Congenital cystic adenomatoid malformation in the fetus: a hypothesis of its development.

We present a case of congenital cystic adenomatoid malformation of the lung diagnosed at 34 weeks of gestation in the setting of polyhydramnios. The fetus had CCAM in the L lung, with mediastinal shift to the right and ascites. The neonate underwent drainage of cysts and subsequent left lung lobar resection with improvement in respiratory function. The pathology of CCAM is reviewed in detail. We speculate the role of alcohol as a teratogen through retinoic acid at 8-10 weeks of gestation when fetal lungs are actively developing.