A newly described thoracic vascular malformation in fetuses with Down syndrome

To report the association between thoracic vascular malformations observed in the first trimester of pregnancy and Down syndrome.

The clinical features were reviewed of seven fetuses undergoing chorionic villus sampling (CVS) for increased nuchal translucency (NT) thickness, in which color Doppler ultrasonography revealed a vascular malformation in the fetal thorax.

The crown-rump length of the fetuses ranged from 58 to 78 mm and NT measurements ranged from 2.9 to 10.0 mm. Color Doppler allowed the identification of a highly vascular structure in the posterolateral portion of the fetal thorax, in proximity to the costovertebral angle, at the level of a four-chamber view of the heart. The lesions had a globular shape and were 4-6 mm in diameter, occupying almost one third of the hemithorax. Down syndrome was diagnosed in five out of the seven cases. In the only affected case that underwent postmortem examination, a hemangioma of the chest wall was demonstrated. In the two fetuses with normal karyotype, the lesion disappeared by mid-gestation.

We report an association between the prenatal Doppler finding of a vascular tumor in the fetal chest and Down syndrome.