What is Swyer-James-MacLeod Syndrome?
Swyer-James-MacLeod syndrome (often shortened to SJMS or known as hyperlucent lung syndrome) is a fairly rare medical condition. This syndrome essentially causes one lung (or part of one lung) to not function properly, and this part of the lung can appear unusually “clear” or “hyperlucent” on X-rays. Sometimes, it could also lead to a lung disease known as emphysema and bronchiectasis – a condition where the airways of the lungs get wider and consequently become flabby and scarred.
The syndrome was first discovered back in the 1950s by three medical professionals: William Mathieson Macleod, a respiratory physician from England, and Paul Robert Swyer and George James, both from Canada. Macleod identified it in 1954, while Swyer and James spotted it in 1953 – hence the name of the syndrome.
In terms of what causes SJMS, it’s believed to develop after a person, usually a child, experiences a particular type of lung disease known as bronchiolitis obliterans. In summary, despite its rarity, SJMS is an important condition to recognize due to its impact on lung function.
What Causes Swyer-James-MacLeod Syndrome?
Swyer-James-MacLeod syndrome was originally believed to be present from birth, due to an underdeveloped lung artery. However, the exact cause of this condition is still unknown. It’s now widely understood that this is a rare outcome of certain respiratory infections in childhood, most commonly bronchiolitis obliterans or pneumonitis which are forms of lung diseases.
Recurring lung infections caused by specific viruses or bacteria are known to trigger this condition. These include various types, like the measles virus, respiratory syncytial virus (a common cause of lung infections in children), influenza A virus, Paramyxovirus morbillivirus (a virus group that includes measles and mumps), and adenovirus types 3, 7, and 21 (common types that affect the respiratory tract). Bacterial agents include Bordetella pertussis (responsible for whooping cough), Mycobacterium tuberculosis (which causes tuberculosis), and Mycoplasma pneumoniae (causes a type of mild pneumonia).
Risk Factors and Frequency for Swyer-James-MacLeod Syndrome
Swyer-James-MacLeod syndrome is a rare medical condition that’s not well-understood due to its infrequency. Since it was first identified in 1953, most of the information we have comes from individual case studies. An example of this is a single study that found the syndrome in 0.01% of almost 17,500 chest X-rays reviewed. Because it’s challenging to diagnose, many cases are overlooked or confused with illnesses like asthma or bronchiectasis.
- It’s hard to diagnose Swyer-James-MacLeod syndrome, leading to many cases remaining unidentified or being diagnosed as different illnesses.
- One study found the syndrome in 0.01% of nearly 17,500 chest X-rays reviewed.
- About 4% of patients with a condition called bronchiolitis obliterans also have this syndrome.
- For reasons that aren’t yet clear, the left lung tends to be affected more than the right one in most patients with this syndrome.
Signs and Symptoms of Swyer-James-MacLeod Syndrome
Swyer-James-MacLeod syndrome is a rare condition that can sometimes be hard to diagnose because it often appears like other lung-related conditions. Many people with this syndrome show no symptoms, while others may have repeated lung infections. The syndrome can be found at any age, sometimes only discovered by accident when medical tests are being done for other reasons. Symptoms, when present, often include repeated lung infections or shortness of breath during exercise.
- Repeated lung infections
- Shortness of breath during exercise
- Wheezing
- Reduced ability to exercise
- Coughing (sometimes with blood)
- Chest pain
Physical signs of the syndrome can include a smaller range of movement in the chest, a ‘hollow’ sound when the chest is tapped, and quieter breathing sounds on the side affected. In some people, the mediastinum (the area between the lungs) may shift towards the side of the body affected, which may also shift the point where the heartbeat can be felt.
Testing for Swyer-James-MacLeod Syndrome
Swyer-James-MacLeod syndrome can show itself in a variety of ways, and because it’s rare, there aren’t any set guidelines for how to diagnose it.
Usually, the first step is to get a type of X-ray called a posteroanterior chest radiograph. This can show signs like fewer blood vessels in the lung, a small shadow near the center of the chest, and a segment or lobe of the lung looking unusually bright. These signs are most noticeable when you exhale, as the lung doesn’t fully deflate, causing the muscle under your lungs (diaphragm) on the affected side to rise less. On an exhale, the difference in brightness between the normal lung and the affected one becomes even more apparent. The central area of the chest (mediastinum) may also shift towards the side with the affected lung, but will move towards the normal lung as you exhale.
After that, a computed tomography (CT) scan of your chest is typically the next step. This can help assess the full extent and spread of the disease. It can show signs like emphysema (a lung disease that damages your air sacs), bullae (air spaces that form in the lung), bronchiectasis (damage to the airways), atelectasis (collapsed lung), and scars. Studies have shown that a CT scan can detect the syndrome much better than just an x-ray, as it often shows that both lungs are affected and that the changes are not evenly distributed. The scan should also include some images taken while you exhale to clearly show trapped air. About 30% of people with Swyer-James-MacLeod syndrome have bronchiectasis, which can either be cylindrical or saccular. It’s important to tell which type it is, as people with saccular bronchiectasis have more severe flare-ups and worse outcomes. If your doctor thinks you might have bronchiectasis based on your symptoms, they will recommend a high-resolution CT scan of your chest. This is to make sure your diagnosis is accurate and to correctly differentiate between the two types.
A ventilation/perfusion scan, which compares airflow and blood flow in your lungs, can show a defect in airflow and blood flow of the affected area. Some recommend it as the first test after a chest x-ray in evaluating people with suspected Swyer-James-MacLeod syndrome. CT pulmonary angiography is not necessary but can show underdevelopment of the blood vessels in the affected lung or segment.
Lung function tests often show a restrictive pattern in people with Swyer-James-MacLeod syndrome. People with bronchiectasis might have a mixed restrictive-obstructive or even mainly obstructive defect, where the blockage of airflow can’t be relieved with bronchodilators (medication that opens up your airways). The total lung capacity (TLC) could be slightly reduced. Tests for alpha-1 antitrypsin deficiency, a rare inherited lung disease, can help rule out other causes of bronchiectasis/emphysema.
To diagnose Swyer-James-MacLeod syndrome, you need to have at least one of these:
1. Loss of lung volume with the lung appearing unusually bright on only one side, as shown by a chest X-ray
2. Lower amounts of blood vessels on one side, as shown by a CT scan of the chest
3. Loss of blood flow on only one side, as shown by a technetium Tc 99m lung scan
Treatment Options for Swyer-James-MacLeod Syndrome
Swyer-James-MacLeod syndrome is managed by a team of healthcare professionals and the treatment is tailored to the patient’s specific needs. The main treatment is careful management of symptoms, and often a few preventative measures are implemented.
One preventative measure is giving vaccines against infections like pneumococcus and flu, since these can be particularly harmful for people with this syndrome. For patients who have bronchiectasis, a lung condition that causes coughing and breathing problems, medications that thin mucus can be beneficial. Techniques like percussion and postural drainage can also be used to clear out mucus from the lungs. Medications like corticosteroids and inhaled bronchodilators may also be used to open up the airways and reduce inflammation. In cases where the lung’s ability to get enough oxygen becomes compromised, long-term oxygen therapy might be required. Patients might also be referred to specialized exercise programs designed to improve lung function.
Surgery might be considered for some patients. Usually, it’s considered if they frequently get lung infections, if their symptoms don’t get better with medications, or if they can’t control symptoms even with the best medical treatment. Surgical options can include removing the lung or reducing lung volume by removing a part of the lung. These surgeries often improve symptoms and lung function with little side effect. Some people might also benefit from a newer surgical approach where the main airway to the lung is blocked but the lung is kept in place. This approach is less invasive and would prevent the other lung from moving into the space left behind by the reduction or removal of the affected lung. This surgery would also include frequent cleanings of the airway along with broad-spectrum antibiotics to prevent an infection. Two years after the surgery, the treated lung is expected to have fibroatelectasis, a condition where the lung shrinks and becomes scarred, and any inflammation should dissolve.
Remember, the strategy of blocking the airway to the lung is mainly used in Swyer-James-MacLeod patients as the affected lung does not have blood flow. If this process were to happen in a healthy lung, it could cause a harmful condition known as right to left shunt, which could lead to low oxygen levels in the body.
What else can Swyer-James-MacLeod Syndrome be?
Swyer-James-MacLeod syndrome can sometimes be mistaken for other conditions that make one lung appear more prominent or inflated than the other. This can happen for a number of reasons, such as a decrease in blood flow to the lung or the air sacs in the lung becoming over-inflated. It is often confused with both congenital (present at birth) and acquired lung disorders.
Consider an ailment known as Congenital Lobar Emphysema (CLE). This is a condition where a baby’s lung develops unusually, resulting in an over-expansion of air sacs within one or more lobes of the lungs. This disorder mainly arises due to various abnormalities in the development of the respiratory system. Air might get trapped in the lungs and cause a specific portion of it to inflate more, because the inflowing air during inhalation is more than the outgoing air during exhalation. This is referred to as the “ball-valve” mechanism. The symptoms often include a swollen lobe, the heart and nearby lungs getting squashed against one side, and a flattened diaphragm because of an over-inflated lung.
Another condition, Localized Pulmonary Interstitial Emphysema, is quite similar to CLE, but it can occur from complications of mechanical ventilation in infants. It can also be caused by a blockage in the lung’s airways either from a foreign body, a mass (such as a rare type of cyst, part of the lung developing improperly, malformation in the airway of the lungs, hernia in the diaphragm, or changes in the lung artery), or the collapse of the airway, which can happen if it’s unusually weak or thin.
Additional factors to consider include abnormalities in lung development including cases where part of a lung, its airways, or blood vessels don’t form properly. This could result in one side of the lung inflating more which can look like Swyer-James-MacLeod syndrome on a chest x-ray.
Other conditions such as Poland syndrome, which affects the chest wall and can lead to an unusual appearance of the chest on an x-ray, may also be mistaken for Swyer-James-MacLeod syndrome.
Lastly, in severe cases, Swyer-James-MacLeod syndrome may be mistaken for a collapsed lung, where air leaks into the space between the lung and chest wall.
In all these cases, it’s crucial to examine both the x-ray and computed tomography (CT) scan of the chest, as well as a clinical assessment, to ensure the correct diagnosis is made and unnecessary treatments are avoided.
What to expect with Swyer-James-MacLeod Syndrome
People with Swyer-James-MacLeod syndrome (SJMS) typically live a normal lifespan. The actual symptoms of SJMS can vary from person to person. However, the majority of a patient’s experience depends on whether they have a condition called bronchiectasis.
Bronchiectasis is a disease that causes permanent enlargement of parts of the airways of the lung. Cylindrical bronchiectasis resembles a tube, while saccular bronchiectasis resembles a sac or small bag.
A person with SJMS who doesn’t have bronchiectasis or who only has the cylindrical type often experiences mild respiratory symptoms, which tend to get better on their own over time. However, if a person has the saccular type of bronchiectasis, they often experience recurrent cases of pneumonia – a lung infection. These individuals are at a higher risk of needing surgical intervention.
Possible Complications When Diagnosed with Swyer-James-MacLeod Syndrome
The main problem with SJMS is that patients might develop a serious lung condition called bronchiectasis that can cause a chronic cough and make them more vulnerable to lung infections. Additionally, the development of air-filled spaces in the lungs (known as bullae) can increase the risk of a collapsed lung and limit their activities like diving and air travel. It’s also possible for SJMS patients to have lung abscesses.
Over time, lung function can gradually deteriorate, leading to type I respiratory failure that necessitates long-term oxygen therapy. This can seriously impact a person’s independence and overall quality of life.
Lastly, patients who undergo surgical operations risk experiencing complications, including infection at the surgical site, nerve damage, and emphysema, which is a condition that causes shortness of breath. However, such risks are minimal and, to date, there have been no reported cases of patients experiencing negative health effects as a result of the surgery. In fact, their lung function has significantly improved.
Common Complications:
- Bronchiectasis
- Chronic cough
- Increased susceptibility to lung infections
- Risk of collapsed lung
- Restrictions on activities like diving and air travel
- Lung abscess
- Type I respiratory failure
- Need for long-term oxygen therapy
- Decreased independence and quality of life
- Infection at surgical site
- Nerve damage
- Pneumothorax (collapsed lung)
- Emphysema
Preventing Swyer-James-MacLeod Syndrome
Your doctor should explain to you about SJMS, a condition that’s caused by infections during childhood. This means it is not inherited or genetic – you didn’t get it from your parents, and your children will not get it from you. Therefore, it won’t affect your plans to have a family.
Remember, it’s not your fault that you have this condition. There was nothing you could have done to avoid getting it.
You are encouraged to stop smoking to protect your lungs from getting worse. This is especially crucial for avoiding further lung damage, making existing lung conditions like emphysema worse, and preventing the development of chronic obstructive pulmonary disease, a long-term condition that makes it difficult to breathe.
Your doctor will provide you with information on spotting early signs of lung infections and will give you a supply of antibiotics for quick treatment at home. Early treatment of these infections is very important. It’s also crucial to get the flu shot and the pneumococcal vaccine to protect against other lung infections. During your check-up visits, your doctor will check how well you’re using your inhaler and if you’re taking your medication regularly. You’ll also be given the contact information of a community nurse for further support at home.
Finally, your doctor should refer you to a specialist for chest physiotherapy and teach you the importance of regular exercises to cleanse your lungs. Following these exercise regimens is quite crucial.
