Mosaic Amplification of Multiple Receptor Tyrosine Kinase Genes in Glioblastoma

Here we present a novel example of genetic heterogeneity in human malignant brain tumors, in which multiple closely-related driver genes are amplified and activated simultaneously in adjacent intermingled cells. We have observed up to 3 different receptor tyrosine kinases (EGFR, MET, PDGFRA) amplified in single tumors in different cells in a mutually exclusive fashion. However, these subpopulations cannot be always observed with a genome wide studies such as aCGH. Here we include aCGH on three such mosaic cases. Analyses were performed on 350 archival specimens of glioblastoma, WHO Grade IV, seen at the Department of Pathology, Massachusetts General Hospital from 2009 to 2011. CGH on three such mosaic cases.