Mediastinal tumors develop in the mediastinum. The mediastinum is the area in the middle of the chest that lies between the sternum (breastbone) and spinal column. The area contains vital organs including the heart, esophagus, and trachea.Mediastinal tumors develop in one of three areas of the mediastinum: the anterior (front), the middle, or the posterior (back). The position of the tumor in the mediastinum typically depends on patient’s age.Children are more likely to develop them in the back of the mediastinum. These are often benign, or noncancerous. Adults are more likely to develop them in the front of the mediastinum. These tumors are typically malignant, or cancerous. Affected adults are usually between the ages of 30 and 50. As a whole, mediastinal tumors are very rare.
There are a number of different types of mediastinal tumors. What causes these tumors depends on where they form in the mediastinum.
In the front of the mediastinum, tumors can be caused by:
- lymphoma, including Hodgkin and non-Hodgkin’s lymphoma
- thymoma and thymic cyst (a tumor of the thymus)
- thyroid mass mediastinal (generally a benign growth, but it can sometimes be cancerous)
In the middle of the mediastinum, tumors can be caused by:
- bronchogenic cyst (a benign growth that starts in the respiratory system)
- lymphadenopathy mediastinal, or enlargement of the lymph nodes
- pericardial cyst (a benign growth on the heart lining)
- thyroid mass mediastinal
- tracheal tumors (usually benign growths)
- vascular complications, such as swelling of the aorta
In the back of the mediastinum, tumors can be caused by:
- extramedullary haematopoiesis (rare growths that start in the bone marrow and are related to severe anemia)
- lymphadenopathy mediastinal (enlarged lymph nodes)
- neuroenteric cyst mediastinal (a rare growth involving both the nerves and the gastrointestinal system)
- neurogenic neoplasm mediastinal (cancerous cells of the nerves)
Neurogenic neoplasm mediastinal is the most common cause of posterior mediastinal tumor and about 70 percent of these are benign.
Tumors that form in the mediastinum are also known as primary tumors. Sometimes mediastinal tumors will develop because cancer from another part of the body has spread. The spread of cancer from one area of the body to another is known as metastasis. Mediastinal tumors that develop because of metastasis are known as a secondary tumor.
Symptoms of a Mediastinal Tumor
If you have a mediastinal tumor, you may not have any symptoms. Tumors are typically found during a chest X-ray that was ordered to diagnose another health condition.
If symptoms develop, it’s often because the tumor is pushing on surrounding organs. Symptoms can include:
- shortness of breath
- chest pain
- night sweats
- coughing up blood
- unexplained weight loss
- swollen lymph nodes
- respiratory blockage
How Are Mediastinal Tumors Diagnosed?
If you have symptoms of a mediastinal tumor, your doctor will order additional tests to confirm your diagnosis. These tests may include:
- a chest X-ray
- a CT scan of the chest
- an MRI of the chest
- a mediastinoscopy with biopsy
- PET scan may be necessary in some patients.
Mediastinoscopy with biopsy is used to collect cells from the mediastinum. During this test, you’ll receive anesthesia. Then, your doctor will make a small incision under the breastbone. They’ll remove a sample of tissue and have it analyzed to see if cancer is present. This procedure will help your doctor accurately diagnose the type of tumor you have.
How Are Mediastinal Tumors Treated?
The treatment may involve surgery, chemotherapy and or radiotherapy. Various combinations and sequences can be used depending upon the type and location of tumour.
Surgery is often used first to remove the tumor. Once the tumor is removed, your doctor may use chemotherapy and/or radiation therapy to destroy remaining cancer cells.In case the surgeon feels that it is too big to be removed, the treating team may decide for chemotherapy first to reduce the size and then go for the surgery.
Chemotherapy regime would depend upon the type of tumour. Radiotherapy can be used in certain types and locations.