Early prenatal diagnosis of type III bilateral congenital cystic adenomatoid malformation of the lung.

We present a case of type III fetal cystic adenomatoid malformation with bilateral total involvement of the lungs. The characteristic sonographic findings are echogenic homogeneous lung mass, fetal ascites and placentomegaly. The early diagnosis at 16 weeks' gestation allows the elective termination of pregnancy because of the likely fatal prognosis. To our knowledge, this is the earliest reported case of congenital cystic adenomatoid malformation of the lung that has been detected prenatally.