The mediastinum is the area that separates the lungs. It is surrounded by the breastbone in front and the spine in back, with the lungs on either side. It encompasses the heart, aorta, esophagus, thymus (a gland in the back of the neck) and trachea (windpipe). When tumors develop in this area, they are called mediastinal tumors.
Mediastinal tumors are rare but, due to their location, can be serious. As the tumors grow, they can cause pressure on the spinal cord, the lungs, the heart and heart lining and trachea.
The mediastinum is comprised of three sections: the anterior (front), middle and posterior (back). Different types of tumors tend to develop in each section of the mediastinum.
Anterior mediastinal tumors include:
- Germ cell tumors (neoplasms) - benign in about two-thirds of cases.
- Lymphoma including Hodgkin's and non -Hodgkin's disease.
- Thymoma and thymic cysts – cysts that develop in the thymus, a butterfly-shaped gland at the base of the neck.
- Thyroid mass mediastinal – a benign growth such as a goiter. These masses may develop into cancer.
Middle mediastinal tumors include:
- Bronchogenic cysts - a disease in the respiratory system.
- Lymphadenopathy mediastinal - disease in the lymph nodes.
- Pericardial cysts which include growths that start in the lining of the heart.
- Tracheal tumors.
Posterior mediastinal tumors include:
- Lymphadenopathy mediastinal - disease of the lymph nodes.
- Neurogenic neoplasm mediastinal tumors - cells that grow outside of the normal cell area and are not part of the surrounding tissue.
- Extramedullary hematopoiesis - a rare mass formed from bone marrow.
- Neuroenteric cyst mediastinal - sacs with pus that develop outside of the normal tissue.
In almost half of the new cases of mediastinal tumors, there are no symptoms. The tumors go undiagnosed until the need for a chest X-ray. Depending on the size and location of the tumor, symptoms may develop due to pressure on the spinal cord, heart or heart lining (pericardium) and may include:
- Coughing with or without blood, shortness of breath and hoarseness.
- Night sweats, chills or fever.
- Wheezing or a high-pitched breathing noise.
- Unexplained weight loss and anemia.
- Swollen or tender lymph nodes.
Causes and Risk Factors
Mediastinal tumors are rare. Where tumors will develop often depends on the age of the patient. Tumors presenting in the anterior (front) part of the mediastinum tend to occur in people ages 30 to 50 years of age. Mediastinal tumors in children are more often benign.
To confirm the diagnosis of a mediastinal tumor, your doctor may order tests for you, such as a:
- Chest x-ray
- Computed tomography (CT) scan or a CT-guided biopsy of the chest.
- Magnetic resonance imaging (MRI) of the chest.
- Mediastinoscopy, a surgical procedure, with a biopsy of the tissue. A mediastinalscope is inserted into the mediastinum through a small incision in the chest. The scope has a camera on the end to give your doctor a clear view of the area. Tissue may be removed to perform a biopsy to test the cells for signs of cancer.
Mediastinal tumors may be treated with surgery, chemotherapy and radiation or a combination of these options. The treatment will depend on the type of tumor, location and the overall health of the patient. For example, thymic cancers always require surgery, followed by chemotherapy and radiation but lymphomas usually require chemotherapy, followed by radiation.
Though there are risks associated with any procedure, the doctors at Cedars-Sinai's Women's Guild Lung Institute have expertise in video-assisted thorascopy (VATS) mediastinoscopy, a minimally invasive approach to surgically removing tumors. Minimally invasive surgeries typically result in less postoperative pain, reduced risk of infection, less bleeding and a quicker return to your normal activities.
With input from the multidisciplinary team at Cedars-Sinai, you and your doctor will discuss which treatment plan works best for you.