Cystic Lung Diseases: What You Need to Know About Pulmonary Cysts

Cystic lung diseases develop when sacs filled with liquid or air (cysts) form in the lungs, sometimes causing pain. There are several conditions that fall under the broader category of cystic lung disease, including lymphangioleiomyomatosis (known as LAM), pulmonary Langerhans cell histiocytosis (PLCH), lymphoid interstitial pneumonia (LIP), and Birt-Hogg-Dubé (BHD) syndrome. 

This article discusses the types of cystic lung disease and treatment options for these diseases.

What Causes Pulmonary Cysts? 

There are several types of lung diseases that cause pulmonary cysts, also known as lung cysts. One of the most common reasons lung cysts develop is because air gets trapped in the lungs.

Other common causes of pulmonary cysts include:

• Restriction of blood flow to the lungs
• Remodeling of lung tissue induced by certain proteins and enzymes within the body
• Genetic mutations  
• Smoking
• Infections
• Issues with immune system functions
• Tumor growths

Types of Cystic Lung Disease

There are four main types of cystic lung diseases.

Lymphangioleiomyomatosis (LAM)

LAM is a rare type of cystic lung disease that can affect the lungs, kidneys, and the lymphatic system. The group most affected by LAM is women of childbearing age.

LAM develops because cells that mimic muscles begin to grow uncontrollably within the lungs, kidneys, and lymph nodes. LAM can be passed on through families having the genetic disease known as tuberous sclerosis complex (TSC).

The main symptoms associated with LAM include:

• Tiredness or fatigue
• Chronic cough
• Shortness of breath
  

Pulmonary Langerhans Cell Histiocytosis (PLCH)

While the exact cause of PLCH isn’t entirely understood, it may be brought on by cigarette smoking. Smoking is associated with PLCH because cigarette smoke has the ability to activate specific cells known as Langerhans cells.

In normal circumstances, these cells are designed to help regulate immune function. In PLCH, these cells get activated in the lungs when they aren’t needed and cause changes within the structure of the lungs that lead to cyst development.

This type of cystic lung disease tends to affect adults under the age of 40. Symptoms include:

• Shortness of breath
• Weight loss that can’t be attributed to anything else
• Fever
• Coughing
• Skin rashes
• Bone lesions
• Lung collapse

Birt-Hogg-Dubé (BHD) Syndrome

BHD is a type of cystic lung disease that can affect the lungs and the skin. This rare disorder can also increase the risk of developing specific types of tumors over the course of a person’s lifetime.

BHD typically first develops when a person is between 20 and 40 years old. The most common symptom is small noncancerous tumors forming on the face, neck, and upper chest area. The tumors then begin to grow larger and multiply, causing an increased risk of lung collapse and kidney tumors.

The condition is caused by mutations in a specific type of gene known as the FLCN gene. FLCN is the gene that provides the information needed to create folliculin, which is a type of protein thought to suppress tumor formation in the body.

Lymphoid Interstitial Pneumonia (LIP)

Lymphoid interstitial pneumonia (LIP) is a form of lung disease that typically affects adults between the ages of 40 and 70.

While the condition can develop without an underlying disorder, it has been most notably associated with the following:

• Human immunodeficiency virus (HIV)
• Rheumatoid arthritis
• Systemic lupus erythematosus
• Sjögren’s syndrome

Alongside lung cysts that occur in both lungs, other symptoms that can develop include:

• Shortness of breath
• Fever
• Weight loss that isn’t attributed to anything else
• Cough
• Lung collapse

Diagnosis

Diagnosing cystic lung disease can be complicated because there are many types of diseases and varying causes. Typically, the diagnostic process will involve a collection of health history and symptoms, along with certain lifestyle information.

Some examinations that may take place to diagnose cystic lung disease include:

• Computed tomography (CT) scans: A CT scan is a type of X-ray imaging test that can be used to determine where the lung cysts have accumulated.
• Lung biopsies: Lung biopsies require removing a sample of tissue to be examined in a lab. They are usually a follow-up test if a proper diagnosis cannot be formed through CT alone.
• Microscopic hematoxylin-eosin staining: This type of exam uses a special stain to help determine the shape and structure of cysts within the lungs.
• Blood tests: In some cases, certain markers within the blood can help determine if a person has cystic lung disease so blood tests will also be taken.

Treatment

Treating cystic lung disease depends on the underlying cause. Treatments for each type of cystic lung disease include:

• LAM: Medications designed to control the growth of LAM cells, machines such as bronchodilators that help a person breathe better, and oxygen therapy can all be used as part of LAM treatment. However, a lung transplant may be necessary to cure the disease.
• PLCH: The first treatment guidance given to people with PLCH is to quit smoking. Typically, the lungs can recover from PLCH if a person does this quickly. Other treatments include corticosteroids to reduce inflammation and some cancer medications, although they aren’t always effective. Lung transplants can also be considered in more severe cases.
• BHD: There isn’t a typical treatment option available for BHD because of its rarity. Typically, tumor growths on the skin can be removed, and if the lungs are affected, surgery to eliminate fluid buildup in the lungs can be performed.
• LIP: There is no current treatment option that works for everyone with LIP. Possible options can include corticosteroids or immunosuppressive medications, although treatment will highly revolve around the underlying cause.

When to See a Healthcare Provider

There are several screening options available for people who may be at higher risk of developing cystic lung disease due to genetic factors. If that's the case for you, you should see your healthcare provider about getting regular chest exams so that you can catch any cysts that develop early on.

Regardless of whether you have a hereditary or genetic component, you should see your healthcare provider if you experience any symptoms of cystic lung disease, such as shortness of breath, a new or chronic cough, and weight loss that isn’t tied to new lifestyle changes.

Summary

Cystic lung diseases occur when cysts form on the lungs. There are various types of cystic lung diseases, each with its own causes and symptoms. These conditions include lymphangioleiomyomatosis, pulmonary Langerhans cell histiocytosis, lymphoid interstitial pneumonia, and Birt-Hogg-Dubé syndrome. While these types of diseases are rare, they can lead to serious complications such as lung collapse.

If you experience any of the symptoms, such as shortness of breath or unexplained weight loss, contact your healthcare provider. Your provider will order tests to determine if there are cysts on your lungs and what the cause of the symptoms may be. While there are viable treatments available for each type, the most effective is a lung transplant.

A Word From Verywell 

Cystic lung diseases can often go unnoticed because they don’t always present with symptoms, and, in some cases, symptoms may seem unrelated to lung health. If you think you may be at an increased risk of lung problems, request regular chest screenings from your healthcare provider. Catching cystic lung disease can help you to avoid more serious complications.