Fetal opercular cavernous angioma causing cerebral cleft: contralateral primitive vascular anomaly and subicular dysgenesis.

We describe a 22-week female fetus after pregnancy was terminated because of fetal magnetic resonance imaging showing a large left cerebral hemispheric cleft suggestive of porencephaly or schizencephaly. Postmortem examination revealed a large cavernous angioma of the left opercular region with evidence of previous hemorrhage and extensive cerebral infarction. In the right hemisphere, another vascular malformation within the frontal germinal matrix consisted of an aggregate of primitive vessels not yet canalized. Selective dysgenesis of the right subiculum also was demonstrated. This case illustrates not only a severe encephaloclastic effect of cavernous angioma in fetal brain but also the importance of fetal autopsy to help correlate and explain fetal neuroimaging. Potential future prenatal treatment of fetal angiomata requires precise in utero diagnosis.