ABSTRACT
The majority of fetal chest tumors are benign and tend to be identified in the second trimester. In the absence of fetal hydrops, they have a favorable prognosis. They are identified as echogenic lesions or mixed lesions with anechoic lesions interspersed within the echogenic areas. A predominantly echogenic lesion should be approached with the differential diagnoses of congenital cystic adenomatoid malformation (CCAM), pulmonary sequestration, or temporary bronchial obstruction. The presence of systemic arterial supply from the thoracic or abdominal dorsal aorta would suggest the diagnosis of sequestration. Most of the lesions are found to have both CCAM and sequestration on histopathological examination. It is recommended to monitor the pregnancies serially in order to exclude the development of fetal hydrops. The majority of bronchial obstruction and CCAM, however, regress spontaneously so much so that as the pregnancy advances, the lesions are difficult to identify on scan.
