Ventricular diverticula with localized dysgenesis of the temporal lobe in cloverleaf skull anomaly.

An early fetal case of cloverleaf skull anomaly associated with thanatophoric chondrodystrophy is described. Localized ventricular diverticula are a peculiar finding. In addition there are previously described malformations limited to the temporal lobes and comprising plump gyri with abnormal deep sulci, thick periventricular heterotopias, dysgenesis of the parahippocampal gyrus, agenesis of the Ammon's horn, and small micropolygyria. The skull deformity is not dependent on hydrocephalus, demonstrating inconsistencies in previous pathogenetic concepts.