What is Congenital Cystic Adenomatoid Malformation?

Congenital cystic adenomatoid malformation is an uncommon type of fetal lung defect. During the late stages of lung development, one or more abnormal pieces of cystic tissue begin to grow in place of a normal lung lobe. Small cysts may not cause any major health problems, but large malformations can cause respiratory distress or heart failure shortly after birth. Thanks to modern technology and standard prenatal care procedures in developed countries, most cases of congenital cystic adenomatoid malformation are discovered before infants are even born. Postnatal surgery is often necessary to drain cysts and repair lung tissue.

The causes of congenital cystic adenomatoid malformation are not entirely known. Some research studies have identified a genetic link to the problem, though malformations occur so rarely that an inheritance pattern has not been found. There does not appear to be a correlation with the mother's age, health, or diet.

In most cases, cystic lesions begin to develop in the second or third trimester. They are usually limited to a single lobe on one lung, though they can appear in both in very rare cases. Large lesions can cause the lungs or heart to be displaced in the chest cavity, which may cause serious complications. A cyst that ruptures or causes nearby healthy tissue to tear may result in fluid buildup in the lungs and resulting respiratory failure.

An infant who is born with a small congenital cystic adenomatoid malformation may have breathing difficulties and a slow heart rate. Coughing, chest pain, fever, and refusal to feed are common. If the condition goes untreated, a baby is at an increased risk of frequent respiratory tract infections and chronic breathing troubles.

A doctor or nurse can detect congenital cystic adenomatoid malformation during a routine sonogram. Ultrasound images that reveal dense patches of lung tissue, overgrown lungs, or a misplaced heart are all signs of a possible malformation. When an abnormality is discovered, a team of radiologists and obstetricians can study the problem and determine the best course of treatment. Inducing premature labor or trying to operate on the fetus while it is still in the womb are only necessary if the malformation is obviously life-threatening.

In less serious cases, doctors can simply monitor fetal development and wait for the mother to go into labor naturally. As soon as the baby is born, he or she is evaluated and given oxygen therapy if necessary. X-rays can confirm the presence of cysts and help doctors determine the urgency of surgery. A very delicate procedure is performed to drain fluid from the cyst and chest cavity. Remaining healthy tissue is mended as best as possible to preserve lung functioning. In some cases, an entire lung needs to be removed. With follow-up care and frequent monitoring through infancy and childhood, most patients with congenital cystic adenomatoid malformation are able to recover without lasting complications.