title: CD34-immunoreactive balloon cells in cortical malformations.
abstract: Balloon cells are histopathological hallmarks of various cortical malformations, i.e., focal cortical dysplasia (Taylor's type, FCD IIb), hemimegalencephaly (HME) or cortical tubers (tuberous sclerosis, TSC). Whether this intriguing cell type results from similar pathogenetic pathways remains to be shown. Here, we analyzed the immunohistochemical distribution pattern of the CD34 epitope in surgical specimens from 34 patients with FCD IIb, compared to that of 6 patients with TSC and 3 patients with HME. In normal brain, CD34 occurs only transiently during neurulation, but cannot be detected in mature neuroectodermal cell progenies. In contrast, 58% of our patients showed CD34 immunoreactivity within a subpopulation of balloon cells. Interestingly, CD34-positive balloon cells were confined to the white matter, but never observed in neocortical layers. Furthermore, balloon cells expressing neurofilament protein were also restricted to white matter, whereas GFAP-positive balloon cells were observed either in white or gray matter location. Clinical characteristics did not significantly differ between patients with CD34-positive versus CD34-negative lesions. No significant correlation was found between CD34 expression and genetic alterations of the TSC1 gene, which is affected in many FCD and TSC patients and which plays a role in the regulation of cell size. Further studies are warranted to clarify the restricted expression of CD34 in balloon cells of the white matter.
authors.affiliation: Epilepsy Center, University of Freiburg, Breisacher Str. 64, 79106 Freiburg im Breisgau, Germany. Fauser@nz11.ukl.uni-freiburg.de
authors.forename: Susanne
authors.initials: S
authors.lastname: Fauser
authors.forename: Albert
authors.initials: A
authors.lastname: Becker
authors.forename: Andreas
authors.initials: A
authors.lastname: Schulze-Bonhage
authors.forename: Michelle
authors.initials: M
authors.lastname: Hildebrandt
authors.forename: Ingrid
authors.initials: I
authors.lastname: Tuxhorn
authors.forename: Heinz W
authors.initials: HW
authors.lastname: Pannek
authors.forename: Rainer
authors.initials: R
authors.lastname: Lahl
authors.forename: Johannes
authors.initials: J
authors.lastname: Schramm
authors.forename: Ingmar
authors.initials: I
authors.lastname: Blümcke
mesh_terms: D000293:Adolescent; D018952:Antigens, CD34 / Q000378:metabolism*; D001927:Brain Diseases / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D002540:Cerebral Cortex / Q000002:abnormalities* / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D005838:Genotype; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D007231:Infant, Newborn; D019656:Loss of Heterozygosity; D010641:Phenotype; D012640:Seizures / Q000209:etiology; D014402:Tuberous Sclerosis / Q000235:genetics / Q000378:metabolism / Q000473:pathology
chemical_list: D018952:Antigens, CD34