Congenital Cystic Adenomatoid Malformation

What is a congenital cystic adenomatoid malformation (CCAM/CPAM)?

Congenital cystic adenomatoid malformation (CCAM) is a benign lung lesion that appears before birth as a cyst or mass in the chest. It is made up of abnormal lung tissue that does not function properly, but continues to grow. CCAM is also frequently referred to as a congenital pulmonary airway malformation (CPAM).

CCAM/CPAM is the most common type of fetal lung lesion. It develops before a baby is born, and can vary in size and be either fluid-filled or solid. A large cyst is called a macrocystic lesion, and a small cyst or solid appearing lesion is called microcystic.

Some CCAM/CPAMs can be life-threatening if they are not treated, so early and accurate diagnosis is important. The vast majority of CCAM/CPAM lesions are small enough that they will not cause any problems to the baby during pregnancy and the CCAM/CPAM can be removed after birth. However, some large lesions can cause serious and even fatal complications, including fetal heart failure (also called fetal hydrops) or maternal mirror syndrome. These cases may require treatment before birth.