Photomicrographs demonstrate the histopathology of the heterotopia in patient 7. A, A cluster of disorganized neurons (black arrows) is juxtaposed to an adjacent normal-layered foliar cortex (bracketed by black arrowheads) (hematoxylin-eosin stain, original magnification ×4). B, Heterotopia comprises a dominant population of morphologically normal granular cell neurons in a background of mixed glial cells (hematoxylin-eosin stain, original magnification ×20). C, Purkinje cells (darkly staining cells) are scattered within the granular cell neurons as well as within the adjacent cortex (HuC stain, original magnification ×4). D, Nerve fibers (darkly staining material) surround and traverse the cluster of heterotopic neurons (calretinin stain, original magnification ×4).