Lung Mass (CPAM, CCAM, & BPS)
In rare circumstances, fetuses can develop lung masses before birth. Two of the most common of these rare conditions are congenital pulmonary airway malformation (CPAM) and bronchopulmonary sequestration (BPS).
Congenital pulmonary airway malformation (CPAM) is a mass of abnormal fetal lung tissue that forms in pregnancy. The mass displaces (pushes) on the remaining lung tissue and heart. This condition was previously known as congenital cystic adenomatoid malformation (CCAM). BPS is a very similar condition, with a mass within the chest; however, it has a large vessel feeding it from the aorta. The management is very similar.
CPAM is extremely rare, affecting only 1:25000 pregnancies. BPS is even rarer than this. Neither is considered a genetic or hereditary condition, and both are unlikely to recur in a subsequent pregnancy.
Prenatal Diagnosis
If you are referred for a suspected CPAM/BPS, our team will perform a detailed Level II ultrasound to evaluate the findings, look at the size of the mass, and calculate a CVR (CPAM volume ratio). A CVR of less than 1.6 has a good prognosis, while a CVR of greater than 1.6 indicates an increased risk of hydrops (heart failure with fluid overload in the baby, including fluid in the lungs, around the heart, in the abdomen, or in the skin). Based on these findings, we can help determine the follow-up needed and the likelihood of complications after birth.
You will also have a fetal echocardiogram with our Pediatric Cardiology team. This can be a very difficult evaluation as the heart is often pushed to the side (malpositioned) by the pressure from the mass.
Prognosis
This highly complex disease can range widely in severity and outcomes. Most fetuses will require close monitoring but will not develop complications. Additionally, most CPAMs and BPSs begin to decrease in size by 26 - 28 weeks. However, when the lungs are compressed, there is a risk of limited growth resulting in pulmonary hypoplasia (underdeveloped lungs). When the heart is compressed, it can have trouble pumping, resulting in risk for fluid overload in the fetus (hydrops).
Therapies
Most babies with CPAM will be followed closely by ultrasound, but will not require therapy during pregnancy. For some cases, prenatal steroids may be used to help decrease the size of the CPAM. For CPAM where large cysts are present, UR Medicine's Maternal-Fetal Medicine team may discuss drainage or shunt placement to remove the fluid. As the only center in Western NY offering these services, we have the experience to guide you through this.
The Expertise to Know When to Refer
When hydrops occur (in less than 10% of cases), it has a poor prognosis. Hydrops occurs for a variety of reasons, but for babies with lung masses this can result from pressure on the heart from the mass leading to heart failure and fluid overload in the baby. In these cases, fetal surgery may be an option. For women with this complication, our team has the expertise to counsel you on options and risks, quickly help to coordinate your care at one of the few centers in the country that can perform this surgery, and then see you back for close follow-up and eventual delivery at UR Medicine's Golisano Children's Hospital.
If the pregnant person develops complications from the fetal hydrops (called “mirror” syndrome), this can be extremely dangerous for both parent and baby. Early delivery and specialized maternal care may be needed, all of which are available from our team.
Following Closely, Preparing for birth
As your pregnancy progresses, you will need a variety of follow-up and care. Our fetal care coordinator will help arrange all of this with you.
Later in pregnancy, you will have a fetal MRI to look at lung volumes later in pregnancy. You will meet with the Perinatal Supportive Care team to help prepare for birth. Our teams will also meet and review plans for delivery to be ready for your child’s care needs.
Newborn Care and Delivery
Babies with CPAM are at high risk for complications during and after delivery, including pulmonary hypoplasia (underdeveloped lungs) and high blood pressure. The mass will need to be evaluated and removed. In some cases when the lesions are large, emergent care and breathing assistance including extracorporeal membrane oxygenation (ECMO) is needed.
Extracorporeal Membrane Oxygenation (ECMO)
Children born with this condition require surgery, and some will require ECMO for oxygenation while their lungs recover. We are the only center in the Finger Lakes region that offers neonatal ECMO services, and UR Medicine's Golisano Children's Hospital has a dedicated ECMO team for these critically ill infants.
Ex-Utero Intrapartum Treatment (EXIT)
In some cases, the lesions are very large and interfere with normal breathing, so surgery must take place immediately after birth. Our team may recommend a special birth plan which includes EXIT. This involves delivering the baby by Cesarean-section and immediately placing a breathing tube while the baby is still connected to the placenta. UR Medicine Maternal-Fetal Medicine has offered this type of EXIT as a management strategy for babies with severe CPAM.
Our Experience
Our experienced maternal and fetal care specialists and Golisano Children's Hospital offer a complete range of diagnostic and treatment options to care for babies with this condition. Our Maternal-Fetal Medicine team has evaluated more than 50 babies with CPAM/BPS in the last five years.
Golisano Children's Hospital's Pediatric Surgery team has decades of experience operating on infants and children, and performs approximately 2,000 operative procedures a year with excellent survival rates and outcomes.