Antenatal diagnosis of extralobar pulmonar sequestration.

Extralobar pulmonary sequestrations (ELS) are masses of non-functioning lung tissue that are supplied by an anomalous systemic artery and do not have a bronchial connection to the native tracheobronchial tree. On prenatal ultrasonography, an ELS appears as a well-defined echodense, homogeneous mass. Detection by color flow Doppler ultrasonography of a systemic artery from the aorta to the fetal lung lesion is a pathognomonic feature of fetal ELS. MR imaging may help in the diagnosis of pulmonary sequestration by demonstrating a solid, well-defined mass, and the feeding artery. In this case report, we describe the sonographic and MR diagnosis of an ELS in a fetus at 22 weeks gestation with a review of the available literature.