Patient Information:

Mediastinal Tumours –

Diagnosis and Management
 

This information sheet is designed to help you understand more about tumours that can occur in the mediastinum, how they are diagnosed, and the different ways they can be treated.
 

What is the Mediastinum?
 

The mediastinum is the space in the middle of your chest, located between your lungs. It contains many important organs and structures, including:

• The heart and major blood vessels (like the aorta, vena cava).

• The trachea (windpipe) and main bronchi (airways leading to the lungs).

• The esophagus (food pipe).

• Lymph nodes (small glands that are part of the immune system).

• The thymus gland (an organ involved in immune system development).

• Nerves (e.g., phrenic nerve, vagus nerve, sympathetic chain).

The mediastinum is often divided into three or four compartments for descriptive purposes:

• Anterior (front) mediastinum: Contains the thymus gland, lymph nodes, and fatty tissue.

• Middle mediastinum: Contains the heart, pericardium (sac around the heart), trachea, main bronchi, and lymph nodes.

• Posterior (back) mediastinum: Contains the esophagus, descending aorta, thoracic duct (a major lymphatic vessel), nerves, and lymph nodes.

  (Some classifications also include a superior mediastinum).

What are Mediastinal Tumours?
 

A mediastinal tumour is an abnormal growth of cells that develops in any of the tissues or organs located within the mediastinum. These tumours can be:

• Benign (Non-cancerous): These tumours do not spread to other parts of the body and are usually not life-threatening. However, they can grow and cause symptoms by pressing on nearby organs.

• Malignant (Cancerous): These tumours can invade nearby tissues and organs, and can spread (metastasize) to other parts of the body.
   

Mediastinal tumours can arise from any structure within the mediastinum. They are relatively uncommon.
 

Types of Mediastinal Tumours
 

The types of tumours found in the mediastinum vary depending on the compartment and the age of the patient.
 

Common Tumours by Compartment:
 

• Anterior Mediastinum:

  • Thymoma and Thymic Carcinoma: Tumours of the thymus gland (most common primary tumours in adults). Thymomas can be benign or malignant; thymic carcinomas are always malignant. Some thymomas are associated with autoimmune conditions like Myasthenia Gravis.

  • Lymphoma: Cancer of the lymph nodes (e.g., Hodgkin lymphoma, Non-Hodgkin lymphoma). This is one of the most common mediastinal malignancies.

  • Germ Cell Tumours: These arise from cells that would normally develop into sperm or eggs. They can be benign (e.g., mature teratoma) or malignant (e.g., seminoma, non-seminomatous germ cell tumours). More common in young men.

  • Thyroid masses (e.g., goiter extending into the chest).

• Middle Mediastinum:

  • Lymphoma.

  • Metastatic cancer (spread from other organs like the lung).

  • Pericardial cysts (benign fluid-filled sacs around the heart).

  • Bronchogenic cysts (benign cysts arising from airway tissue).

• Posterior Mediastinum:

  • Neurogenic Tumours: Tumours arising from nerve tissue (e.g., schwannoma, neurofibroma, ganglioneuroma – often benign; neuroblastoma, ganglioneuroblastoma – often malignant, more common in children). These are the most common posterior mediastinal tumours.

  • Esophageal tumours.

  • Bronchogenic cysts.

  • Lymphoma.
     

What are the Symptoms?
 

About one-third to one-half of people with mediastinal tumours have no symptoms, and the tumour is found incidentally on an imaging test done for another reason.
 

When symptoms do occur, they are often due to the tumour pressing on or invading nearby structures. Symptoms can include:

• Cough (often dry and persistent).

• Shortness of breath or difficulty breathing.

• Chest pain or discomfort (can be dull, sharp, or a feeling of pressure).

• Hoarseness or voice changes (if the nerve to the voice box is affected).

• Difficulty swallowing (dysphagia) (if the esophagus is compressed).

• Wheezing or stridor (a high-pitched breathing sound).

• Swelling of the face, neck, and arms (Superior Vena Cava Syndrome - SVCS): If a large vein called the superior vena cava is compressed. This is a serious sign.

• Horner's Syndrome: Drooping eyelid, constricted pupil, decreased sweating on one side of the face (if certain nerves are affected).

• Systemic symptoms (more common with malignant tumours or specific conditions):

  • Fever, night sweats, unexplained weight loss (common with lymphoma).

  • Muscle weakness (e.g., in Myasthenia Gravis associated with thymoma).

  • Hormonal symptoms (rare, with some germ cell tumours or endocrine tumours).
     

How are Mediastinal Tumours Diagnosed?
 

1. Medical History and Physical Examination: Your doctor will ask about your symptoms, medical history, and family history. A thorough physical examination will be performed.

2. Imaging Tests:

   • Chest X-ray: Often the first test that shows an abnormal shadow or widening of the mediastinum.

   • CT Scan (Computed Tomography): This is a key imaging test. It provides detailed cross-sectional images, showing the exact location, size, shape, and characteristics of the tumour, and its relationship to surrounding structures. Contrast dye is usually given.

   • MRI Scan (Magnetic Resonance Imaging): Can be very useful for further characterising tumours, especially neurogenic tumours or when assessing invasion into blood vessels or the spinal canal.

   • PET Scan (Positron Emission Tomography): Often combined with a CT scan (PET-CT). This scan can help determine if a tumour is cancerous, how active it is, if it has spread (staging), and can be used to monitor response to treatment.

   • Ultrasound (Endobronchial - EBUS, or Endoscopic - EUS): Specialized ultrasound probes on the end of a flexible scope can be passed down the airway (EBUS) or esophagus (EUS) to view and biopsy lymph nodes or masses in the mediastinum.

   • Octreotide Scan or MIBG Scan: Specialised scans sometimes used for neuroendocrine tumours.

3. Blood Tests:

   • General blood tests to assess overall health.

   • Tumour markers: Specific substances that can be elevated in the blood with certain tumours (e.g., Alpha-fetoprotein (AFP) and Human Chorionic Gonadotropin (hCG) for germ cell tumours; antibodies for Myasthenia Gravis with thymoma).

4. Biopsy: A biopsy is almost always needed to get a definitive diagnosis, determining if the tumour is benign or malignant and its specific type. The way a biopsy is obtained depends on the location and accessibility of the tumour:

   • Needle Biopsy (Image-Guided): A thin needle is inserted through the chest wall into the tumour under CT or ultrasound guidance to obtain a tissue sample.

   • Endobronchial Ultrasound (EBUS)-guided Transbronchial Needle Aspiration (TBNA): A bronchoscope with an ultrasound probe is used to guide a needle through the airway wall into the tumour or lymph nodes.

   • Endoscopic Ultrasound (EUS)-guided Fine Needle Aspiration (FNA): An endoscope with an ultrasound probe is passed down the esophagus to guide a needle into nearby mediastinal masses.

   • Mediastinoscopy: A surgical procedure where a small incision is made at the base of the neck. A thin, lighted tube (mediastinoscope) is inserted behind the sternum to view and biopsy tumours or lymph nodes in the anterior and middle mediastinum. Performed under general anaesthesia.

   • Video-Assisted Thoracoscopic Surgery (VATS): A keyhole surgical procedure where small incisions are made in the chest. A camera and instruments are used to biopsy or sometimes remove the tumour. Performed under general anaesthesia.

   • Thoracotomy (Open Surgery): A larger surgical incision may be needed for biopsy if other methods are not feasible or if complete removal is planned at the same time.
      

How are Mediastinal Tumours Managed?
 

Treatment depends on many factors, including:

• The specific type of tumour (benign or malignant, and its subtype).

• The stage of the cancer (if malignant), meaning its size and whether it has spread.

• The location of the tumour and whether it's affecting nearby structures.

• Your overall health and preferences.
   

A Multidisciplinary Team (MDT) of specialists (including thoracic surgeons, oncologists, radiation oncologists, pathologists, radiologists) will discuss your case and recommend the best treatment plan.
 

1. Surgery
 

Surgery is a common treatment, especially for:

• Most benign mediastinal tumours: Surgical removal is often curative and prevents them from growing and causing symptoms.

• Many primary malignant mediastinal tumours: Such as thymomas, thymic carcinomas, resectable germ cell tumours, and neurogenic tumours. The goal is complete removal of the tumour, sometimes with surrounding tissue or lymph nodes.

• Diagnostic purposes: As mentioned (VATS, mediastinoscopy, thoracotomy) when a biopsy is needed and sometimes the entire tumour can be removed at the same time if it's small and appears benign or well-localised.
   

The surgical approach depends on the tumour's location, size, and type:

• Minimally Invasive Surgery (VATS or Robotic-Assisted Thoracic Surgery - RATS): Often preferred for smaller, accessible tumours. Involves small incisions, leading to quicker recovery.

• Mediastinoscopy: Primarily for biopsy, but some small anterior tumours can be removed this way.

• Sternotomy: An incision through the sternum (breastbone). Often used for large anterior mediastinal tumours (e.g., large thymomas) or those involving structures on both sides.

• Thoracotomy: An incision on the side of the chest between the ribs. Used for tumours in the middle or posterior mediastinum, or if VATS is not suitable.
   

2. Radiotherapy (Radiation Therapy)
 

Radiotherapy uses high-energy rays to kill cancer cells or stop them from growing. It may be used:

• As the primary treatment: For some cancers like lymphoma, or for tumours that cannot be surgically removed.

• After surgery (Adjuvant Radiotherapy): To kill any remaining cancer cells and reduce the risk of recurrence (e.g., for some thymomas, thymic carcinomas, or incompletely resected tumours).

• Before surgery (Neoadjuvant Radiotherapy): Sometimes used to shrink a tumour to make it easier to remove.

• Palliative Radiotherapy: To relieve symptoms (e.g., pain, airway obstruction, SVCS) if the cancer is advanced or has recurred.
   

3. Chemotherapy
 

Chemotherapy uses anti-cancer drugs to kill cancer cells. It is often the main treatment for:

• Lymphomas.

• Malignant Germ Cell Tumours.

• Leukemias that may involve the mediastinum.

• Metastatic cancer that has spread to the mediastinum.
   

Chemotherapy may also be used:

• Before surgery (Neoadjuvant Chemotherapy): To shrink tumours like germ cell tumours or some sarcomas.

• After surgery (Adjuvant Chemotherapy): To reduce the risk of recurrence for certain cancers.

• In combination with radiotherapy (Chemoradiotherapy).
   

4. Other Treatments
 

• Hormone Therapy: For certain types of tumours.

• Targeted Therapy and Immunotherapy: These are newer treatments that are becoming options for specific types of cancers, and their role in mediastinal tumours is an active area of research.

• Watchful Waiting (Observation): For some small, clearly benign tumours that are not causing symptoms, regular monitoring with imaging may be an option instead of immediate removal.

• Treatment for Associated Conditions: E.g., treatment for Myasthenia Gravis if present with a thymoma.
   

What to Expect (General Points)
 

• Before Treatment: A thorough evaluation and discussion with your MDT. You'll understand the diagnosis, treatment plan, goals, benefits, and potential side effects.

• During Treatment: This will depend on the chosen therapy. Surgery involves a hospital stay. Chemotherapy and radiotherapy are often outpatient treatments over weeks or months.

• After Treatment: Regular follow-up is essential.
   

Recovery and Follow-Up
 

• After Surgery: Recovery time varies significantly depending on the type of surgery. Pain management, wound care, and physiotherapy (especially breathing exercises) are important.

• Follow-up Care: Essential for monitoring for recurrence or late side effects. This involves regular clinic visits, physical exams, blood tests, and imaging scans (CT, PET-CT, X-ray) for many years.

• Managing Side Effects: Your team will help you manage any short-term or long-term side effects of treatment.
   

When to Contact Your Doctor
 

Contact your doctor or specialist nurse if you experience:

• New or worsening symptoms (e.g., cough, shortness of breath, chest pain, difficulty swallowing).

• Signs of infection after surgery (fever, redness/swelling at wound site).

• Significant side effects from chemotherapy or radiotherapy.

• Any new lumps or swellings.

• Unexplained weight loss, persistent fatigue, or night sweats.
   

Support
 

A diagnosis of a mediastinal tumour can be worrying. It's important to seek support from your healthcare team, family, friends, and patient support organizations. They can provide information, emotional support, and practical help.
 

Disclaimer: This information sheet provides general guidance and is not a substitute for professional medical advice, diagnosis, or treatment. The management of mediastinal tumours is complex and depends on your individual circumstances. Always discuss your specific condition, treatment options, risks, and benefits thoroughly with your medical team.