Correlation between Histologic, Immunohistochemical and Molecular Classification of Medulloblastoma

Abstract

The 2021 WHO CNS5 establishes four molecularly-defined subgroups of MB with distinct clinical and prognostic associations (WNT-activated, SHH-activated and TP53-wildtype, SHH-activated and TP53-mutant and non-WNT/non-SHH). Molecular subtyping has become crucial in the diagnosis, risk-stratification and therapeutic planning. The gold standard for molecular subtyping is gene expression and methylation profiling methods which prove to be a major challenge for most hospitals due to cost and limited avaliability. Alternative methods such as immunohistochemical (IHC) and next-generation sequencing (NGS) analysis are required. Our aim is to assess the efficiency of an established IHC algorithm and customized NGS panel in samples from 15 patients with medulloblastoma to establish their molecular subtypes.