Prospective study of antenatally diagnosed congenital cystic adenomatoid malformations.

PURPOSE: Congenital cystic adenomatoid malformations (CCAMs) are increasingly diagnosed in recent years due to the routine usage of antenatal ultrasound. The aim of this study was to present the natural course and outcome of antenatally diagnosed cystic lung diseases, which were prospectively studied. METHODS: Between the period June 2004 and June 2010, 25 fetuses with suspected CCAMs were seen in a single tertiary maternal fetal unit. One child was excluded as the fetal MRI suggested congenital diaphragmatic hernia. Data were prospectively entered into a database including antenatal and postnatal findings which were then analyzed. RESULTS: Mean gestational age at the time of diagnosis was 20.8 weeks (range 17-29). Fetal interventions included amnioreduction (n = 2) and fetal thoracocentesis (n = 3) in one child. The mean gestational age at delivery was 38.5 weeks (range 31.6-40.6). None of the mothers underwent termination of pregnancy or spontaneous abortion. All patients underwent postnatal radiological assessment. Of the 24 cases, 5 children were symptomatic in the immediate neonatal period and 19 were asymptomatic. Anatomical surgical resection was undertaken in all symptomatic cases. There was one death in this group due to severe pre-existing pulmonary hypoplasia. Among the 19 asymptomatic cases, 5 children were managed conservatively as the lesions were not significant and the remaining 14 (73%) underwent surgical resection. The mean age at surgery was 11.1 months (range 3.3-34 months). Postnatal pathology confirmed CCAM in all operated cases, except one who had pulmonary sequestration. CONCLUSION: Antenatally diagnosed CCAMs have an excellent prognosis except in children with a large lesion and associated with lung hypoplasia. Postnatal investigations are required in all cases to confirm the diagnosis. Symptomatic CCAMs require immediate surgery in the neonatal period with a good outcome. Asymptomatic CCAMs can be safely operated between 9 and 12 months of age.