Türk Nöroşirürji Dergisi 2017 , Vol 27 , Num 2
Molecular Classification of Primitive Neuroectodermal Tumors of the Central Nervous System (CNS-PNET)
Umut H. TOPRAK1,Dominik STURM2,Matthias SCHLESNER1,Roland EILS1, Stefan M. PFISTER2,Marcel KOOL2
1German Cancer Research Center (DKFZ), Division of Theoretical Bioinformatics, Heidelberg, Almanya
2German Cancer Research Center (DKFZ), Division of Pediatric Neurooncology, Heidelberg, Almanya
CNS-PNET is a rare, immature pediatric brain tumor with an aggressive course. Histopathology has significant limitations in reflecting the tumor biology. Therefore an international collaboration was organized and significant progress was made on undertanding the biology of this rare tumor. This work will summarize the recent findings.

323 CNS-PNET samples were analyzed for their methylation profiles to define their tumor group. The resulting tumor groups were later analyzed for differences in other molecular changes. The methylation profile indicated that 61% of all cases with a histopathological diagnosis of CNS-PNET were in fact other tumors. 24% exhibited specific molecular findings which classified them into four different variants (CNS NB-FOXR2, CNS EFT-CIC, CNS HGNET-MN1 and CNS HGNET-BCOR). A further 15% did not have any characteristics to define the tumor biology. CNS-PNET, which is classified among pediatric embryonal tumors, is genetically and pathologically a heterogenous group. Recent studies have provided significant progress in understanding the tumor biology. Anahtar Kelimeler : PNET, Molecular biology, Pediatric brain tumor