Abnormal lung tissue, in the form of multiple bubbles (cysts), is frequently found prior to birth by routine prenatal ultrasound. These are called congenital lung cysts. They are also known as congenital cystic adenomatoid malformations (CCAM) or congenital pulmonary airway malformations (CPAM).
Very large cysts can be cause symptomatics and require drainage before birth or emergency removal immediately after delivery. However, most are asymptomatic and require no surgery in the neonatal period. Occasionally, after several months of observation, a cyst may completely disappear.
Typically, cystic malformations that persist may become infected, increase in size, or increase the likelihood of lung tumors development later in life. For these reasons, cystic malformations that don’t go away require surgery for removal.