Denver General Hospital, 777 Bannock Street, Denver, CO 80204, U.S.A.
University of Colorado School of Medicine, Denver, Colorado, U.S.A.
Abstract:
Exencephaly as a precursor of anencephaly is well delineated in animal studies. In humans, a similar though unproven embryologic sequence is postulated. In the case reported, serial ultrasound studies allowed us to identify a 16-week human exencephalic fetus and observe the cephalic changes during its progression to a classic anencephalic appearance.