Trilobar holoprosencephaly ("triprosencephaly"): a unique type of cerebral malformation.

Little is known about the neuropathology of the median facial cleft syndrome, which presents as a combination of a wide range of teratological manifestations. We report a unique type of cerebral malformation combined with the median facial cleft syndrome in a 7-day-old female infant with malformations of toes and fingers, hypertelorism and a median cleft nose, as well as a frontally protruding, dorsomedian hornlike cele. At autopsy, the cranium presented facial clefts and bony defects, resulting in partitioning of the anterior cranial fossa into three compartments. The brain had malformative features of lobar holoprosencephaly combined with tripartition of frontal lobes, including an encephalomeningocystocele originating from a right accessory frontal lobe.