Fetal case of congenital cystic adenomatoid malformation of the lung: fetal therapy and a review of the published reports in Japan

In utero resolution of microcystic congenital cystic adenomatoid malformation after prenatal betamethasone therapy: A report of three cases and a literature review

Fetal congenital cystic adenomatoid malformation (CCAM) can progress to nonimmune hydrops, and the mortality rate of CCAM with hydrops is reported to be nearly 100%. We describe three microcystic CCAM cases in which the fetal condition improved after maternal betamethasone therapy. The median gestational age at steroid administration was 23 5/7 weeks' gestation. The CCAM decreased in size in all cases. Our series showed a 100% hydrops resolution rate (2/2) and a 100% survival rate (3/3). Our experience suggests the efficacy of betamethasone treatment on fetuses with microcystic CCAM who have fluid collection or are at risk of developing hydrops.

Neonatal outcome after prenatal interventions for congenital lung lesions

Congenital lung lesions, mostly congenital cystic adenomatoid malformations (CCAMs) and bronchopulmonary sequestrations (BPSs), are uncommon disorders. Prenatal intervention in severely affected (hydropic) fetuses has drastically improved perinatal survival. Not much is known, however, on the short-term and long-term respiratory and neurodevelopmental outcome. Several small case series have been reported and suggest an increased incidence of neonatal morbidity, mainly associated with prematurity and respiratory failure at birth. Overall, neonatal mortality and morbidity after prenatal interventions for CCAM seems to be worse than for BPS. This review focuses on the neonatal outcome after prenatal intervention for congenital lung lesions and summarizes the results reported in the literature.

Prenatal interventions for fetal lung lesions

The widespread availability of high resolution ultrasound equipment and almost universal routine anatomy scanning in all pregnant women in the developed world has lead to increased detection of abnormalities in the fetal thorax. Already in the 1980s, large pleural effusions and significant macrocystic lesions in the fetus were easily detected on ultrasound. However, smaller lung tumours were often missed. Nowadays, fetal medicine centres receive many referrals for evaluation of fetal lung lesions, of which the most common are congenital cystic adenomatoid malformation and bronchopulmonary sequestration. Almost invariably, both the parents and the referring physicians experience anxiety after detection of large lung masses in the fetus. However, the vast majority of the currently detected fetal lung lesions have an excellent prognosis without the need for prenatal intervention. In the small group of fetuses in which the prognosis is poor, almost exclusively those with concomitant fetal hydrops and cardiac failure, several options for fetal therapy exist, often with a more than 50% survival rate. Indications, techniques, complications and outcomes of these interventions will be described in this review.

Prenatal diagnosis and outcome of echogenic fetal lung lesions

OBJECTIVE

To describe the antenatal findings and outcome of fetuses with echogenic lung lesions.

METHODS

This was a retrospective study of the prenatal sonographic features, antenatal management and outcome of 193 fetuses with an echogenic lung lesion diagnosed at 18-35 weeks of gestation. There were nine cases of congenital high airway obstruction syndrome (CHAOS), 170 cases of cystic adenomatoid malformation (CAM) and 14 cases of pulmonary sequestration (PS). A literature search was also carried out to compare our data with those of previous series.

RESULTS

The prognosis in our series of fetuses with CHAOS was invariably poor, but the literature describes a handful of survivors after delivery by Cesarean section and ex-utero intrapartum therapy (EXIT). Of the cases in our series with PS and no pleural effusions, more than 95% survived; in half of these cases the lesion resolved antenatally and in the other half sequestrectomy was carried out postnatally. In cases with PS and pleural effusions, successful treatment was provided by the placement of thoracoamniotic shunts or occlusion of the feeding blood vessel by ultrasound-guided laser coagulation or injection of sclerosants. In cases with CAM and no hydrops, there was more than 95% survival and in up to half of the cases there was sonographic evidence of spontaneous antenatal resolution of the hyperechogenic lesion, which was confirmed by postnatal imaging in about 60% of the cases. Of the cases with CAM with hydrops managed expectantly, more than 95% died before or after birth. Of the cases with macrocystic CAM with hydrops, two-thirds survived after placement of a thoracoamniotic shunt. In cases with microcystic CAM with hydrops, there is some evidence that open fetal surgery with lobectomy could improve survival but such treatment is highly invasive for the mother.

CONCLUSIONS

CHAOS is a severe abnormality, whereas CAM and PS are associated with a good prognosis. In a high proportion of fetuses with hyperechogenic lung lesion, there is spontaneous antenatal resolution and the underlying pathology may be transient bronchial obstruction.