Non-mosaic trisomy 20 presenting at 21 weeks' gestation as a thoraco-abdominal mass.

Non-mosaic trisomy 20 is rare in fetuses surviving beyond the first trimester. We report a case of a fetus with non-mosaic trisomy 20 in amniotic fluid cultures obtained during the prenatal evaluation of an unusual thoraco-abdominal mass which was found at autopsy to be pulmonary sequestration. Gross inspection and autopsy of the fetus revealed multiple anomalies. Copyright 2001 John Wiley & Sons, Ltd.