What Are Congenital Lung Malformations?

Though rare, congenital lung malformations can result in parts of the lung and airways not forming normally during prenatal development. Depending on the severity, this might cause significant symptoms or no problems at all.

They are rare conditions, estimated to affect 1 in 10,000 infants born. Some estimates put the number closer to 1 in 3,000, based on new information from sensitive prenatal scans.

Types of Congenital Lung Malformation

The terminology around congenital lung malformations is still in flux, and some conditions are known by more than one name.

One of the more common types is congenital pulmonary airway malformation (CPAM). It is also known as congenital cystic adenoid malformation (CCAM). Some of the other types described are:

• Pulmonary sequestration
• Congenital lobar emphysema (infantile lobar hyperinflation)
• Arteriovenous malformation in the lungs
• Bronchogenic cysts (or other cyst types)
• Congenital small lung
• Agenesis of the lung (absent lung)
• Bronchial atresia (absent bronchus)

Lung Malformation Symptoms

The symptoms of a congenital lung disease might first appear at any age. For example, some infants with a more severe kind of congenital lung disease might show signs of respiratory distress, and they may look like they are having trouble breathing. Other symptoms might include wheezing, blue skin, and difficulty feeding.

A fetus with a very severe kind of congenital lung malformation might show signs of hydrops fetalis on ultrasound. This is an extremely serious condition in which abnormal amounts of fluid build up in one or more organs. If the overall problem is very severe, an affected infant might die shortly after birth.

But sometimes these are minor issues that don’t cause any symptoms at all. The abnormality might only be detected because of an imaging test, perhaps on a prenatal ultrasound or a chest X-ray done in childhood or adulthood. Some such malformations are probably never identified, or only if a person has an autopsy after their death.

There is a lot of variation in the severity and type of symptoms experienced by someone with a congenital lung malformation. Symptoms can vary based on the amount of the respiratory tract involved, the type of malformation, and the specific location of the affected regions. Some potential problems include:

• Cough (potentially bloody)
• Recurrent lung infections
• Hemothorax
• Pneumothorax
• Blue-tinged skin (cyanosis)
• Fatigue
• Shortness of breath
• Clubbing of the fingers
• Heart failure (uncommon)

No definitive evidence support the association between congenital lung malformations and cancer.

Rarely, people with congenital lung disease also have congenital issues that affect other organs, such as the heart or parts of the nervous system.

Causes

The development of the lungs and airways takes place through a complex series of steps during prenatal development. The cells that will become the airways leading down to the lungs and the lungs themselves form in very complicated and coordinated steps. When something interferes with this developmental process, a congenital malformation of the lung can result.

Your lung contains very small pockets within it, called alveoli. This is where oxygen you’ve breathed in from the air enters the blood. Excess carbon dioxide from the blood enters the alveoli and leaves the body as you breathe out. That’s critical, because all cells of your body need oxygen to live, and carbon dioxide can cause problems if it isn’t removed normally.

When the lungs don’t develop normally, it can lead to symptoms and complications. Most importantly, if not enough of the lung can perform its normal function, it’s a life-threatening situation. Fortunately, for many people with congenital lung malformations, enough of the lung is working normally, so the problems aren’t as significant.

Certain genes have been identified that may be involved in causing congenital lung malformations, but a lot of the details on this are still not clear. These abnormalities don’t seem to run in families.

Exposure to certain environmental factors may also play a role. For example, we know that factors such as infection during pregnancy and exposure to certain drugs and chemicals can broadly increase the risk of congenital abnormalities in various organ systems.

However, we still don’t understand much about the issues that might increase the risk of congenital lung malformations. Most of the time, there is no identifiable cause.

Diagnosis

Congenital lung malformations can be diagnosed at any age, including prenatally. This condition is being diagnosed more frequently than in the past, probably because of increases in imaging (both prior to and after birth).

For some perfectly healthy adults, a chest X-ray done for some other reason might be the first they learn that they have a congenital lung malformation.

Medical history and exam provide the important foundations for diagnosis. The healthcare provider asks about recent symptoms and any long-term medical conditions, as well as family medical history. The exam gives important clues about whether the person needs immediate treatment.

It’s important to distinguish other medical problems that might have similar symptoms or imaging findings (like from a lung infection, sarcoidosis, or certain genetic syndromes.) That’s important, because not all these possibilities have the same treatment. It’s also important to see if there are issues with any other organ systems of the body, like the heart.

Medical imaging tests also play a key role. Increasingly, congenital lung malformations are being diagnosed during pregnancy, from detailed anatomic ultrasound scans commonly performed around week 20. If a potential issue is found, a series of ultrasounds can provide information about whether the problem might be going away or worsening.

Tests like fetal echocardiogram may be able to give a sense of whether other organs might be involved as well.

Chest X-ray provides a helpful initial diagnostic tool. However, it’s important to note that chest X-ray does not pick up all kinds of congenital lung malformations. Computerized tomography (CT) of the chest is generally considered the gold standard for diagnosis, as it provides more detailed information than a simple X-ray.

Other imaging tests might be used as well, depending on the circumstances. This might include CT angiography or magnetic resonance imaging (MRI). Bronchoscopy—which lets doctors look inside the pathways of the airways—can also be helpful in some situations.

Basic tests may also be necessary to rule out other causes and get a sense of how severe the problem is, depending on the context. For example, this might include:

• Pulse oximetry
• Arterial blood gas
• Complete blood count
• Tests of blood glucose
• Tests for infection (like blood culture)
• Echocardiogram, to rule out heart problems
• Genetic tests for other health conditions

Treatment

For a fetus diagnosed prenatally, treatment inside the womb is determined after consultation with appropriate specialists. Some infants diagnosed with congenital lung malformations might need stabilizing treatment at birth, if they show signs that their lungs aren’t working well enough. For example, this might include supplementary oxygen or respiratory support on a ventilator or through extracorporeal membrane oxygenation (ECMO).

Surgery

The definitive treatment is surgery, which might be performed soon after birth, several months later, or in later childhood or adulthood. Surgery is usually recommended if a person is experiencing symptoms from their congenital lung malformation, like repeated infections.

Most types of surgery remove the affected area and part of the surrounding tissue. Fortunately, for most people with congenital lung malformations, this leaves enough functioning lung tissue. Depending on the context, more or less of the lung might need to be removed.

For example, a wedge resection removes only a small portion of the lung. In a lobectomy, the surgeon removes a larger section, a lung lobe (one of the three of the right lung or one of two on the left). The most invasive approach is a pneumonectomy, which involves removing an entire lung.

Often it is possible to use a minimally invasive type of surgery, such as video-assisted thoracoscopic surgery (VATS). Such approaches can use smaller incisions compared to an open surgery.

When There Aren’t Symptoms

Most infants who have been diagnosed with potential congenital lung malformations are born without complications and don’t have any symptoms at birth. And some older people are first diagnosed later, like from an imaging study, but don’t have any symptoms.

If it is decided not to surgically remove a congenital lung malformation, many practitioners recommend repeated imaging scans to monitor for potential development of a cancer.



A Word From Verywell

Congenital lung malformations are an uncommon medical problem, but one that can be particularly frightening for expectant parents. Fortunately, most of these babies will do very well, and professionals are there to provide support and treatment if needed. Work with your medical team to figure out a management plan that makes sense for your family.