Cobblestone lissencephaly in Schinzel-Giedion syndrome.

The brain of a 5-year-old boy with Schinzel-Giedion syndrome displayed a cobblestone appearance of orbital and lateral aspects of frontal lobes due to widespread glioneuronal meningeal heterotopia. Meningeal heterotopia consisted of scattered neurons, neurofilament positive axons, and myelinated fibers accompanied by striking astrocytic gliosis. The underlying cortex showed gaps in the pial basal lamina, distorted neuronal layering, and focal polymicrogyria. The number of capillaries appeared increased throughout the brain. Mild hydrocephalus was associated with a slight atrophy of corpus callosum as well as villous hyperplasia and marked stromal degeneration of the choroid plexus. Our findings suggest that Schinzel-Giedion syndrome may represent One more entity within enlarging spectrum of lissencephalic cortical dysplasia syndromes.