PATH-08. THE IMPORTANCE OF RE-DIAGNOSIS OF TUMORS PREVIOUSLY CLASSIFIED AS CENTRAL NERVOUS SYSTEM PRIMITIVE NEUROECTODERMAL TUMORS

BACKGROUND: The recent molecular analyses have revealed that central nervous system primitive neuroectodermal tumors (CNS PNETs) those having clusters of small round tumor cells are genetically different tumors. However, the concepts of CNS PNET are complicated, and it is difficult to diagnose them appropriately in clinical field. To overcome this difficulty, we reviewed previous studies associated with CNS PNETs, and carried out several approaches, those are relatively easy access to use in clinics, for our 8 samples of embryonal brain tumors diagnosed CNS PNETs in our institution, initially. METHODS: We used in combination with immunohistochemistry (IHC), Sanger sequence, Pyrosequence, polymerase chain reaction (PCR), real time PCR and copy number analysis referring recent reports. RESULTS: In terms of the diagnosis three out of 8 cases were changed based on the results in this study from previous diagnoses. CONCLUSION: In this review, it seemed that either the histopathological evaluation or molecular analyses would be not enough to make accurate diagnosis of CNS embryonal brain tumors, and it is essential to combine both of them including recent comprehensive analysis methods.