Mediastinum and windpipe

What are these?

The mediastinum is the space in the middle of the chest, between the two lungs. MedlinePlus writes that the heart, large blood vessels, windpipe, thymus, oesophagus and connective tissue lie in it, and divide it into front, middle and back parts.

A mediastinal mass or tumour grows in this space. MedlinePlus calls it rare and says that in children it is seen mostly in the back part, often starts from a nerve and is benign. In adults it is mostly in the front part and is usually malignant: lymphoma, germ cell tumour or thymoma, mostly seen in middle-aged and older people. The same source says nearly half of these masses cause no symptoms and are found by chance when a chest X-ray is taken for another reason. When there are symptoms, they come from pressure on nearby organs: chest pain, cough, coughing up blood, hoarseness, fever and chills, night sweats and breathlessness.

The thymus is a gland in the front of the chest. The NHS says myasthenia gravis, a rare long-term condition that causes muscle weakness, is known to be linked to a problem of the thymus, and many patients have an enlarged thymus. About one in ten patients has a thymoma, an abnormal growth in the thymus. Its symptoms are drooping eyelids, double vision, difficulty chewing, swallowing and speaking clearly, weakness of the arms, legs and neck, and sometimes breathlessness; it is usually worse when tired.

Tracheal stenosis means narrowing of the windpipe. Cleveland Clinic writes that the cause is inflammation or scar tissue inside the windpipe. The most common cause of the acquired type is a long period with a breathing tube (intubation). Other causes include autoimmune diseases, infections such as tuberculosis, a mass pressing from outside, inhaling chemicals, radiation to the neck or chest, and an earlier tracheostomy. There is also a congenital type, which is rare.

When does someone come to a surgeon?

• A mass seen in the mediastinum on a CT or chest X-ray, where the doctor wants a surgeon’s opinion for a biopsy or a decision about treatment.
• A thymoma, or myasthenia gravis for which the neurologist is considering removal of the thymus. The NHS says removing the thymus is one way to treat myasthenia gravis.
• A narrowing of the windpipe for which stretching or a stent is not enough, or which comes back. Cleveland Clinic counts removing the narrowed section and joining the two ends of the windpipe among the options.

Referral to a surgeon does not mean an operation is certain. For some masses, such as lymphoma, MedlinePlus names targeted therapy and chemotherapy as the preferred treatment.

How is it investigated?

• Chest X-ray and chest CT. MedlinePlus counts these among the tests for a mass.
• Biopsy: a needle guided by CT, or mediastinoscopy with a biopsy (MedlinePlus).
• PET scan (MedlinePlus).
• Blood tests and nerve-muscle tests if myasthenia is suspected; the NHS mentions blood tests, nerve tests and scans.
• For tracheal stenosis: Cleveland Clinic calls bronchoscopy the main way to diagnose it. CT of the chest and neck is the most common imaging. Sometimes an MRI for treatment planning and lung function tests are done too.

How is it treated in general?

Treatment is based on the type of mass. MedlinePlus writes:

• Thymoma: treated with surgery, and depending on the result of the operation and the stage, radiation or chemotherapy may be added.
• Germ cell tumour: usually chemotherapy.
• Lymphoma: targeted therapy and chemotherapy, and perhaps radiation afterwards.
• Nerve tumours of the back part: surgery is the main treatment.

The same source says radiation, surgery and chemotherapy can each have serious side effects, and different tumours respond differently to chemotherapy and radiation. How the surgery is done is the surgeon’s decision, based on the place and type of the mass.

Myasthenia gravis: the NHS describes treatment in three parts: avoiding things that make symptoms worse, such as tiredness and stress; medicine to strengthen the muscles; and surgery to remove the thymus.

Tracheal stenosis (Cleveland Clinic): stretching with a balloon or dilator; laser to remove scar tissue; a stent that holds the windpipe open (which is not always possible); and removing the narrowed section and joining the two healthy ends. Stretching is less invasive and may need to be repeated; removing the narrowed section is more invasive but more likely to resolve the narrowing in the long term. The narrowing may come back after treatment, because the treatment itself can make scar tissue.

What can you do?

• Bring all images and reports with the discs, especially old CT scans, which are useful for comparison.
• Write down your symptoms: when are they worse? When tired? When lying down? Is your voice hoarse? Do you have fever or night sweats?
• If you have a narrowed windpipe, mention any history of a breathing tube or tracheostomy.
• Carry your medicine list. Do not stop any medicine, especially a myasthenia medicine, without telling your doctor.
• Whenever you have new or worse breathlessness, tell your doctor. Cleveland Clinic says to contact a doctor whenever you are short of breath.

When to get urgent help

• Very hard breathing, gasping, being unable to say a sentence, blue lips or sudden confusion. Call 115, Iran’s emergency number (NHS). Cleveland Clinic also says if you cannot breathe, go to the emergency department.
• Myasthenia gravis with a sudden worsening of symptoms, such as severe trouble breathing or swallowing. Call 115, Iran’s emergency number; the NHS says urgent hospital treatment may be needed.
• Coughing up more than a few streaks of blood, or with breathlessness and chest pain. Call 115, Iran’s emergency number (NHS). If it is only a few small streaks of blood, the NHS suggests an urgent doctor’s appointment; in practice, report it the same day.

Do not drive yourself. See the full list in the guide When should I call urgently?