What is congenital cystic adenomatoid malformation of the lung?

Congenital cystic adenomatoid malformation of the lung (CCAM/CPAM) happens when one or more non-cancerous masses of lung tissue (cysts) develop and overtake part of your baby’s lung.

Based on the size and number of cysts, there are three types of classification for this anomaly. An ultrasound will be able to give your doctor more information about what’s happening.

• Type I This is a single cyst or a small number of large cysts. The size of cysts range between 3 and 10 centimeters. This happens in about 50 percent of the cases.
• Type II This is a collection of many cysts. Type II makes up 40 percent of cases.
• Type III There are several tiny cysts, but they are very solid. It looks like a solid mass. This happens in about 10 percent of cases.

These cysts are usually on only one lung (85 percent to 95 percent), but occasionally they occur on both lungs (two percent).

Sometimes the cysts shrink and disappear on their own. Other times the mass may grow to be life threatening to the fetus.

How is the condition diagnosed?

This condition is diagnosed by an ultrasound during pregnancy. A color flow Doppler ultrasound showing the blood supply to the cyst helps to confirm the diagnosis.

How is congenital cystic adenomatoid malformation of the lung treated?

The diagnosis of Congenital Cystic Adenomatoid Malformation (CCAM) may have serious implications for the health of the mother. If the fetus develops hydrops, or massive fluid retention, the mother may “mirror” the sick fetus, becoming ill with signs of preeclampsia or toxemia. Mothers must be carefully monitored for signs and symptoms of the maternal mirror syndrome. The only option may be early delivery. The fetus will need to be closely followed by serial ultrasounds for signs of hydrops, and to assess the remaining normal lung. Often times a fetal MRI will be recommended to better assess the condition.

Fetal surgery to drain the cysts might be an option if hydrops has already developed in the baby. Your doctor will only suggest this surgery if you’re healthy.

If the baby does not develop hydrops, we will create a specialized plan for your delivery. Special arrangements might need to made, depending on the size of the cysts. For example, if a CCAM lesion shrinks in size, which occurs in approximately 10 to 20 percent of cases, delivery at a local hospital is certainly possible. Delivery does not need to be early, nor does it have to be by cesarean.

Our nurse navigator may arrange for you to meet with our neonatologists and pediatric surgeons while you are still pregnant to develop the best plan for removing the cysts after your baby is born. You will also be given the opportunity to tour our neonatal intensive care unit (NICU) if your baby is expected to receive care there. Larger cysts might be removed immediately after the baby is born. For smaller cysts, follow-up surgery a few weeks after birth might be recommended. All the cysts should be removed to help prevent the risk of lung infection.

How will congenital cystic adenomatoid malformation of the lung affect my baby during and after surgery?

Your baby will be cared for in our neonatal intensive care unit (NICU) after birth and after surgery. The prognosis for babies after lung surgery depends on the size and location of the cysts. To help determine the size and location of the cysts, special imaging such as CT or MRI may be performed. Once this is determined, an individualized plan of care will be developed. Most babies who undergo surgery to remove the cysts do well afterward. Since a child’s lungs continue to grow until the age of 9, there is usually time for the lungs to grow and develop after surgery.