Prenatal diagnosis of congenital cystic adenomatoid lung malformation: case report and review of the literature.

Congenital cystic adenomatoid malformation of the fetal lung is an extremely rare developmental abnormality characterized by excessive overgrowth of the terminal respiratory bronchioles at the expense of the saccular spaces. We present a case of a 33-year-old, gravida 2, para 1, woman with congenital cystic adenomatoid lung malformation-type II diagnosed by ultrasound at the 20th week of gestation. On the right side of the chest an area with a maximum diameter of 18.5 mm and with small cystic lesions was recognized. The maximum diameter of the cysts was 0.5 cm. There were no other fetal abnormalities. The pregnancy was terminated and the postmortem examination confirmed the ultrasonographic findings. The cysts had the appearance of bronchiolus-like structures and were lined with cuboidal and columar epithelium. Distended alveoli were present, while the airways were normal in structure. No other congenital anomalies were found. In conclusion, in this study we describe the ultrasonographic and pathologic findings of an unusual case of congenital cystic adenomatoid malformation of the fetal lung.