The fetal thorax: noncardiac chest anomalies

Fetal thoracic anomalies often lead to pulmonary hypoplasia with subsequent fetal or neonatal demise. Therefore, in utero sonographic identification of these anomalies is important. Unlike cardiac anomalies, most noncardiac thoracic abnormalities are easily detected with ultrasound. An unusually small thorax is usually obvious to the experienced sonographer, and thoracic masses are commonly observed on the routinely obtained four-chamber view of the heart. This article reviews the many causes of pulmonary hypoplasia with an emphasis placed on thoracic masses. Many examples of pathological fetal thoracic conditions are provided as well as a listing of differential considerations with regard to sonographic appearances of chest masses.