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.