Mediastinal Tumor

A group of tumors that include thymomas, lymphomas, germ cell tumors, and cysts is called mediastinal tumors. These abnormal cells often appear in the space between the lungs (the mediastinum). While some of these tumors are benign (noncancerous), some people may develop malignant (cancerous) tumors. The primary treatment for people who develop mediastinal tumors is surgery.

Moreover, the mediastinum is surrounded by the breastbone in front and the spine in back. The lungs are located on each side of the mediastinum. This space in the chest also contains other organs and tissues, including the heart, esophagus, thymus, thyroid, trachea, aorta, lymph nodes, and nerves. The thymus and lymph nodes are parts of the immune system that help the body fight against bacteria, viruses, and other germs that can make you ill.

In general, these tumors rarely affect people, and it accounts for less than 1% of people worldwide. The most common types of mediastinal tumors negatively affect the anterior part of the mediastinum. These include thymomas, benign mediastinal cysts, and lymphomas.

Types of Mediastinal Tumors

Healthcare professionals have divided these tumors into several categories based on where they are developing. For example, the anterior (front), middle, or posterior (back). Check some examples below:

Anterior Mediastinal Tumors

Thymoma and thymic carcinoma – The most common mediastinal tumors are thymomas. These are malignant tumors that develop in the thymus gland cells. Most of the time, these tumors grow slowly, but there is a type of cancer that is aggressive and easily spreads to surrounding tissues. It is called thymic carcinoma, and it also affects the thymus gland.
Thymic cysts – These growths are benign (noncancerous) and often require treatment if they put pressure on nearby tissues and cause symptoms.
Lymphoma – These include both Hodgkin lymphoma and non-Hodgkin lymphoma.
Germ cell tumor – This type of anterior mediastinal tumor commonly develops in the gonads (ovaries and testicles). In most cases, germ cell tumors are noncancerous.
Thyroid mass – Usually, this is a benign tumor similar to a goiter.

Middle Mediastinal Tumors

Bronchogenic cyst – This is a small and noncancerous cyst that is often filled with fluid or mucus.
Mediastinal lymphadenopathy – This is a condition that causes enlarged or swollen lymph nodes.
Pericardial cyst – This growth often appears in the fluid-filled sac that surrounds the heart (the pericardium).
Tracheal tumors – The tumors that develop in the trachea (windpipe) can be benign or malignant.
Esophageal tumors – Sometimes, people may develop tumors in the esophagus (food pipe) that can also be noncancerous or cancerous.
Esophageal diseases – In some cases, people may develop benign tumors that put pressure on the esophagus, causing some conditions. For example, diverticulum, achalasia, hiatal hernia, and others.
Blood vessel conditions – For example, aortic aneurysm, aortic dissection, and others.

Posterior Mediastinal Tumors

Neurogenic tumors – These tumors often develop in nerve tissue, and they are the most common type of posterior mediastinal tumors. Examples include nerve sheath tumors, ganglion cell tumors, and paragangliomas. In most cases, neurogenic tumors are noncancerous.
Mediastinal lymphadenopathy – This is a condition that causes lymph nodes to become enlarged in the back part of the mediastinum.
Extramedullary hematopoiesis (EMH) – This type of mediastinal tumor occurs rarely, and they affect the bone marrow.
Neuroenteric cyst – This is a rare growth that contains multiple tissue types.
Paravertebral diseases (health conditions that negatively affect the mid-spine) – For example, infectious, malignant, and traumatic abnormalities that develop in the middle of the spine (also called the thoracic spine).

Symptoms

About 40% to 50% of people who develop mediastinal tumors do not have any symptoms. However, doctors identify these tumors during a chest X-ray done for other reasons. The symptoms often appear when the tumor grows large enough and puts pressure on nearby tissues and organs. Generally, children experience symptoms more frequently than adults do. Check some general symptoms of mediastinal tumors below:

Chest pain (rarely)
Hoarseness
Hemoptysis (coughing up blood)
Swallowing problems (also known as dysphagia)
Fever, chills, or night sweats
Unexplained weight loss
Eye problems (including drooping eyelids and small pupils)
Swollen lymph nodes
Stridor (high-pitched and noisy breathing)

If you experience any of the previous symptoms, immediately contact your healthcare professional. Remember, early diagnosis and proper treatment often help prevent serious complications.

Causes and Risk Factors

In general, there are several reasons that contribute to mediastinal tumors. These include:

Uncontrolled cell growth – All tumors begin to develop when specific cells begin to multiply and grow abnormally. Nowadays, experts do not fully understand what exactly causes mediastinal tumors.
Response to an underlying condition – Some people may develop mediastinal tumors in response to inflammation or an underlying infection. For example, mediastinal tumors may develop in people with lymphadenopathy.
Atypical tissue development before birth – These tumors can be congenital (present at birth). For example, pericardial cysts, bronchogenic cysts, and germ cell tumors.

Moreover, doctors have identified some factors that could increase your risk of mediastinal tumors. Check some examples below:

Age – While anyone can develop mediastinal tumors, they mostly affect people between the ages of 30 and 50. In addition, adults usually develop anterior mediastinum tumors that are cancerous (such as lymphomas or thymomas), but children mostly develop posterior mediastinal tumors that are noncancerous.
Autoimmune disorders – The risk of developing mediastinal tumors increases even more if you already have an autoimmune disorder. For example, rheumatoid arthritis, myasthenia gravis, lupus, thyroiditis, Sjogren’s syndrome, and others.
Weakened immune system – If you are taking immunosuppressants or have the following health conditions, your immune system can weaken, making you more prone to mediastinal tumors. For example, HIV infection, cancer, and others.
Inherited genetic syndromes – There are some genetic conditions that may increase your risk of neurogenic tumors.

What Happens if Mediastinal Tumors are Left Untreated?

While some people with these tumors do not have symptoms, others may experience severe complications, especially if they leave it untreated. Check some of them below:

Respiratory compromise – For example, dyspnea (shortness of breath), stridor, severe cough, and other symptoms.
Vascular compression – Sometimes, the tumor puts pressure on the vena cava, which can cause SVC syndrome. This condition often causes facial, neck, and upper body swelling.
Neurological problems (such as Horner’s syndrome)
Cardiac and pulmonary problems
Metastasis – In such cases, the tumor breaks and spreads to other parts of the body.
Paraneoplastic syndromes
Treatment complications – These include nerve injury, bleeding, infections, and others.

The previous list does not contain all possible mediastinal tumor complications. Moreover, there is no way to prevent these tumors.

Diagnosis

Most of the time, mediastinal tumors are found accidentally during imaging tests done for other reasons. However, to confirm or rule out a mediastinal tumor, doctors often perform the following tests. For example:

Chest X-ray – This test is used to reveal tumors in the mediastinum.
CT (computerized tomography) scan – This is another imaging test used to get cross-sectional images of different structures in the body. In such cases, it is used to show the tumors in detail.
MRI (magnetic resonance imaging) scan – This test is used to determine the exact location and size of the tumor. It may also show whether the cancer has spread.
PET (positron emission tomography) scan – Doctors use this imaging test to diagnose lymphomas.
Blood tests – These tests are used to check for proteins or enzymes that are often associated with mediastinal tumors (also called tumor markers).
Biopsy – During this test, doctors will take a sample of the tumor for testing. They often check for cancerous cells.

Once you are diagnosed with a mediastinal tumor, physicians will perform additional imaging tests to determine the extent (stage) of the cancer. Usually, it helps doctors make the best treatment plan for you.

Treatment

While the primary treatment for people with mediastinal tumors is surgery, they may also recommend other treatment options. Check some examples below:

Surgery – Most of the time, people with thymomas, thymic carcinoma, neurogenic tumors, and other tumors need surgery to remove them. The most common surgery used is a sternotomy. During this procedure, surgeons will make a cut through the breastbone to remove the tumor. Sometimes, they may use a minimally invasive procedure to remove the tumor. It is called VATS (video-assisted thoracoscopic surgery).
Radiation therapy – This is a cancer treatment that uses powerful energy beams to destroy cancerous cells. The energy used in this therapy often comes from X-rays or protons, but it may also come from other sources. Doctors may also recommend radiation therapy along with chemotherapy when surgery is not an option.
Chemotherapy – This is another cancer treatment that involves strong medicines to destroy cancer cells. Your doctor may prescribe chemotherapy before surgery to shrink a large tumor or after surgery to destroy cancerous cells that may remain even after a successful surgery.
Antibiotics – Sometimes, people need antibiotics to treat an infection caused by mediastinal tumors.

Frequently Asked Questions

Is a mediastinal tumor serious?

Usually, these tumors can cause serious health problems without treatment, even if they are noncancerous. For example, the spreading of the tumor to the heart, major blood vessels (including aorta and vena cava), bone marrow, spinal cord, and other parts of the body.

What is the survival rate for mediastinal tumors?

In general, the survival rate is different among people with mediastinal tumors because it depends on several factors. These include the type and severity of the condition, existing health problems, gender, and age. However, the 5-year survival rate for thymomas is about 70%.

How do you treat a mediastinal mass?

The most common treatment for people with mediastinal tumors is surgery. However, if you develop a cancerous tumor, doctors may recommend additional treatment to destroy the cancer (including radiation therapy and chemotherapy). Ask your healthcare provider if you have any other questions.