Fetal cephaloceles: diagnosis with US.

The prenatal sonograms of 15 fetuses with cephaloceles (13 occipital, one ethmoidal, and one frontoparietal) were retrospectively reviewed. The prognosis for fetuses with cephaloceles was poor: Only three of 14 with follow-up were born alive (21%), and all are likely to be handicapped. Karyotypes were abnormal in four of nine fetuses tested (44%). Associated cranial abnormalities observed in various numbers of fetuses included ventriculomegaly, the "lemon" sign, a flat basioccipital, "beaked" tectum, and bone defect. A wide variety of neural and nonneural anomalies were associated with cephaloceles. At least one sonographically observed concomitant neural or nonneural axis abnormality or an abnormal karyotype was present in nine of 15 fetuses (60%). Some associated neural malformations noted pathologically were not observed prenatally. Cranial meningoceles were not accurately distinguished from encephaloceles sonographically, and they also were associated with a poor prognosis. Comparison of findings in fetuses with cephaloceles with those of 15 fetuses with cystic hygromas revealed that the two abnormalities can usually be distinguished by the relationship of the mass with the neck and by other cranial findings present in fetuses with cephaloceles but absent in association with cystic hygromas.