogenic tumors on nerves
  • Cyst
  • Aneurysm—bulge in blood vessel wall

Risk Factors

These masses are more common in people who are 30 to 50 years of age. They can happen at any age.

People who have had family members with mediastinal cancer are also at higher risk.


Some people do not have symptoms. Those that do may have:

  • Cough with or without blood
  • Chest pain
  • Problem with breathing
  • Problem with swallowing
  • Voice changes, hoarseness
  • Unexplained weight loss
  • Fever, chills, and night sweats


You will be asked about your symptoms and past health. A physical exam will be done.

Your doctor might order:

  • Chest x-ray
  • CT scan of the chest
  • Biopsy—sample of tissue is taken from the area for study


Treatment will depend on the type and place of the tumor. Some may not need treatment but will be watched for changes. Masses that are causing problems may need to be treated with:

  • Surgery to remove tissue
  • Radiation or chemotherapy to shrink tissue


There are no known ways to prevent a mediastinal tumor.


American Cancer Society 

National Cancer Institute 


Canadian Cancer Society 

The College of Family Physicians Canada 


About mediastinal masses. Stanford Health Care website. Available at: Accessed January 15, 2019.

Carter BW, Marom EM, Detterbeck FC: Approaching the patient with an anterior mediastinal mass: a guide for clinicians. J Thorac Oncol. 2014 Sep;9 (9 Suppl 2)

Mediastinal masses. Merck Manual Professional Version website. Available at: Updated October 2017. Accessed January 15, 2019.

Mediastinal masses. Swedish Medical Center website. Available at: Accessed January 15, 2019.

Mediastinal tumors. Cedars-Sinai website. Available at: Accessed January 15, 2019.

What are mediastinal tumors? Northwestern Medicine website. Available at: Accessed January 15, 2019.

Revision Information

  • Reviewer: EBSCO Medical Review Board Mohei Abouzied, MD
  • Review Date: 06/2020
  • Update Date: 06/30/2020