OBJECTIVE: Our purpose was to review our experience with fetal congenital cystic adenomatoid malformation and extralobar pulmonary sequestration emphasizing natural history, management, and outcome. STUDY DESIGN: We conducted a retrospective review of 175 fetal lung lesions diagnosed by antenatal ultrasonography at 2 fetal treatment centers. RESULTS: There were 134 congenital cystic adenomatoid malformationcases. Fourteen women underwent elective abortion, 101 women were managed expectantly 13 women had fetal surgery, and 6 women had placement of a thoracoamniotic shunt. For the congenital cystic adenomatoid malformation lesions that were not associated with nonimmune hydrops, all babies survived. Of 25 large congenital cystic adenomatoid malformations that had associated hydrops that were followed expectantly, all fetuses died before or shortly after birth. Fetal surgical resection of the tumor (fetal lobectomy) was performed at 21 to 29 weeks' gestation in 13 hydropic fetuses with 8 fetuses continuing gestation with subsequent hydrops resolution, impressive in utero lung growth, and neonatal survival. Six fetuses with a very large solitary cyst underwent thoracoamniotic shunting and 5 survived. There were 41 extralobar pulmonary sequestration cases. Twenty-eight extralobar pulmonary sequestrations dramatically regressed on serial prenatal sonography, were asymptomatic after birth, and were only detectable by imaging studies postnatally (no resection required). Of the remaining 13 extralobar pulmonary sequestration cases, 2 underwent elective abortion, 7 symptomatic lesions were resected after birth with survival, 1 hydropic fetus died, and 3 fetuses had an associated tension hydrothorax with secondary hydrops that was successfully treated by either fetal thoracenteses or thoracoamniotic shunting followed by postnatal resection. CONCLUSIONS: The natural history of prenatally diagnosed lung masses is variable, and associated anomalies are rare. Most congenital cystic adenomatoid malformation lesions can be managed with maternal transport, planned term delivery, and postnatal resection. Many extralobar pulmonary sequestrations dramatically decrease in size before birth and may not need treatment after birth. Fetal therapy is now an option for lung lesions associated with nonimmune hydrops.
