Outcome of 25 pregnancies complicated with CCAM

Abstract

Congenital cystic adenomatoid malformation (CCAM) is a pulmonary developmental anomaly arising from an overgrowth of the terminal respiratory bronchioles, while the development of the alveoli is completely suppressed except at the periphery. The condition, in the vast majority of cases is confined to a single lung (85%) or lobe. Congenital cystic adenomatoid malformation has been classified into three subgroups according to the size of the cysts. The inheritance pattern of the lesion appears to be sporadic, with no known teratogenic associations. The condition is usually isolated and there is no association with chromosomal defects. The ultrasound diagnosis is based on the finding of a solid or cystic, non‐pulsatile intrathoracic tumor. Common associated findings are polyhydramnios (65%), which is likely to be due to decreased fetal swallowing, the consequence of esophageal compression by the mass or decreased absorption of lung fluid by the hypoplastic, malformed lungs, hydrops (common in microcystic form) and placentomegaly (in cases of hydrops). Unilateral lesions are often associated with deviation of the mediastinum in the contralateral side. In bilateral disease, the heart may be severely compressed, and this is usually associated with ascites from venocaval obstruction or cardiac compression. We wish to present the outcome of 25 pregnancies where a diagnosis of congenital cystic adenomatoid malformation was made on the basis of ultrasound findings during second and third trimester scans. The patients were subsequently managed through the Fetal Management Unit at the Royal Women's Hospital over the 6‐year period from 1995 to 2001. We will present data on the progression of the lesions through pregnancy, pregnancy outcome with short‐ and long‐term follow up data on the babies.