Cystic adenomatoid malformation of the lung is a rare form of congenital pulmonary disease. It has been found in all lobes, it is rarely bilateral, and is associated to hydramnion, placental edema, and fetal hydrops. It is divided into three types, with different clinical and histologic characteristics. Intrauterine diagnosis is possible by means of ultrasound examination, and the treatment of choice is lobectomy. The authors describe four cases seen at their hospital and review the literature.

Keywords: Cystic adenomatoid malformation. Congenital malformation. Lung.