The central portion of the chest cavity located behind the sternum (breast bone) and between the lungs and extending from the neck above to the diaphragm below is known as the mediastinum. The mediastinum contains the heart, thoracic aorta, trachea (airway), esophagus (swallowing passage), thymus gland, and lymph nodes. Mediastinal tumors, both benign and malignant (cancerous) are rare but do occur.
While mediastinal tumors occur more frequently in people between the ages of 30 and 50 years, they can develop at any age. Mediastinal tumors occurring in children are generally not cancerous and arise in the nerves. In adults, on the other hand, mediastinal tumors are often malignant.
Mediastinal tumors vary in location. In children they typically occur toward the back of the mediastinum, while in adults they generally occur in the front.
Malignant mediastinal tumors are most often one of 3 types:
- germ cell tumors (ovarian and testicular cancers)
- lymphoma (cancer of the lymph nodes/lymph cells)
- thymoma (arising in the thymus gland)
Causes of Mediastinal Tumors
While the causes of mediastinal tumors are as varied as the different types of these tumor, a past history of radiation therapy (for breast cancer or lymphoma) may precede the development of cancers within the mediastinum. The location and type of tumor help define the origin of these tumors.
Symptoms Mediastinal Tumors
Mediastinal tumors frequently cause no symptoms at all. When they do cause symptoms, these are usually due to pressure from the enlarging tumor. Symptoms may include chest pain, coughing, hoarseness, difficulty swallowing, shortness of breath, and/or unexpected weight loss.
Diagnosis of Mediastinal Tumors
The following are some of the most common tests used to diagnose mediastinal tumors:
- Chest X-rays, which depict the interior of the chest but do not show the mediastinum well since it is hidden behind the breast bone.
- Computed Tomography (CT scans), which produce a series of images of the inside of the body taken at different depths and angles to reveal a higher level of detail than provided by chest x-rays. To ensure that your blood vessels and organs show up clearly in these scans, dye may be swallowed or injected into a vein when the CT scan is being performed.
- Magnetic Resonance Imaging (MRI scan), in which a detailed image of your internal organs and tissues is created using magnetic field and radio waves.
Some blood tests may be useful in determining certain types of mediastinal tumors. Some mediastinal tumors require a tissue diagnosis using a needle biopsy, often under CT scan guidance, or mediastinoscopy and biopsy, in which a scope is inserted behind the breast bone and advanced into the mediastinum to the tumor. Diagnostic tests will depend on the type and location of the tumor.
Treatment of Mediastinal Tumors
The treatment options for mediastinal tumors are numerous and dictated by the specific type of tumor, its location within the mediastinum, and the symptoms it is causing. For example, germ cell tumors are usually treated with chemotherapy, as are lymphomas, with the possibility for radiation afterwards. Neurogenic tumors are usually treated surgically. Thymomas are generally removed using minimally invasive thoracic surgery, a sternotomy, or a thoracotomy.
The thoracic surgeon will discuss the diagnosis and treatment options with you and help you to determine the best course of action for your specific tumor.
Take the Next Step
Contact the Thoracic Cancer Clinic at the University of Michigan to assemble a team of specialists and construct a plan of action.