저자들은 임신 37주에 산전 초음파를 통하여 횡격막하 고반향성 종괴를 발견한 후 초음파상의 특징에 따라 폐격리증을 진단하고 생후 수술 및 병리조직학적 소견에 따라 확진된 외엽성 폐격리증 1예를 체험하였기에 문헌고찰과 함께 보고하는 바이다.

Pulmonary sequestration is a congenital anomaly of lung in which a portion of lung par-enchyma has no communication with the tracheobronchial tree and receives its blood supply via systemic artery. Sequestration represents a developmental anomaly of tracheobronchial branching with pe- rsistence and localized development of a separated branch fragment and retention of its embr- yonic systemic vascular supply. In the review of the literature, this disease is so rare that only 540 cases were reported worldwide. The anomaly is divided into 2 types；intralobar and extr- alobar. The ratio of intralobar type and extralobar type is about 3.5 : 1 and intralobar type is more common than the latter in all age groups. The intralobar type is contiguous with normal lung parenchyma and within the same visceral pleural envelope ; in contrast, the extralobar type is enclosed within its own pleural membrane, usually close to a normal lung but separated and discovered most commonly in the left hemithorax with rare cases in the abdominal cavity. Traditionally, this disease has been presented as an incidental lung mass in routine chest X-ray in the postnatal period and with confirmation by aortic angiography, but recently, pul- monary sequestration is diagnosed in the antenatal period along with the development of ant- enatal ultrasonography. Ultrasonography shows the pulmonary sequestration as a hyperecho- genic mass near the diaphragm with posterior echo-free shadow. We have experienced one case of pulmonary sequestration which was found by antenatal ultrasonography and confirmed by operation and histopathologic report in the neonatal period, and we present the case with a brief review of the literatures.