Airway, Breathing and Lung Conditions

Congenital Lung Malformations

What are congenital lung malformations?

The name “congenital lung malformations” covers a broad range of lung problems. Some are cysts (abnormal closed sacs inside the body that contain fluid or gas). Others are solid growths or are mixed (part cyst, part solid). Congenital lung problems form while a baby’s lungs are developing in the womb.

Another lung problem sometimes grouped with lung cysts is congenital lobular emphysema (pronounced em-fizz-EE-muh). With this condition, the airway to 1 lobe (section) of the lung is blocked. Air becomes trapped in this lobe, making it expand. It may expand so much that it presses on the healthy lobes or the other lung.

    • Congenital cystic adenomatoid (pronounced add-en-OH-muh-toyd) malformations (CCAMs): These malformations form when some of a baby’s lung tissue grows more than it should. The growth may cause cysts, which are filled with fluid and range in size from very small to very large. CCAMs may prevent some of the tiny air sacs (alveoli) in the lungs from developing normally. A baby may have 1 or more CCAMs. Most babies with CCAMs have them in only 1 section (lobe) of a lung.
    • Pulmonary sequestrations (pronounced PULL-muh-nair-ee see-ques-TRAY-shuns) (PSs): These are solid masses of lung tissue. They are usually closed off from the rest of the lung and don’t connect to the normal airways or normal blood supply. They may be inside the lungs (intralobular) or outside the lungs (extralobular) in the chest or belly. (PSs are also called bronchopulmonary sequestrations or BPSs.)

    These types of malformations form in similar ways. Some children have cysts or masses that seem to be a cross between the 2 types. Sometimes these conditions are grouped under 1 name – congenital pulmonary adenomatoid malformations (CPAMs).

Congenital lung malformations in children

The effects of congenital lung malformations depend on their size and location. Some lung malformations, mainly small ones, have no effects. Others have such serious effects that they threaten the life of a baby even before birth and may need to be treated while the baby is still in the womb.

One main concern is that a large malformation takes up space in your baby’s chest. It may keep the lung on the same side from reaching a normal size, called pulmonary hypoplasia. It may even push on the lung on the other side or on structures in the space between the lungs, called mediastinum. These structures include the airways, the heart and the swallowing tube to the stomach (esophagus).

Another concern is that too much blood may flow to your baby’s CCAM. This can cause congenital heart failure and lead to hydrops, which can be fatal for a baby. Hydrops is a buildup of fluid in a baby’s body that can cause swelling, heart problems, breathing problems and other symptoms. If doctors detect hydrops at a certain stage of development, they may be able to treat it before birth with medicines called corticosteroids.

Congenital Lung Malformations at Seattle Children’s

We have treated many children with congenital lung malformations at Seattle Children’s. The team from our Prenatal Diagnosis and Treatment Program has the expertise to monitor babies with malformations that are found before birth and provide prenatal treatment.

  • We focus on how today’s treatments will affect your child as they develop and become adults. We base treatment plans on years of experience and the newest research on what works best – and most safely – for children and teens. This experience helps us easily diagnose your child’s condition and work with you to decide on the best treatment.

    Our doctors are experienced in performing the surgeries needed to remove the lung malformations after birth. For patients with severe breathing problems, we have an Extracorporeal Life Support Program. Our Surgery Pulmonary Follow-Up Clinic helps your child be as healthy as possible after surgery.

  • At Seattle Children’s, your family has a full team behind you, from diagnosis through treatment and follow-up. From our appointment schedulers to our pediatric nurses, our team is specially trained to work with children and their families. Our facilities and equipment also reflect this kid-friendly, family-centered approach.

Symptoms of Congenital Lung Malformations

Children with congenital lung malformations may have these symptoms:

  • Trouble breathing
  • Frequent or repeated chest infections (pneumonia), or chest infections that don't clear up as quickly as doctors expect
  • Wheezing
  • Shortness of breath
  • Pain with breathing
  • Trouble eating and gaining weight as babies

Diagnosing Congenital Lung Malformations

  • Often, lung malformations are diagnosed because they show up on a routine prenatal ultrasound. If this happens, the team at Seattle Children’s Prenatal Diagnosis and Treatment Program can work with you to get ready for the birth and plan for any treatments your baby may need.

    If malformations are diagnosed before your baby is born, your baby’s medical team will monitor their condition. This may include frequent ultrasounds or other imaging studies, like fetal MRI (magnetic resonance imaging) and fetal echocardiogram. The team will check the size of the malformations and watch for signs of problems.

    It is possible, but not likely, that your child’s malformations may shrink before birth. All babies with these 2 types of lung malformations (CCAMs and PSs) will have imaging studies after they are born to evaluate their malformations. Usually, this means having a chest X-ray and a CT (computed tomography) scan (sometimes called a “CAT scan”).

    Some CCAMs and PSs stay the same size or get bigger before birth. If this happens, our team will provide care before birth if any is needed. They will also make a plan to manage your child’s condition after delivery.

    Before your baby’s birth, doctors may use a measurement called CVR to help tell whether your baby is at low risk or high risk for heart failure and hydrops. CVR stands for CCAM volume–to–head circumference ratio. To get the CVR, the doctor divides the size (volume) of the CCAM by the size (circumference) of your baby’s head. A CVR of 1.6 or greater means higher risk.

    If your baby has PS, doctors may use a genetic test (fetal karyotyping) before birth to check for problems with your baby’s chromosomes.

  • Some lung malformations, mainly small ones, have no effects at all. They may be found for the first time later in life when your child has an X-ray for some other reason.

    If malformations were not diagnosed before birth and your child develops symptoms of a malformation, your child’s doctor will ask for a detailed history of their illness and will do a thorough exam.

    Your child will likely need imaging studies to check for lung problems. Most likely, your child will need a chest X-ray and a CT scan of the chest. The doctor may also use other studies, including MRI (magnetic resonance imaging), bronchoscopy (threading a thin tube with a camera through the child’s mouth or nose to their airways) and echocardiogram.

Treating Congenital Lung Malformations

Congenital lung malformations may have a wide range of effects, from mild to serious. There are many treatment options. The best options for your child depend on the effects on their health.

Surgery is almost always needed to remove the malformation. This helps to correct problems your baby may have now, such as not having enough room for their lungs to develop fully. It also helps your child avoid future problems, such as getting repeated chest infections or having the malformation turn into cancer (become malignant).

For most children with lung malformations, the outlook is excellent. For babies with congenital heart failure that leads to hydrops, the situation is more serious.

  • If a malformation is causing hydrops before birth, doctors may give you medicines called corticosteroids. This treatment, which is being tested in clinical studies, helps to control or clear up hydrops in some babies.

    Doctors may recommend that you deliver your baby early so your child can have surgery and any other necessary treatments right away.

    If your baby is too young to be delivered, surgeons may be able to perform surgery on the baby before birth (fetal surgery). They may place a tube that lets extra fluid flow out of the space around the baby’s lung into the amniotic fluid in the womb (thoracoamniotic shunting). This relieves pressure on the baby’s lung, heart and blood vessels, and may clear up hydrops.

    Another option with fetal surgery may be to remove the lobe (or lobes) that have CCAMs or PSs. Fetal surgery is rarely needed and requires special expertise. Few hospitals do it. We refer patients who need fetal surgery to the University of California San Francisco Medical Center.

  • Treatment for children with congenital lung malformations (CCAMs or PSs) without hydrops will need additional monitoring and may need surgery to remove the malformations.


    If CCAMs or PSs are diagnosed before birth but are not causing hydrops or any other serious problems, then no treatment is needed until after the baby is born. Your baby’s medical team will monitor your baby’s condition for any changes. Most babies with CCAMs or PSs do not need treatment before birth.

    After delivery, your baby will need a chest X-ray to check the malformation. If your baby is doing well (such as breathing and eating well and gaining weight), your baby will be able to go home and will come back for a clinic visit in a couple of weeks.

    During the first few months after birth, every baby diagnosed with a malformation before birth will have a CT (computed tomography) scan to check the malformation again.


    If your baby continues to do well, the doctor will most likely recommend surgery to remove the malformation when your baby is between 3 months and 12 months old. There is less risk using anesthesia (medicine to make your baby sleep without pain) at this age than right after birth. This still leaves plenty of time for your baby’s healthy lung to recover and grow to nearly normal size.

    Even if your baby seems to have no problems now from the malformation, doctors recommend removing it. Malformations (both CCAMs and PSs) left in the lungs can get infected and cause pneumonia. There is also a small risk that they will become malignant. PS malformations outside the lungs (extralobular) may need to be removed even if they seem harmless now. Until these masses are taken out, it may be difficult for doctors to tell them apart from cancer, called neuroblastoma.

    If your baby cannot breathe and feed well after birth because of large malformations, the doctor may advise doing surgery soon after birth. If the problems are severe, your baby may need a breathing machine (ventilator) or extracorporeal membrane oxygenation (ECMO). ECMO is a form of life support that does the work of the lungs and heart for a baby having, or recovering from, urgent or emergency surgery.

    Most babies have malformations in only 1 section (lobe) of their lung, so they only need 1 lobe removed (lobectomy) or only part of 1 lobe. Some babies need more than 1 lobe or, rarely, an entire lung removed. With PS malformations outside the lungs, surgeons remove the malformation but no normal lung tissue.

    The surgery can be done by opening the chest (thoracotomy) or through small incisions (thoracoscopically). Your baby’s surgeon will talk with you about the risks and benefits and which option is best for your baby.

    The doctors at Seattle Children’s who give your child anesthesia are board certified in pediatric anesthesiology. This means they have extra years of training in how to give anesthesia to children.

  • After surgery, your child will be in the recovery room or the Intensive Care Unit (ICU) or Neonatal ICU (NICU), depending on their condition. Most newborns will stay in our ICU or NICU so they get the high level of care they need. Seattle Children’s was the first hospital in the United States to have a designated Level IV NICU — the highest level of care.

    When they’re ready, your child can move to a regular hospital room and eventually go home. Many older children do not need to go to the ICU after surgery. Instead, they go from the recovery room to a hospital room.

    The length of your child’s hospital stay varies. It depends partly on how your child is doing before surgery and how urgent the surgery is. If the surgery is elective (not urgent or emergent), you can expect a stay of 2 to 5 days, sometimes longer. The length also depends on your child’s condition after surgery and how quickly your child gets back to eating.

    If your child goes home quickly, the surgeon will schedule a follow-up visit 2 to 3 weeks after the surgery to make sure the incision is healing and the chest X-ray looks good. Most children are seen in clinic several months later. Some are followed in the Pulmonary Medicine Clinic, depending on their condition. The team from our Surgery Pulmonary Follow-Up Clinic will work with your child’s other healthcare providers to make sure they get the care they need.

    If your child stays in the hospital longer, the surgeon will stay closely involved in their care while in the hospital.

  • Children whose malformations are not found until later in life have the same treatment options. Doctors will advise about removing the malformation – either to clear up current problems, such as chest infections, or to prevent future risks, such as the risk of cancer.

Contact Us

Contact our Pediatric General and Thoracic Surgery Department at 206-987-2794, extension 4, for an appointment, second opinion or more information about congenital lung malformations.

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