Learning About Congenital Pulmonary Airway Malformation (CPAM)

Congenital pulmonary airway malformation (CPAM) is a rare lung condition. It happens when a baby’s airways and lungs do not develop the way they should before birth. The baby's lungs form with cysts and other abnormal areas of lung tissue. A cyst is a closed, sac-shaped pocket of tissue.

CPAM is more common in male babies. It used to be called congenital cystic adenomatoid malformation (CCAM).

CPAM may cause breathing problems for a baby before or after they are born. It depends on the size of the cysts. In some cases, the cysts go away before birth.

Sometimes CPAM can lead to serious health conditions. These include a collapsed lung (pneumothorax), cancer, and fetal hydrops. With hydrops, fluid builds up and can cause swelling around a baby’s heart or lungs. But this is rare.

With treatment, most children with CPAM lead normal lives. It very rarely leads to death.

There are five types of CPAM. In each, cysts and other abnormal areas of tissue can form in the lungs.

The types vary by the size, location, appearance, and number of cysts. The cysts can range in size from tiny to large. There may be many smaller cysts or one or more larger cysts. They can be filled with air, liquid, or both. The cysts are usually in one lung, but they can sometimes be in both lungs.

The types are:

• Type 0. This type has tiny cysts (less than 0.5 cm). The cysts affect the entire lung. This is a very rare type. It always causes death.
• Type 1. This type has one or more larger cysts (2 to 10 cm). The walls of the cysts are thin. This type is the most common. About 60% to 70% of CPAM cases are type 1.
• Type 2. This type has small to medium cysts (0.5 to 2 cm). It may also have areas of solid, abnormal tissue.
• Type 3. This type is made up of many tiny cysts (less than 0.5 cm). It may also have areas of solid, abnormal tissue.
• Type 4. This type has one or more medium to large cysts (less than 7 cm). The walls of the cysts are thin.

Doctors don’t know what causes CPAM. It may be caused by the airways in a baby’s lungs not growing as they should before birth. Or the airways may stop developing too early before birth.

CPAM is not caused by anything you did or didn’t do during pregnancy. And it’s likely not passed down through the family.

The symptoms can depend on the type of CPAM an infant or older child has. Symptoms may include:

• Signs of respiratory distress, such as:
  • Rapid breathing (tachypnea).
  • Bluish skin or lips.
• A respiratory tract infection, like pneumonia, that keeps coming back (recurring).
• A cough and fever.
• Shortness of breath (dyspnea).

Signs of respiratory distress are usually the main symptom in infants. A cough and fever usually happen in children older than 1 year. Some babies have no symptoms at birth. And some children may go through childhood without having any symptoms.

CPAM may be diagnosed before birth or during childhood. It’s often found with an ultrasound in the second trimester of pregnancy. This may happen during a routine prenatal checkup.

Before birth your doctor may use an MRI to find out what type of CPAM your baby has. You may also have an MRI to check your baby for other health conditions that can look like CPAM.

If a newborn or an older child has symptoms, an imaging test is used to diagnose CPAM. This could be a standard X-ray, a CT scan, or an MRI of the chest.

If CPAM is diagnosed before birth, you will likely have weekly ultrasounds to monitor your baby’s condition. Your delivery may be planned for a special hospital where your baby can have surgery right away, if needed. You may have a C-section. In some cases, a baby may be delivered early.

Your baby will have a chest X-ray soon after birth. This is to confirm that your baby has CPAM and to see how your baby’s lungs are doing. A CT scan or MRI may also be done after birth. These can find out the size of the cysts and other abnormal tissue. Depending on your baby’s symptoms and size, an MRI or a CT scan may be done right away. Or it may be done within 6 months of birth.

Most cases of CPAM in an infant are treated with surgery to remove the cysts. The surgery may be done right away or later when a baby is older. It depends on a baby’s symptoms.

If your baby does not have surgery right away, they will be closely watched for problems during their first year. They will likely have an MRI or a CT scan once a year.

You and your baby’s care team may include a maternal-fetal medicine specialist (perinatologist), an obstetrician, a pediatrician, and a surgical team.